Signal Too Low

Signal too low

Checking the supply
Check the power supply to combustion preheater module (CPM) terminal #9. Check for contact resistance and oxidation. Check for loose connections. Also check the fuse in the engine compartment. Voltage should be 12 V.
Check the cable between terminal #1 on the Ext-X relay (2/29) and terminal #15 on the combustion preheater module (CPM). Check for contact resistance and oxidation. Check for loose connections. Check the relay, the power supply to the relay and the passenger compartment fuse.
If no fault is found, the fault may have been intermittent.
Remedy as necessary.

Other information
- Checking wiring and terminals Checking Wiring And Terminals





Continue - Verification

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Verification




Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off
- Reinstall the connectors, components etc.
- Ignition on.
Activate the combustion preheater module (CPM).
Check that the engine coolant heater is activated.

Is the engine coolant heater working?

Yes - Verification completed

No - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit Fault-Tracing

No - Attempt New Test

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Attempt New Test - Checking the supply

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