[4] Maximum vehicle speed limit: Signal faulty

[4] Maximum vehicle speed limit: Signal faulty

Test 1: Check component Y74 (Pressure control valve).

1. Check component Y74 (Pressure control valve).
Test prerequisite

- Operate engine at idling speed.
- Fuel temp. of > 20°
- Carry out the test within 30 s.
Status of relevant actual value:
- On/off ratio of component Y74 (Pressure control valve):Warning! Communication with ECU required.

- Fuel temperature:Warning! Communication with ECU required.
Specified value

- On/off ratio:<30%
- Fuel temp. of > 20°
Question

- Is the actual value o.k.?


YES
The actual value is okay.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
Test signal voltage of component Y74 (Pressure control valve).
Figure legend

- Y74 (Pressure control valve)
Special tool

- Adapter cable220 589 00 99 35
Test prerequisite

- Operate engine at idling speed.
- Fuel temp. of > 20°
- Carry out the test within 30 s.
Test sequence

- Switch off ignition.
- Detach coupling at component Y74 (Pressure control valve).
- Connect adapter cable no. 220 589 00 99 35 to engine wiring harness Y74 (Pressure control valve).
- Measure direct voltage with multimeter between sockets (Y74/x1) 1 and (Y74/x1) 2
Specified value

- Voltage[1,7...2,0] V
Question

- Is the measurement value OK?







YES
Test current consumption of component Y74 (Pressure control valve).
Figure legend

- Y74 (Pressure control valve)
Special tool

- Adapter cable220 589 00 99 35
Test sequence

- Switch off ignition.
- Detach coupling at component Y74 (Pressure control valve).
- Connect adapter cable no. 220 589 00 99 35 to engine wiring harness Y74 (Pressure control valve).
- Operate engine at idling speed.
- Measure direct current with multimeter between sockets (Y74/x1) 1 and (Y74/x1) 2
Specified value

- Current[650...700] mA ca.4sec.
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
Check internal resistance of component Y74 (Pressure control valve).
Figure legend

- Y74 (Pressure control valve)
Special tool

- Adapter cable220 589 00 99 35
Test sequence

- Switch off ignition.
- Detach coupling at component Y74 (Pressure control valve).
- Connect adapter cable no. 220 589 00 99 35 at component Y74 (Pressure control valve).
- Measure resistance with multimeter between sockets (Y74) 1 and (Y74) 2
Specified value

- Resistor[3 ... 5]ohms
Question

- Is the measurement value OK?







YES
The measurement value is OK.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
- Test wiring from component N3/9 (CDI control unit) to component Y74 (Pressure control valve) with an ohmmeter for short circuit (positive or negative) and repair, if necessary.
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Replace component Y74 (Pressure control valve).
Note

- After replacing the pressure regulator valve, the teach-in process for this component must be performed via menu 'Control unit adaptations'.
End of test

NO
The measurement value is OK.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test