MAN Injectie Electronica EDC M.S 6.4

DIAGNOSIS Fault search programme The following error search programme contains the errors that can be detected by the error memory. The order of the tests corresponds to the numeric sequence of the flash codes, independent of the value of the error. So it is not arranged according to "Error is displayed by means of EDC indicator light" or "Error is not displayed by means of EDC indicator light". In addition to the flash code, the error location was recorded in hexadecimal figures, because this is displayed by MAN-cats. During the initial check on the vehicle, the entire error memory must always be read out and all the stored errors documented. A simple method of documentation is to make a screen copy (hardcopy) of the MAN-cats screen. This contains all the information (environmental conditions, etc.). This is important because during error search cables or components in the system have to be disconnected and there should be the capability of setting and storing the corresponding error messages. Because of this, the error memory should always be deleted again after intermediate tests. The test procedure for checking cables ("Test lines") must always be followed: Interruption or contact resistance (e.g. through stretched terminal sockets, plugs or terminal sockets pushed back, or oxidised plug connections) Short to minus Short to plus Short to adjacent wires Loose contacts Water or moisture in the wiring harness Wiring harnesses can also be damaged although the corrugated tube appears undamaged externally! All tests relating to the control device plugs are carried out with the aid of the diagnostic connector box (test box). The pin assignment on the control unit plug is identical to the test sockets on the diagnostic connector box. Where resistances are being measured, the control unit must be disconnected at the diagnostic connector box. Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit. After removal of the error and checking, repeat the test and delete the error memory. The error memory should always be deleted with MAN-cats.

Follow vehicle-related wiring diagrams! In the case of bus chassis (HOC) 3-character wire numbers and deviating item descriptions are mainly used. On all other vehicles in the present series (trucks and buses) only 5-character wire numbers and identical item descriptions are used.

T 17-A2

8.40 - 1

DIAGNOSIS TEST 1 Pedal sensor Flash code: Error location (hex):

1x short 81

Error display:

Yes (indicator light EDC on, or shown in display)

Error path:

Pedal sensor – Signal too high – Signal too low

Effect of error:

Torque reduced by 50 – 60% Default 50%

Possible cause of error:

Interruption on line, short-circuit, interruption in power supply, Pedal sensor faulty, control unit faulty

Condition for testing: Diagnostics connector box (test box) connected Ignition switched on Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Power supply

Voltage measurement at diagnostics connectors (test box) between Pin B16 (+) and Pin B35 (–)

− Test lines

Target value: 4.5 – 5.2 V Potentiometer signal

Voltage measurement at diagnostics connectors (test box) between Pin B23 (+) and Pin B35 (–) Target values: Idle speed: Full-load:

0.3 – 0.6 V 4.0 – 4.5 V

Error limits: U < 0.3 V or U > 4.8 V

T 17-A2

− Test plug connectors − If not fault found, try replacing the control unit − Test lines − Test plug connectors − Adjust linkage between accelerator pedal and pedal sensor − If adjustment is not possible, replace pedal sensor

8.40 - 3

DIAGNOSIS TEST 2 Quantity solenoid valve for fuel injection pump (plausibility of actuation duration) Flash code Error location (hex):

2x short 82

Error display:


Error path:

Actuation duration of the solenoid valve, quantity transferred on the CAN-bus to the pump

Effect of error:

Engine is shut down Engine does not start

Possible cause of error: Note:

Power supply (Ubat/earth), injection pump faulty Basically before replacing any pump or control unit the error memory should be deleted and the error observed. In practice, where there are several error entries, the corresponding test instructions should first be followed where they do not necessitate the exchange of a pump or control unit.

Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Injection pump

Voltage measurement between Pin 7 (+) and Pin 6 (–) at injection pump plug

− Test lines − Test plug connectors − Reprogram control unit to latest status

Target value: UBat

− If fault is still present, try replacing the injection pump* * Fitting and removing the injection pump and carrying out the associated adjustments is described in the repair manual for the A 14!

8.40 - 4

T 17-A2

DIAGNOSIS TEST 3 Engine speed sensor (flywheel) Flash code Error location (hex):

4x short 84

Error display:


Error path:

Engine speed sensor – Static: implausible – Dynamic: implausible

Effect of error:

Full load quantity reduced by 25 – 40% Final engine speed reduced to 1800 rpm The system switches from injection start control to control mode with prescribed injection start characteristic map; the engine is shut down if there are deviations are found in comparison with the pump speed sensor


Line interruption, short to earth, speed sensor faulty Sensor signal affected by metal filings, etc. at sensor's mounting position Distance from speed sensor to flywheel is incorrect, wrong flywheel Control unit faulty

Condition for testing: Diagnostics connector box (test box) connected Note:

This error can simultaneously arise with error 5x long, 1x short (speed sensor signal detection – pump control unit)

Follow vehicle-related wiring diagrams!

Test

Measurement

Remedy

Resistance

Resistance measurement at diagnostics connectors (test box) between Pin A1 (+) and Pin A13 (–)

− Test lines

Target value: 770 – 1000 Ω Engine speed signal

Signal test at diagnostics connector box (test box) with starting rpm between Pin A1 (+) and Pin A13 (–) with oscilloscope

− Test plug connectors − If no fault can be found, replace engine speed sensor − Test lines − Test plug connectors − If no fault can be found, replace control unit

Target value: see oscilloscope curves Gap between engine sped sensor and flywheel

Target value: 0.5 – 1.5 mm

T 17-A2

− Correct gap

8.40 - 5

DIAGNOSIS

TEST 4 Charge air pressure sensor Flash code Error location (hex):

5x short 85

Error display:


Error path:

Charge air pressure sensor – Signal too high – Signal too low – Signal implausible in combination with atmospheric pressure sensor (in control unit)

Effect of error:

Full-load quantity reduced by 20 – 40%, default 1200 mbar Black smoke during acceleration sequences


interruption on line, short-circuit, intake manifold pressure sensor faulty, intake manifold connection leak, atmospheric pressure sensor (in control unit) faulty, control unit faulty

Condition for testing: Diagnostics connector box (test box) connected Ignition switched on Application of pressure by pressure sensor with ALDA test device or Mitywac Duohand pump (absolute pressure gauge) Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Power supply

Voltage measurement at diagnostics connectors (test box) between Pin A23 (+) and Pin A17 (–)

− Test lines

Target value: 4.75 – 5.25 V Signal voltage

− Test plug connectors − If no fault can be found, replace control unit

Voltage measurement at diagnostics − Test lines connectors (test box) between Pin A12 (+) − Test plug connectors and Pin A17 (–) − If no fault can be found, replace Target values: intake manifold pressure sensor 1.50 – 1.70 V at 1500 mbar 2.70 – 3.00 V at 2000 mbar Error limits: U < 0.4 V or U > 4.5 V Characteristic curve with 5 V supply

Note: Absolute pressures are used in the above diagram! 8.40 - 6

T 17-A2

DIAGNOSIS TEST 5 Temperature sensor, coolant Flash code Error location (hex):

7x short 87

Error display:


Error path:

Temperature sensor, coolant

Effect of error:

Full load quantity reduced by 50% Formation of a default value (approx. 110 °C) Worse cold start performance


Interruption on line, short-circuit, temperature sensor faulty, control unit faulty

Condition for testing: Diagnostics connector box (test box) connected Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Sensor resistance Resistance measurement at diagnostics connector box (test box) between Pin A22 and Pin A5 Target values: 3.6 – 1.3 KΩ at 15 – 30 °C 460 – 230 Ω at 75 – 80 °C Sensor voltage

− Test lines − Test plug connectors − Replace temperature sensor − If no fault can be found, replace control unit

Voltage measurement at diagnostics − Test lines connectors (test box) between Pin A22 and − Test plug connectors Pin A5 − Replace temperature sensor Target value: 3.0 – 1.15 V at 30 – 90 °C Error limits: U < 0.53 V or U > 4.3 V

T 17-A2

− If no fault can be found, replace control unit

8.40 - 7

DIAGNOSIS TEST 6 Road speed signal Flash code Error location (hex):

8x short 88

Error display:


Error path:

Road speed transducer – Signal too high – Signal too low – No signal – Frequency too high

Effect of error:

All speed functions such as cruise control ("Tempomat"), speed control and maximum speed limiter are shut down No idle speed comparison


Interruption of line, plug connector in flexible steel-armoured cable is oxidising (ingress of water), short circuit, tachograph faulty

Condition for testing: Diagnostics connector box (test box) connected Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Signal line

Resistance measurement at diagnostics connector box (test box) between Pin B29 and tachograph Kl. B7

− Test lines

Target value: 0 Ω Voltage measurement at diagnostics connectors (test box) between Pin B29 and Pin B2 Target value: > 0.6 V

8.40 - 8

T 17-A2

− Test plug connectors − If no fault can be found, try replacing tachograph

DIAGNOSIS TEST 7 Pump control unit self-test (pump characteristic map not present) Flash code 9x short Error location (hex): 89 Error display:


Error path:

Pump control unit (pump characteristic map not present)

Effect of error:

Engine does not start


Pump control unit (injection pump) faulty Basically before replacing any pump or control unit the error memory should be deleted and the error observed. In practice, where there are several error entries, the corresponding test instructions should first be followed where they do not necessitate the exchange of a pump or control unit.

Note:

Test Injection pump

Measurement Remedy –––

− Delete error memory − Read error memory again − If fault still present, try replacing injection pump*

* Fitting and removing the injection pump and carrying out the associated adjustments is described in the repair manuals for the A 13 and A 14!

T 17-A2

8.40 - 9

DIAGNOSIS TEST 8 Shutdown via quantity 0 (after-running test) Flash code 1x long, 2x short Error location (hex): 92 Error display:


Error path:

Engine control unit, vehicle speed signal, injection pump

Effect of error:

Full-load quantity reduced by 25 – 40% because quantity can be inaccurate Final engine speed reduced to 2200 rpm

Function:

Quantity 0 is the default for after-running. If the expected fall in speed does not come about, it is classified as an error.

Possible cause of error: Note 1:

Note 2:

Engine control unit faulty, vehicle speed signal implausible, injection pump faulty Basically before replacing any pump or control unit the error memory should be deleted and the error observed. In practice, where there are several error entries, the corresponding test instructions should first be followed where they do not necessitate the exchange of a pump or control unit. In the event of errors in after-running, the road speed signal must also be checked. Reason: If the road speed transducer already shows 0 km/h when the vehicle is rolling and the ignition is then switched off, there is after-running. The various shutdown paths in after-running can then be classified as defective because the speed does not drop away fast enough (vehicle is rolling).

Follow vehicle-related wiring diagrams! Test

Measurement

Remedy

Engine control unit

Vehicle remains standing, speed is 800 rpm, multiple starting of engine (7 times) to delete error Minimal engine standstill period 5 s between attempts at starting

− Delete error memory

Injection pump

–––

− Read error memory once again − If no fault can be found, replace engine control unit − Delete error memory − Read error memory once again − If no fault can be found, replace injection pump*

Road speed signal

See test 6

− See test 6

* Fitting and removing the injection pump and carrying out the associated adjustments is described in repair manuals A 13 and A 14!

8.40 - 10

T 17-A2

DIAGNOSIS TEST 9 Undervoltage Flash code: Error location (hex):

1x long, 3x short 13

Error display:

No (indicator light EDC off, or nothing shown in display)

Error path:

Power supply for control unit (battery voltage too low < 9 V)

Effect of error:

Depending on the amount of the drop in voltage, the EDC system or engine may react in various ways: – engine does not start – engine runs very out of true – no output – high degree of smoke – contradictory error memory input


Battery discharged or faulty, generator faulty, interruption in line, short circuit, main relay faulty

Condition for testing: Diagnostics connector box (test box) connected Ignition switched on Follow vehicle-related wiring diagrams Test

Measurement

Remedy

Power supply

Voltage measurement at diagnostics connectors (test box) between Pin B15 (+) and Pin B1 (–) Pin B15 (+) and Pin B27 (–) Pin B3 (+) and Pin B2 (–) Pin B4 (+) and Pin B1 (–)

− Test lines − Test plug connectors − Replace main relay − If no fault can be found, replace control unit

Target value: 20 – 28 V

T 17-A2

8.40 - 11

DIAGNOSIS TEST 10 Proximity switch, brake Flash code: Error location (hex):


Error display:


Error path:

Proximity switch, brake signal

Effect of error:

FGR and ZDR not functioning


Interruption in line, proximity switch faulty or wrongly calibrated


Measurement

Remedy

Proximity switch brake signal


− Test lines

Brake pedal actuated

− Adjust proximity switch − Replace proximity switch

Target value: UBat Brake pedal not actuated Target value: 0 – 2 V

8.40 - 12

− Test plug connectors

T 17-A2

DIAGNOSIS TEST 11 Proximity switch, clutch Flash code: Error location (hex):


Error display:


Error path:

Proximity switch, clutch signal

Effect of error:

ZDR not functioning


Interruption to line, proximity switch faulty The control unit also detects errors if a speed of 30 km/h is exceeded and by then still no clutch signal has been detected


Measurement

Remedy

Proximity switch for clutch signal


− Test lines

Clutch pedal actuated

− Test plug connectors − Adjust proximity switch − Replace proximity switch

Target value: UBat Clutch pedal not actuated Target value: 0 – 2 V

T 17-A2

8.40 - 13

DIAGNOSIS TEST 12 Overspeed Flash code: 1x long, 7x short Error location (hex): 17 Error display:


Error path:

Engine overspeed

Effect of error:

Interruption in delivery of volume. If there are not further errors, delivery will resume after quitting the overspeed.


Incorrect operation, driver error (e.g. bad gearshift) Test –––

8.40 - 14

Measurement

Remedy

If not other error present no further actions are necessary

Delete error memory

T 17-A2

DIADNOSE TEST 13 Injection start deviation Flash code: 1x long, 8x short Error location (hex): 18 Error display:


Error path:

Injection start actuator unit, deviation

Effect of error:

Full load quantity reduced by 50 – 60% Final engine speed reduced to 1700 rpm Strong smoke development The system switched from closed-loop control to open-loop control with a predetermined injection start characteristic.


Fault in fuel system (leak, clogged, air in system) – Faulty or wrong overflow valve in pump's intake or return – Pre-delivery pump faulty – Empty tank – Tank ventilation faulty – Fuel filter defective (can result in pump contamination) Speed transducer signals incorrect Needle movement sensor signals incorrect (omitted from level 2 onwards) Basic configuration of pump is false Injection pump defective

Note:

The function paths needle movement sensor (omitted from level 2 onwards) and speed sensor (flywheel and injection pump) must always be checked in the case of this fault, even if there is no relevant error entered in the memory.

Follow the wiring diagrams relating to the vehicle. Test

Measurement

Remedy

Injection pump

Target value and actual value Check injection start

− Test fuel system

Error condition: +/– 3 degrees deviation, 2.5 s monitoring only if engine speed > 1000 rpm

− Test lines − Test plug connectors − Test pump installation* − Replace injection pump*

Needle movement sensor

See test 14

See test 14

Engine speed sensor

See test 3

See test 3


T 17-A2

8.40 - 15

DIAGNOSIS TEST 14 Needle movement sensor Flash code: Error location (hex):

1x long, 10x short 1A

Error display:


Error path:

Needle movement sensor – Signal not high enough – too few impulses – too many impulses – internal resistance wrong

Effect of error:

The system switches from closed-loop control to controlling the start of delivery. If the fault is no longer present, the system switches back to normal closed-loop control.


Interruption on line, short-circuit, needle movement sensor faulty The needle movement sensor becomes obsolete with the introduction of EDC 6.4 level 2!

Condition for testing: Diagnostics connector box (test box) connected Follow the wiring diagrams relating to the vehicle. Test

Measurement

Remedy

Internal resistance

Resistance measurement at diagnostics connector box (test box) between Pin A29 and Pin A15

− Test lines

Target values: 65 – 160 Ω See oscilloscope curves

− Test plug connectors − Replace needle movement sensor

Other possible causes of errors: − Faulty impulses from the speed sensor (even without error message) − Spurious pulses between the control unit and needle movement sensor (e.g. through relay switching) − Structure-borne noise effect on needle movement sensor through mechanical damage (e.g. valve train, piston) − Jet needle sticking Fault in fuel low-pressure system − − − − − − −

Faulty or wrong overflow valve Air or leaks in the system Faulty fuel pump Clogged filter Clogged lines Empty fuel tank Faulty injection pump

8.40 - 16

T 17-A2

DIAGNOSIS

TEST 15 Plausibility of solenoid valve shutdown (MAB signal) Flash code: 1x long, 11x short Error location (hex): 9B Error display:


Error path:

Status of solenoid valve shutdown

Effect of error:

Full load quantity reduced by 25 – 40% Final engine speed reduced to 2200 rpm Shutdown might not be possible via MAB

Function:

Check whether MAB status is the same in the pump control unit and the engine control unit


Line interruption between engine control unit and injection pump (pump control unit), engine control unit faulty, injection pump (pump control unit) faulty

Note:

Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Follow vehicle-related wiring diagrams Test

Measurement

Engine control unit

Voltage measurement at diagnostics − Test lines connectors (test box) between Pin B3 and − Test plug connectors Pin A20 − Delete error memory

Injection pump

Remedy

Target value: UBat with ignition on 0 V with ignition off

− Read error memory once again

–––


− If fault still present, try replacing the engine control unit − Read error memory once again − If fault still present, try replacing the injection pump*


T 17-A2

8.40 - 17

DIAGNOSIS TEST 16 Multi-level switch (resistor group) torque limiter Flash code: Error location (hex):

1x long, 12x short 1C

Error display:


Error path:

Multi-level switch (resistor group) torque limiters – voltage too high – voltage too low – wrong voltage

Effect of error:

No multilevel switch functions are possible

Function:

Voltage signals are detected via the multilevel input (control unit pin B28), whose values are determined by external resistance circuits. The limits can be programmed with MAN-cats.


Line interruption, short circuit, resistor group faulty (e.g. cold junction)


Measurement

Remedy

Resistor group

Voltage measurement at diagnostics connector box (test box) between Pin B28 and Pin B35

− Test lines

Target values: Handling characteristics: 0.75 – 1.25 V (resistance R 5 = 0.511 kΩ) Torque limiter: 1.75 – 2.25 V (resistance R 6 = 1.37 kΩ) Retarder active: 2.75 – 3.25 V (resistance R 7 = 3.09 kΩ) Speed limiter with special application: 3.75 – 4.25 V (resistance R 8 = 8.20 kΩ)

8.40 - 18

T 17-A2

− Test plug connectors − Replace resistor group − If no fault found, try replacing the control unit

DIAGNOSIS TEST 17 Operating unit (combination switch on steering column) Flash code: Error location (hex):

1x long, 13x short 1D

Error display:


Error path:

Operating unit (combination switch on steering column) faulty – Voltages false or implausible EOL programming faulty

Effect of error:

The cruise control is not functioning. Simultaneously all further functions of the operating unit such as intermediate speed control or idle speed control are not longer capable of activation. If the fault was only temporary (e.g. through multiple activation of the operating unit) the system will become operable again after switching the ignition off and then on again.

Function:

The operating unit is resistance-coded, in other words the control unit recognises every switching state by reference to the voltage that has been read in. It recognises an error if the wrong values are output over a certain period, e.g. through electrical faults but also through multiple activation (incorrect operation!) of the operating unit.


Interruption on line, short-circuit, operating unit faulty, EOL programming wrong


Measurement

Remedy

Operating unit


− Test lines

Switch on all switch positions of opreating unit determine the voltages Target values: SET+

0.83 – 1.21 V

SET–

2.53 – 2.97 V

MEMORY

1.60 – 2.00 V

AUS (OFF)

4.18 – 4.53 V

− Test plug connectors − Test EOL programming − Replace operating unit − If no fault can be found, try replacing control unit

Not activated 3.35 – 3.74 V

T 17-A2

8.40 - 19

DIAGNOSIS TEST 18 PBM interface (DKR/DKV) Flash code: Error location (hex):

1x long, 14x short 1E

Error display:


Error path:

PWM = Pulse-width-modulated signal Control unit input Pin B30 (DKR) and Pin B7 (DKV) – faulty – interrupted EOL programming faulty

Effect of error:

No intervention in quantity possible through PBM interface (e.g. ASR) No load-dependent gear changes (automatic transmission) possible


Short to minus, line interruption, EOL programming wrong

Note 1:

If the DKR line is interrupted (e.g. faulty control switch for ASR shutdown) then no DKV signal is emitted

Note 2:

The PWM interface is only active with partner systems without CAN

Condition for testing: Diagnostics connector box (test box) connected Ignition switched off Follow the wiring diagrams relating to the vehicle. Test

Measurement

Remedy

Lines to the partner system

Resistance measurement at diagnostics connector box (test box) between Pin B7 and Pin B1/B2

− Test line (including partner systems)

Target value: ∞ Ω

− Test EOL programming

Resistance measurement at diagnostics connector box (test box) between Pin B30 and Pin B1/B2

− Test line (including partner systems)

Target value: ∞ Ω

− If lines OK, continue fault search in partner system

Lines to the partner system

8.40 - 20

T 17-A2

− Test plug connector

− Test plug connector

DIAGNOSIS TEST 19 CAN 1 interface (ASR, GS, FM) Flash code: Error location (hex):

1x long, 15x short 1F

Error display:


Error path:

Engine control unit

Effect of error:

Data exchange between the EDC system and the connected electronic systems is interrupted


Interface error EOL programming wrong Control unit faulty

Note:

The CAN databus is described in the repair manual T 51


Measurement

Remedy

Control unit

Resistance measurement at diagnostics connector box between Pin B11 and Pin B12

− Test lines

Target value: ∼ 120 Ω

− Test plug connectors − At ca. 0 Ω short-circuit from CAN-H to CAN-L − Try replacing control unit

Error condition: 5 s no message received

T 17-A2

8.40 - 21

DIAGNOSIS TEST 20 Timeout: CAN signal ASR Flash code: Error location (hex):


Error display:


Error path:

CAN signal from ABS/ASR control unit faulty

Effect of error:

ASR not functioning


Line interruption, short-circuit, wrong EOL programming of the ABS control unit

Note:



Measurement

Remedy

EDC control unit


− Test lines

Target value: ∼ 120 Ω ABS/ASR control unit

− Test plug connectors − At ca. 0 Ω short-circuit from CAN-H to CAN-L

Error condition: Timeout period 5 s

− Try replacing control unit

Resistance measurement between Pin X1/3 and Pin X1/1

− Test lines − Test plug connectors − At ca. 0 Ω short-circuit from CAN-H to CAN-L

Target value: 60 Ω

− At ca. 120 Ω the connection to the terminator is broken − Test EOL programming

8.40 - 22

T 17-A2

DIAGNOSIS TEST 21 Shutdown via relay redundant shutdown MAR (after-running test) Flash code: Error location (hex):

2x long, 2x short A2

Error display:


Error path:

Relay, redundant shutdown (MAR), engine control unit

Effect of error:

Full load quantity reduced by 25 – 40% Final engine speed reduced to 2200 rpm Engine shutdown via MAR (relay redundant shutdown) impossible

Function:

The relay redundant shutdown (MAR = solenoid valve shutdown relay) is actuated by the engine control unit (pin B18) and in the individual case interrupts the power supply to the pump control unit. This leads to shutdown of the engine. In after-running the MAR is shut down (de-energised). If the expected fall in speed does not come about, it is classified as an error.


Line interruption, short-circuit, relay redundant shutdown (MAR) faulty, actuation from control unit faulty (engine control unit faulty), road speed signal implausible

Note:

In the event of errors in after-running, the road speed signal must also be checked. Reason: If the road speed transducer already shows 0 km/h when the vehicle is rolling and the ignition is then switched off, there is after-running. The various shutdown paths in after-running can then be classified as defective because the speed does not drop away fast enough (vehicle is rolling).

Condition for testing: Diagnostics connector box (test box) connected Ignition switched off Follow vehicle-related wiring diagrams Test

Measurement

Remedy

Pump relay (MAR)

Start engine and run at idling speed. − Test lines Pull bridge Pin B18 at diagnostics connector box (test box). Engine must shut down within − Test plug connectors 3s − Replace relay

Power supply MAR

Switch on ignition Voltage measurement at diagnostics connector box (test box) between Pin B18 and B2 Target value: UBat

− Test lines − Test plug connectors − If not fault can be found, replace the control unit

Switch off ignition Voltage measurement at diagnostics connector box (test box) between Pin B18 and B2 Target value: 0 V Road speed signal

See test 6

− See test 6

T 17-A2

8.40 - 23

DIAGNOSIS TEST 22 Timeout: CAN signal, transmission to EDC Flash code: Error location (hex):


Error display:


Error path:

CAN signal from transmission control unit faulty

Effect of error:

Restriction of functioning of transmission control


Interface error Line interruption, short-circuit Control unit faulty EOL programming wrong

Note:


Condition for testing: Diagnostics connector box (test box) connected Ignition switched off Follow the wiring diagrams relating to the vehicle.

Test

Measurement

Remedy

EDC control unit


− Test lines

Target value: ∼ 120 Ω Error condition: Timeout period 5 s

8.40 - 24

T 17-A2

− Test plug connectors − At ca. 0 Ω short-circuit from CAN-H to CAN-L − Try replacing the control unit

DIAGNOSIS

TEST 23 Pedal sensor (plausibility with brake) Flash code: Error location (hex):


Error display:


Error path:

Idle speed switch in pedal sensor – implausible to the brake signal Proximity switch, brake

Effect of error:

Speed diminishes to idling

Function:

This test is designed to check for a hanging or stuck accelerator pedal. In other words, the accelerator pedal is not in or not completely in its idle position and simultaneously a brake signal is detected. This situation can also be induced by simultaneous actuation of the brake and of the accelerator pedal.


Interruption on line, short-circuit, setting wrong, pedal sensor faulty, operator error

Condition for testing: Diagnostics connector box (test box) connected Ignition switched off Test 1 completed Follow the wiring diagrams relating to the vehicle. Test

Measurement

Remedy

Idle speed switch in pedal sensor See test 1

See test 1

Proximity switch, brake

See test 10

See test 10

T 17-A2

8.40 - 25

DIAGNOSIS

TEST 24 Main relay Flash code: Error location (hex):


Error display:


Error path:

Main relay – Contact sticks or hangs (does not open)

Effect of error:

This fault may not be noticed

Function:

The minus-side actuation of the relay coil takes place through the control unit via the control unit outlet pin B27. The main relay is de-energised with a time delay after switching off the ignition (after-running). During after-running, various computer functions are checked and any faults detected are stored in the error memory.


Short circuit, main relay faulty


Measurement

Remedy

Main relay


− Test lines

Target values: UBat with ignition off 0 V with ignition on

8.40 - 26

T 17-A2

− Test plug connectors − If line is OK, replace main relay

DIAGNOSIS TEST 25 Shutdown via monitoring module (after-running test) Flash code: 2x long, 6x short Error location (hex): A6 Error display:


Error path:

Engine control unit, pump control unit (injection pump), road speed signal

Effect of error:

Full load quantity reduced by 25 – 40% Final engine speed reduced to 2200 rpm Shutdown via monitoring module impossible

Function:

Microprocessor is tested for functioning through question/answer routine. In after-running false responses are sent intentionally, so that they lead to the engine shutting down. If the expected fall in speed does not come about, it is classified as an error.


Engine control unit faulty, pump control unit (injection pump) defective Road speed signal implausible

Note 1:


Note 2:


Follow the wiring diagrams relating to the vehicle.

Test

Measurement

Remedy

Engine control unit

–––

− Delete error memory − Read out error memory again − If fault still present, repalce engine control unit

Pump control unit (injection pump)

–––

− Delete error memory − Read out error memory again − If fault still present, repalce engine injection pump*

Road speed signal

See test 6

− See test 6


T 17-A2

8.40 - 27

DIAGNOSIS TEST 26 Atmospheric pressure sensor Flash code: Error location (hex):

2x long, 8x short A8

Error display:


Error path:

Atmospheric pressure sensor in control unit faulty

Effect of error:

No direct effects In individual case there may simultaneously be an error message from the intake manifold pressure sensor


Atmospheric pressure sensor (control unit) faulty

Test

Measurement

Remedy

Control unit

If only this error is stored, no test is possible because the sensor is inside the control unit.

− Replace control unit

However, if there is indication of a faulty intake manifold pressure sensor, this must first be put through test 4.

8.40 - 28

T 17-A2

DIAGNOSIS TEST 27 Solenoid valve for pump control unit Flash code: 2x long, 9x short Error location (hex): A9 Error display:


Error path:

Fuel injection pump

Effect of error:

Final engine speed reduced to 2000 rpm Full load quantity reduced by 25 – 40% Engine is shut down Engine does not start

Function:

A failed output stage/short-circuit is diagnosed via measurement of voltage in pump control unit


Speed sensor on flywheel has a loose contact, injection pump defective Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:


Measurement

Engine speed sensor

See test 3

Injection pump

–––

Remedy − See test 3 − Delete error memory − Read error memory again − If error still present, replace injection pump*


T 17-A2

8.40 - 29

DIAGNOSIS TEST 28 Timeout: CAN signal ASR to engine brake Flash code: Error location (hex):

2x long, 10x short 2A

Error display:


Error path:

CAN signal from ABS/ASR control unit to engine brake

Effect of error:

ASR does not actuate the engine brake


Interruption on line, short-circuit, control unit faulty

Note:


Condition for testing: Diagnostics connector box (test box) connected Ignition switched off Follow vehicle-related wiring diagrams

8.40 - 30

Test

Measurement

Remedy

EDC control unit

See test 19

− See test 19

ABS/ASR control unit

See test 20

− See test 20

T 17-A2

DIAGNOSIS TEST 29 Timeout: CAN signal transmission to engine brake Flash code: Error location (hex):

2x long, 11x short 2B

Error display:


Error path:

CAN signal from transmission control to engine brake

Effect of error:

Transmission control does not actuate the engine brake



Note:



Measurement

Remedy

EDC control unit

See test 19

− See test 19

T 17-A2

8.40 - 31

DIAGNOSIS TEST 30 Timeout: CAN signal, vehicle management to engine brake Flash code: Error location (hex):

2x long, 12x short 2C

Error display:


Error path:

CAN signal from vehicle management to engine brake

Effect of error:

Vehicle management does not actuate the engine brake



Note:



8.40 - 32

Test

Measurement

Remedy

EDC control unit

See test 19

− See test 19

T 17-A2

DIAGNOSIS TEST 31 Timeout: CAN signal, vehicle management to EDC Flash code: Error location (hex):

2x long, 13x short 2D

Error display:


Error path:

CAN signal from vehicle management to EDC

Effect of error:

No intervention in volume by vehicle management



Note:



Measurement

Remedy

EDC control unit

See test 19

− See test 19

T 17-A2

8.40 - 33

DIAGNOSIS TEST 32 Timeout: CAN signal transmission to EDC Flash code: Error location (hex):

2x long, 14x short 2E

Error display:


Error path:

CAN signal from transmission to EDC

Effect of error:

No intervention in volume by transmission



Note:



8.40 - 34

Test

Measurement

Remedy

EDC control unit

See test 19

− See test 19

T 17-A2

DIAGNOSIS TEST 33 After-running control Flash code: Error location (hex):


Error display:


Error path:

Control unit for actuation output faulty – Computer after-running has not taken place

Effect of error:

Final engine speed reduced to 2200 rpm Full load quantity reduced by 25 – 40%

Function:

After-running automatically takes place after each shutdown procedure


Power supply for control unit for after-running is not secured EOL not completed


Measurement

Remedy

Power supply to control Voltage measurement at diagnostics unit connector box (test box) between Pin B3/B4 and Pin B1/B2 Target values: UBat with ignition off as long as after-running takes place in control unit. Main battery switch is held by the EDC control unit (holding circuit)

− Test lines − Test plug connectors − Test after-running circuit − Test main relay

Error condition: Relay must have responded within 5 s

Oscilloscope measurement on switching ignition on and off ON

OFF

CH 2: 10.0 V 200 ms CH 2: 10.0 V 200 ms

CH 1: 10.0 V 200 ms

CH 1: 10.0 V 200 ms CH 1: Pin B1–B3 CH 2: Pin B15–B1

CH 1: Pin B1–B3 CH 2: Pin B15–B1

If Pin B1–B3 is live for 5 s longer than Pin B15–B1, there is a "main relay" fault classification T 17-A2

8.40 - 35

DIAGNOSIS TEST 34 Pump control unit self-test: Solenoid valve voltage measurement Flash code: Error location (hex):

4x long, 1x short C1

Error display:


Error path:


Effect of error:

None known of

Function:

Monitoring of voltage in self-test if solenoid valve is not actuated


Pump control unit (injection pump) faulty Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:

Test Injection pump

Measurement –––

Remedy − Delete error memory − Read error memory once again − If fault still present, try replacing the injection pump*


8.40 - 36

T 17-A2

DIAGNOSIS TEST 35 Pump temperature (pump control unit) Flash code: Error location (hex):


Error display:


Error path:

Injection pump (pump control unit) fuel temperature too high

Effect of error:

If the values are implausible there is a switch to substitute value (75 °C)


Fuel temperature too high, sensor in pump defective, injection pump faulty

Note:


Test

Measurement

Remedy

Injection pump

Error limits:


If implausible values t > 130 °C or t < –45 °C the substitute value is set

− Read error memory once again − If fault still present, try replacing the injection pump*


T 17-A2

8.40 - 37

DIAGNOSIS TEST 36 Busoff: CAN 2 signal Flash code: Error location (hex):


Error display:


Error path:

CAN signal between pump control unit and engine control unit on switching on (busoff)

Effect of error:

Engine goes into fast idling (ca. 750 rpm), acceleration now impossible


Interruption on line, short-circuit, control unit faulty, injection pump faulty

Note:



Measurement

Remedy

Engine control unit

Resistance measurement at diagnostics control box between Pin A27 and A24

− Test lines − Test plug connectors − At ca. 0 Ω short-ciruit from CAN-H to CAN-L

Target value: ∼120 Ω

− If fault is still present, try replacing the control unit Injection pump

–––

− Delete error memory − Read error memory once again − If fault is still present, try replacing the injection pump*


8.40 - 38

T 17-A2

DIAGNOSIS TEST 37 CAN 2 signal (interface) Flash code: Error location (hex):


Error display:


Error path:

CAN signal to pump control unit on switching on

Effect of error:

Engine goes into fast idling (ca. 750 rpm), acceleration now impossible


Interface error Injection pump (pump control unit) faulty Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:

Test Injection pump




T 17-A2

8.40 - 39

DIAGNOSIS TEST 38 Shutdown via quantity solenoid valve (after-run test) Flash code: Error location (hex):


Error display:


Error path:

Status of solenoid valve shutdown (MAB) in after-running

Effect of error:

Final engine speed reduced to 2200 rpm Full load quantity reduced by 25 – 40%, impossible to shutdown engine via MAR (high-pressure solenoid valve in injection pump)


Actuation of control unit is faulty (engine control unit defective) Injection pump (pump control unit) faulty Road speed signal implausible

Note 1:


Note 2:


Condition for testing: Diagnostics connector box (test box) connected Follow vehicle-related wiring diagrams Test

Measurement

Remedy

Injection pump

–––

− Delete error memory − Read error memory once again − If fault still present, try replacing the injection pump*

Engine control unit

See test 15

− See test 15

Road speed signal

See test 6

− See test 6


8.40 - 40

T 17-A2

DIAGNOSIS TEST 39 Busoff: CAN 1 signal Flash code: Error location (hex):


Error display:


Error path:

Vehicle CAN (busoff)



Note 1:


Note 2:



Measurement

Remedy

Engine control unit

Resistance measurement at diagnostics control box between Pin B11 and B12



− Try replacing the control unit

T 17-A2

8.40 - 41

DIAGNOSIS TEST 40 Pump speed sensor (IWZ signal) Flash code: Error location (hex):


Error display:


Error path:

Fuel system Fuel injection pump

Effect of error:

Engine shuts down

Function:

Refer to page 3.02 - 14


Fault in fuel system (leak, clogged, air in system) Injection pump defective (dynamic: implausible, static; increments per segment not complete)

Note 1:


Note 2:

The fuel system layout (low pressure) is shown in the repair manuals A 13 and A 14.

Test

Measurement

Remedy

Fuel system

Fuel pressure

− Vent (filter, then injector line at at least 3 injection nozzles) − After successful start, leave engine idling for at least 30 s − Fill the tank

Injection pump

–––

− Test pump installation* − Delete error memory − Read error memory once again − If fault still present, try replacing the injection pump*


8.40 - 42

T 17-A2

DIAGNOSIS

TEST 41 Residual quantity Flash code: Error location (hex):


Error display:


Error path:

CAN signal (quantity that is transferred to the pump on the CAN-bus)

Effect of error:

Engine stops because calculation of quantities inaccurate

Function:

If despite the quantity "quantity 0" being specified on the CAN the speed is >700 rpm, the boost pressure >300 mbar and NBF signals (only with level 1) are detected, there is classification as an error


Line interruption, short-circuit, control unit defective, NBF (only in level 1) faulty, intake manifold pressure sensor faulty

Note:

Before any replacement of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit. Test

Measurement

Remedy

Injection pump

–––


Intake manifold pressure sensor

See test 4

− See test 4

Needle movement sensor

See test 14

− See test 14


T 17-A2

8.40 - 43

DIAGNOSIS TEST 42 Pump control unit self-test: solenoid valve output stage Flash code: Error location (hex):


Error display:


Error path:

Hardware error in solenoid valve output stage (pump control unit)

Effect of error:

None known of

Function:

Checking of output stage in PSG self-test


Pump control unit (injection pump) faulty Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:

Test Injection pump

Measurement Remedy –––



8.40 - 44

T 17-A2

DIAGNOSIS TEST 43 Injection timing device (pump control unit) Flash code: 4x long, 10x short Error location (hex): CA Error display:


Error path:

Target-actual value exceeding/not reaching injection timing device

Effect of error:

Final engine speed reduced to 1700 rpm Full load quantity reduced by 50 – 60%


Line interruption, short-circuit Fault in fuel low-pressure system – faulty or wrong overflow valve – air or leaks in the system – faulty pre-supply pump – blocked filters – clogged lines – empty fuel tank – faulty injection pump – faulty fuel filter

Note 1:


Note 2:

The fuel pipework layout (low pressure) is shown in the repair manuals A 13 and A 14.

Test

Measurement

Remedy

Injection pump

Error condition:


In case of deviation of target − Read error memory once again from actual value for injection − If fault still present, try replacing the start by more than injection pump* +/– 3 grad longer than 8 s and speed > 1200 rpm Fuel system

Fuel pressure

− See above (possible cause of error)


T 17-A2

8.40 - 45

DIAGNOSIS TEST 44 Timeout: CAN signal PSG 1 Flash code: Error location (hex):

4x long, 11x short CB

Error display:


Error path:

CAN signal from pump control unit to engine control unit (timeout)

Effect of error:

Engine goes into increased idling speed


Line interruption, short-circuit, control unit faulty, injection pump faulty

Note:



Measurement

Remedy

Engine control unit





–––



8.40 - 46

T 17-A2

DIAGNOSIS TEST 45 Shutdown via voltage monitoring (after-running test) Flash code: 4x long, 12x short Error location (hex): 99 Error display:


Error path:

Status shutdown via voltage monitoring)

Effect of error:

Final engine speed reduced to 2200 rpm Torque reduced by 25 – 40%, shutdown via voltage monitoring impossible

Function:

In after-running, an error is consciously simulated (limit values). If the expected fall in speed does not come about, it is classified as an error.


Line interruption between engine control unit and injection pump (pump control unit), engine control unit faulty, injection pump (pump control unit) faulty If additionally the error "Plausibility shutdown signal (MAB)" or "Shutdown via monitoring module" occurs, check MAB line.

Note 1:


Note 2:


Follow vehicle-related wiring diagrams Test Engine control unit


Remedy − Delete error memory − Read error memory once again − If fault still present, try replacing the engine control unit


–––


Road speed signal

See test 6

− See test 6


T 17-A2

8.40 - 47

DIAGNOSIS TEST 46 Timeout: CAN signal MSG 1 Flash code: Error location (hex):

4x long, 13x short B1

Error display:


Error path:

CAN signal from engine control unit to pump control unit (timeout)

Effect of error:

Final engine speed reduced to 2000 rpm Torque reduced by 25 – 40%


Line interruption, short-circuit, control unit faulty, injection pump faulty Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.


Measurement

Remedy

Engine control unit





–––



8.40 - 48

T 17-A2

DIAGNOSIS TEST 47 Supply voltage, pump control unit Flash code: Error location (hex):


Error display:


Error path:

Power supply to pump control unit, relay, redundant shutdown (MAR)

Effect of error:

Engine shuts down Engine does not start


Line interruption, short-circuit

Condition for testing: See below Follow vehicle-related wiring diagrams Test

Measurement

Remedy

Power supply

Voltage measurement at cable loom plug to PSG between Pin 7 (+) and Pin 6 (–)

− Test line − Test plug connection

Target value: UBat Error limits: U < 7 V or U > 32 V Relay redundant shutdown (MAR)

Switch on ignition

− Test line


− Test plug − Replace relay (MAR)

Target value: UBat Switch off ignition Disconnect engine control unit Resistance measurement at diagnostics control box between Pin B18 and Pin B1 Target value: 180 – 250 Ω

Plug for pump control unit

T 17-A2

8.40 - 49

DIAGNOSIS

TEST 48 CAN signal, pump control unit (interface) Flash code: Error location (hex):


Error display:


Error path:

CAN signal to pump control unit (timeout value range violation)

Effect of error:

Engine goes into increased idling speed Engine shuts down


Line interruption, short-circuit, control unit faulty, injection pump faulty, engine speed sensor flywheel faulty

Note:



Measurement

Remedy

Engine control unit




− If fault still present, try replacing control unit Injection pump

–––


Engine speed sensor

See test 3

− See test 3


8.40 - 50

T 17-A2

DIAGNOSIS TEST 49 Speed sensor signal detection, pump control unit Flash code: Error location (hex):


Error display:


Error path:

Engine speed signal to the pump control unit

Effect of error:


Function:

Monitoring on negative flank in data collection window


Speed sensor flywheel faulty, sensor distance false (target: 0.5 – 1.5 mm). Control unit faulty, injection pump installation wrong, injection pump faulty. "Injection start deviation" is sometimes displayed when there is a loose contact. The error "Speed sensor at flywheel" often appears at the same time

Note:


Test

Measurement

Remedy

Engine speed sensor

See test 3

− See test 3

Injection pump

–––


Cables

Line between Pin A35 − Test lines engine control unit and Pin 8 − Test plug connectors pump control unit


T 17-A2

8.40 - 51

DIAGNOSIS TEST 50 Pump control unit self-test: EEPROM checksum Flash code: Error location (hex):


Error display:


Error path:

Checksum test EEPROM

Effect of error:

Final engine speed reduced to 1700 rpm Torque reduced by 50 – 60%, as injection timing device can go to advance stop

Function:

Checksum test in self-test


Control unit faulty, pump control unit (injection pump) defective Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:

Test Fuel injection pump




8.40 - 52

T 17-A2

DIAGNOSIS TEST 51 Pump control unit self-test: EEPROM status Flash code: 5x long, 3x short Error location (hex): B6 Error display:


Error path:

Status check EEPROM (hardware error)

Effect of error:

Final engine speed reduced to 1700 rpm Torque reduced by 50 – 60%, as injection timing device can go to advance stop

Function:

Hardware check in self-test


Control unit faulty, pump control unit (injection pump) defective Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:





T 17-A2

8.40 - 53

DIAGNOSIS TEST 52 Pump control unit self-test: ADC status Flash code: 5x long, 4x short Error location (hex): B2 Error display:


Error path:

Status analog-digital converter

Effect of error:


Function:

In the self-test checking earth potential of a channel of the AD converter there is no quantity correction Solenoid valve voltage is no longer acquired


Control unit faulty, injection pump defective Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:





8.40 - 54

T 17-A2

DIAGNOSIS TEST 53 Pump control unit self-test: RAM Flash code: 5x long, 5x short Error location (hex): B9 Error display:


Error path:

RAM in pump control unit

Effect of error:

Engine does not start

Function:

Checking RAM in self-test


Control unit faulty, injection pump defective Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:





T 17-A2

8.40 - 55

DIAGNOSIS TEST 54 Polarity reversal, speed sensor on flywheel Flash code: 5x long, 6x short Error location (hex): 91 Error display:


Error path:

Speed sensor on flywheel

Effect of error:



Cable plugged in wrongly, fault in speed sensor


Measurement

Remedy

Cables

Plug connection X337

− Cable should be assigned correctly

X337 Pin e: cable colour white/blue X337 Pin F: cable colour blue

− If fault still present, try replacing the speed sensor

Engine control unit Pin A1: cable colour white/blue Pin A13: cable colour blue Error condition: Lower speed threshold: 500 rpm Upper speed threshold: 1500 rpm

8.40 - 56

T 17-A2

DIAGNOSIS TEST 55 Engine control unit monitoring module (µ µ-controller) Flash code: 5x long, 7x short Error location (hex): 96 Error display:


Error path:

µ-Controller in engine control unit

Effect of error:

Engine shuts down


Control unit faulty Before any exchange of pump or control units the error memory should always be deleted and the error observed. If there are a number of error entries, the corresponding test instructions should generally only be taken into account where they do not require a change of pump or control unit.

Note:

Test Control unit


Remedy − Delete error memory − Read error memory once again − If fault still present, try replacing the control unit

T 17-A2

8.40 - 57

DIAGNOSIS TEST 56 Pump control unit initialisation Flash code: 5x long, 8x short Error location (hex): CD Error display:


Error path:

Exchange of messages between pump control unit and engine control unit takes too long

Effect of error:


Function:

In the self-test the exchange of messages between the pump control unit and engine control unit is monitored for duration. If the time interval is too long, there is an error classification.


Pump control unit (injection pump) faulty CAN bus between engine control unit and pump control unit is defective

Note:






8.40 - 58

T 17-A2

DIAGNOSIS TEST 57 Multi-level switch (resistor group), maximum speed limiter Flash code: Error location (hex):

6x long, 6x short DB

Error display:


Error path:

Multi-level switch (resistor group) for maximum speed limiters – voltage too high – voltage too low – wrong voltage

Effect of error:

No multilevel switch functions are possible

Function:

Voltage signals are detected via the multilevel inputs (control unit pin B19), whose values are determined by external resistance circuits. The limits (HGB 1, 2 and 3) can be programmed with MAN-cats.


Line interruption, short circuit, resistor group faulty (e.g. cold junction)

Note 1:

The maximum speed limiters via the multilevel switch (control unit pin B19) are only implemented from level 2 onwards. In level 1, HGB 2 is activated by wiring pin B21 with UBat. HGB 3 is not possible with level 1.

Note 2:

Activation of another maximum speed limit (e.g. by a changeover switch) is only possible at below a road speed of 10 km/h!


Measurement

Remedy

Resistor group


− Test lines

Target values: Maximum speed limit 1: 0.75 – 1.25 V (resistance R 1, 0.511 kΩ)

− Test plug-in connections − Replace resistor group − If no fault is found, try replacing the control unit

Maximum speed limit 2: 1.75 – 2.25 V (resistance R 2, 1.37 kΩ) Maximum speed limit 3: 2.75 – 3.25 V (resistance R 3, 3.09 kΩ)

T 17-A2

8.40 - 59

DIAGNOSIS TEST 58 Error when sending a CAN message Flash code: 6x long, 11x short Error location (hex): E0 Error display:


Error path:

Engine control unit

Effect of error:

None known of


CAN from engine control unit faulty

Test Control unit

8.40 - 60

Measurement See Test 19

T 17-A2

Remedy − See Test 19

DIAGNOSIS TEST 59 Test on shutdown paths Flash code: 6x long, 12x short Error location (hex): E1 Error display:


Error path:

Road speed signal

Effect of error:

None known of

Function:

After-running automatically takes place after each shutdown When the permissible number of shutdowns has been exceeded without afterrunning, it is classified as an error


Road speed signal faulty In the event of errors in after-running, the road speed signal must also be checked. Reason: If the road speed transducer already shows 0 km/h when the vehicle is rolling and the ignition is then switched off, there is after-running. The various shutdown paths in after-running can then be classified as defective because the speed does not drop away fast enough (vehicle is rolling).

Follow vehicle-related wiring diagrams Test Road speed signal

Measurement See Test 6

T 17-A2

Remedy See Test 6

8.40 - 61

DIAGNOSIS

TEST 57 Engine brake Flash code: Error location (hex):

No data acquisition No data acquisition

Error display:

No data acquisition

Error path:

Engine brake, engine brake switch

Effect of error:

No engine brake function

Function:

The engine brake is actuated corresponding to the engine speed via Pin A18 (output) of the EDC control unit. Actuation takes place by supplying current to Pin B14 (input) of the EDC control unit by actuation of the foot control switch for the engine brake. Actuation can also take place from the transmission control or vehicle management through a CAN message.


Line interruption, short-circuit, engine brake switch faulty

Condition for testing: Diagnostics connector box (test box) connected Note 1:

The engine brake function can also be switched off by other systems, e.g. by the ABS control unit during a braking controlled under ABS. For this reasons the ABS system should be included when fault finding. A clutch signal coming from a faulty or incorrectly adjusted proximity switch can also lead to failure of the engine brake.

Note 2:

On part of the EDC control units 6.4 level 1 the engine braking activation functions by the "flip-flop" principle, i.e. when the engine brake is actuated at a speed of >800 rpm, the engine brake stays active even though the control switch is no longer actuated. Only when the foot control switch is activated again or the brake, clutch or accelerator pedal are operated is the engine brake deactivated. During EOL programming, the flip-flop switching is automatically deactivated however and can also not be re-activated!


Measurement

Remedy

Power supply from engine brake control switch

Voltage measurement at diagnostics connector box (test box) between Pin B14 (+) and Pin B1/2 (-)

− Test line

Target values:

Solenoid valve, engine brake

− Is bridge on ZE, position 61 plugged in?

Foot control switch, engine brake actuated: UBat

− Replace engine brake control switch

Voltage measurement at diagnostics connector box (test box) between Pin A18 (+) and Pin B1/2 (-)

− Test line

Start engine and run up to approx. 1100 rpm Target values: Foot control switch, engine brake actuated: Ubat engine brake must function

8.40 - 62

− Test plug-in connection

T 17-A2

− Test plug-in connection − Replace solenoid valve, engine brake − If no fault is found, try replacing the control unit

DIAGNOSIS TEST 58 FGB/FGR switch Flash code: Error location (hex):


Error display:

No data acquisition

Error path:

FGB/FGR switch

Effect of error:

No switchover to FGB is possible

Function:

Refer to page 3.01 - 3


Line interruption, short-circuit, FGR/FGB switch faulty


Measurement

Remedy

Supply voltage

Switch on ignition Voltage measurement at diagnostics connector box (test box) between Pin B22 (+) and Pin B1/2 (-)

− Test line − Test plug-in connection − Test/replace FGB/FGR switch

Target values: FGB/FGR switch activated: UBat

T 17-A2

8.40 - 63

DIAGNOSIS TEST 59 Relay, redundant shutdown MAR (safety relay) Flash code: Error location (hex):


Error display:

No data acquisition

Error path:

Relay, redundant shutdown (safety relay)

Effect of error:

Engine shuts down Engine does not start

Function:

The safety relay fulfils an important function as an independent, higher ranking (redundant) shutdown facility of the engine. Actuation of the safety relay takes place in certain emergency situations when shutting down the engine by control to zero is no longer possible. The safety relay is actuated by the engine control unit Pin B18 and interrupts the power supply to the pump control unit (Pin 7). This leads to immediate engine shutdown.


Line interruption, short circuit, safety relay faulty, actuation by the control unit faulty (control unit faulty)


Measurement

Remedy

Function safety relay

Start engine and run at upper idling speed (control speed PWG max) Interrupt Pin B18 Engine must shut down within approx. 10 seconds

Supply voltage

Switch on ignition Voltage measurement at diagnostics connector box (test box) between Pin B18 (+) and Pin B1 (-) Specified value: UBat

Coil resistance, safety relay

Switch on ignition Voltage measurement at diagnostics connector box (test box) between Pin B18 (+) and Pin B1 (-) Specified value: 180 – 250 Ω

8.40 - 64

T 17-A2

− Test line − Test plug-in connection − Replace safety relay If no fault can be found: − Replace control unit − Test line − Test plug-in connection − Replace safety relay

MAN Injectie Electronica EDC M.S 6.4

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