Checking the supply circuit
- Ignition on.
There is a common power supply for the water pump, fuel pump (FP) and combustion fan. It is easier to locate the fault if the components are activated one at a time.
Activate the water pump, fuel pump (FP) and combustion fan. Use the smart tool.
WARNING:Do not activate the fuel pump (FP) for longer than a few seconds.
Check the circuit between control module terminal #11 and the components which are connected to the supply circuit (water pump terminal 2, fuel pump (FP) terminal 2 and combustion fan supply terminal). Check for an open-circuit. Check for a short-circuit to ground.
Remedy as necessary.
Other information:
- To access the control module or connect the breakout box, see Connecting the breakout box
- To access or replace the water pump, see Water pump engine coolant heater, replacing
- To access or replace the fuel pump (FP):
- For cars manufactured up to w38 2001 inclusive, see Fuel pump, auxiliary heater, replacing
- For cars manufactured from w39 2001 inclusive, see Fuel pump auxiliary heater, replacing .
- To access or replace combustion fan:
- For cars manufactured up to w38 2001 inclusive, see Fuel injection nozzle / fan motor / pressure equalizer, replacing
- For cars manufactured from w39 2001 inclusive, see Fuel injection nozzle / fan motor / pressure equalizer, replacing .
- For other values, see Signal specification
- See Checking wiring and terminals .
- Continue
Refer to Verification