Operation CHARM: Car repair manuals for everyone.

Manufacturer Code Charts: 109800


The signal voltage of component B50 (Fuel temperature sensor) is too high.


Possible cause:

- B50 (Fuel temperature sensor)
Affected functions:

- Power generation

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Test 1: Check component B50 (Fuel temperature sensor).

1. Check component B50 (Fuel temperature sensor).
Check actual value B50 (Fuel temperature sensor).
Figure legend

- B50 (Fuel temperature sensor)
- Y94 (Quantity control valve)
Note

- The fault code is stored even if the lines to component B50 (Fuel temperature sensor) are interrupted.
Test prerequisite

- The plug on component B50 (Fuel temperature sensor) is not disconnected.
Test sequence

- Switch on ignition.
Status of relevant actual value:
- Fuel temperature:Warning! Communication with ECU required.
Specified value

- The actual value must be plausible.
- If the connection is unplugged at component B50 (Fuel temperature sensor), the value is approx. -40° C.
Question

- Is the actual value o.k.?







YES
The actual value is okay.Further procedure

- Test wiring and plug connections between control module N3/9 (CDI control unit) and B50 (Fuel temperature sensor) for Loose contact, repair or replace if necessary.
End of test

NO
Voltage supply of component B50 (Fuel temperature sensor)
Figure legend

- B50 (Fuel temperature sensor)
- Y94 (Quantity control valve)
Special tool

- Adapter cable220 589 00 99 34
Test sequence

- Switch off ignition.
- Detach coupling at component B50 (Fuel temperature sensor).
- Connect adapter cable no. 220 589 00 99 34 to engine wiring harness B50 (Fuel temperature sensor).
- Measure direct voltage with multimeter between sockets (B50x1) 2 and (B50x1) 1
- Switch on ignition.
Specified value

- Voltage[3.1...3.5] V
Question

- Is the measurement value OK?







YES
Check internal resistance of component B50 (Fuel temperature sensor).
Figure legend

- B50 (Fuel temperature sensor)
- Y94 (Quantity control valve)
Special tool

- Adapter cable220 589 00 99 34
Test prerequisite

- The actual value is not o.k.
Test sequence

- Switch off ignition.
- Connect adapter cable no. 220 589 00 99 34 at component B50 (Fuel temperature sensor).
- Test resistance.
- Measure resistance with multimeter between sockets (B50) 2 and (B50) 1
Specified value

- Resistor[20° C]: [2963...3210]ohms
- Resistor[30° C]: [1918...2078]ohms
- Resistor[40° C]: [1274...1380]ohms
- Resistor[50° C]: [866...938]ohms
- Resistor[60° C]: [605...649]ohms
- Resistor[90° C]: [227...241]ohms
Question

- Is the measurement value OK?







YES
The measurement value is OK.Further procedure

- Test signal line between components N3/9 (CDI control unit) and B50 (Fuel temperature sensor) for Open circuit.
End of test

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

- Replace component B50 (Fuel temperature sensor).
End of test

NO
The measurement value is not OK.Further procedure

- Test lines between components N3/9 (CDI control unit) and B50 (Fuel temperature sensor) for Open circuit.
End of test