[4] Check component Y94 (Quantity control valve).: Signal faulty

[4] Check component Y94 (Quantity control valve).: Signal faulty

Test 1: Check component Y94 (Quantity control valve).

Test 2: Signal wire Check component Y94 (Quantity control valve).

Test 3: Signal line Short circuit

1. Check component Y94 (Quantity control valve).

Test 1.1: Check power supply of component Y94 (Quantity control valve).

Test 1.2: Check components of high pressure control circuit.

1.1. Check power supply of component Y94 (Quantity control valve).
Check actual value Y94 (Quantity control valve).
Test prerequisite

- Engine at idle
Status of relevant actual value:
- On/off ratio of component Y94 (Quantity control valve):Warning! Communication with ECU required.
Specified value

- On/off ratio:>30%
Question

- Is the actual value o.k.?


YES
The actual value is okay.Test wiring and plug connections between control module N3/9 (CDI control unit) and Y94 (Quantity control valve) for Loose contact, repair or replace if necessary.End of test

NO
Voltage supply of component Y94 (Quantity control valve)
Test prerequisites:

- The actual value is not o.k.
Figure legend

- Y94 (Quantity control valve)
Special tool

- Adapter cable220 589 00 99 35
Test sequence

- Switch off ignition.
- Connect adapter cable to component Y94 (Quantity control valve).
- Ignition ON
- Measure direct voltage with multimeter between sockets (Y94) 1 and (Y94) 2
Specified value

- Voltage[11...14] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further possible causes of fault

- Inspect cables and plug connections between component Y94 (Quantity control valve) and control module N3/9 (CDI control unit) for loose contact, damage and corrosion, repair or replace if necessary.
End of test

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

- Test lines between components N3/9 (CDI control unit) and Y94 (Quantity control valve) for Open circuit.
End of test

1.2. Check components of high pressure control circuit.
Check components of high pressure control circuit.
Important notes

- This test is used to check the entire high pressure control circuit.
- In the case of complaints related to a cold start or to the warm-up phase, do not bring the engine to operating temperature, but proceed as appropriate for the complaint.
- If no faulty components are identified during the test, do not replace any components.
Test prerequisites

- Compression test in menu 'Actuations' was carried out.
- The pressure of the fuel low pressure system is OK.
Communication with ECU required

2. Signal wire Check component Y94 (Quantity control valve).
Check actual value Y94 (Quantity control valve).
Test prerequisite

- Engine at idle
Status of relevant actual value:
- On/off ratio of component Y94 (Quantity control valve):Warning! Communication with ECU required.
Specified value

- On/off ratio:>30%
Question

- Is the actual value o.k.?


YES
The actual value is okay.Test wiring and plug connections between control module N3/9 (CDI control unit) and Y94 (Quantity control valve) for Loose contact, repair or replace if necessary.End of test

NO
Voltage supply of component Y94 (Quantity control valve)
Test prerequisites:

- The actual value is not o.k.
Figure legend

- Y94 (Quantity control valve)
Special tool

- Adapter cable220 589 00 99 35
Test sequence

- Switch off ignition.
- Connect adapter cable to component Y94 (Quantity control valve).
- Ignition ON
- Measure direct voltage with multimeter between sockets (Y94) 1 and (Y94) 2
Specified value

- Voltage[11...14] V
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further possible causes of fault

- Inspect cables and plug connections between component Y94 (Quantity control valve) and control module N3/9 (CDI control unit) for loose contact, damage and corrosion, repair or replace if necessary.
End of test

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

- Test lines between components N3/9 (CDI control unit) and Y94 (Quantity control valve) for Open circuit.
End of test

3. Signal line Short circuit

Test 3.1: Read actual value of component Y94 (Quantity control valve).

3.1. Read actual value of component Y94 (Quantity control valve).
Test prerequisite

- Engine at idle
- Briefly blip throttle.
Status of relevant actual value:
- On/off ratio of component Y94 (Quantity control valve):Warning! Communication with ECU required.
Specified value

- On/off ratio:<30%
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
The actual value is not o.k.Possible cause and remedy

- This test did not produce any clear result.
- Test cable Y94 (Quantity control valve)- N3/9 (CDI control unit) for Open circuit, repair if necessary.