Faulty Signal

Faulty signal

Checking the function of the glow plug




- Ignition on (with additional heater start the engine).

Note! On cars where the heater functions as a parking heater there is no +15 voltage supply to the control module. The heater is activated using the timer stop and start buttons instead of VIDA vehicle communication. Individual components and functions cannot be activated when the +15 voltage supply is absent.

- Activate the heater.
Check the function of the heater according to Test running the additional heater / parking heater Initial Inspection and Diagnostic Overview.





Does the heater operate?

Yes - Intermittent fault

No - Checking the connectors

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Checking the connectors








- Ignition off
- Check the glow plug electrical terminal and control module connector. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Check for damage carefully
- Reinstall the components, reconnect the connectors etc.
- Ignition on (with additional heater start the engine).

Note! On cars where the heater functions as a parking heater there is no +15 voltage supply to the control module. The heater is activated using the timer stop and start buttons instead of VIDA vehicle communication. Individual components and functions cannot be activated when the +15 voltage supply is absent.

- Activate the heater.
Check that the heater starts and runs.
If the heater now functions, the cause of the fault was loose connections in the connectors.

Other information:
- To access the control module or connect the breakout box,
- To access the glow plug, see Outside temperature sensor and glow plugs, replace Replacing Outside Temperature Sensor And Glow Plugs.





Does the heater operate?

Yes - FAULT FOUND

No - Checking components and wiring

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Checking components and wiring
Check the cable between control module terminal #1 and the glow plug terminal. Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Replace the glow plug if no fault is found in the cable.
Remedy as necessary.

Other information:
- To access the control module or connect the breakout box,
- To access the glow plug, see Outside temperature sensor and glow plugs, replace Replacing Outside Temperature Sensor And Glow Plugs
- With the ignition on and the glow plug electrical terminal disconnected, the voltage between the glow plug electrical terminal (control module side) and ground must be approximately 9 V
- For other values, see Signal specification Additional heater 912-D/B Signal Specification Additional Heater 912-D/B.













Select Continue.

Continue - Verification

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Verification




Verification

Verification

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








- Ignition off
- Reinstall the connectors, components etc.
- Ignition on (with additional heater start the engine).

Note! On cars where the heater functions as a parking heater there is no +15 voltage supply to the control module. The heater is activated using the timer stop and start buttons instead of VIDA vehicle communication. Individual components and functions cannot be activated when the +15 voltage supply is absent.

- Activate the heater.
Check the function of the heater according to Test running the additional heater / parking heater Initial Inspection and Diagnostic Overview.





Does the heater operate?

Yes - VERIFIED

No - VERIFICATION FAILEDPAPER

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - FAULT FOUND

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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 - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the function of the glow plug

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Intermittent fault
Check the control module connector and the electrical terminal for the glow plug. Check for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults. Check for contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults
Check the cable between control module terminal #1 and the glow plug terminal. Check for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults. Check for an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults. Check for an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults.
Remedy as necessary.

Other information:
- To access the control module or connect the breakout box,
- To access the glow plug, see Outside temperature sensor and glow plugs, replace Replacing Outside Temperature Sensor And Glow Plugs
- With the ignition on and the glow plug electrical terminal disconnected, the voltage between the glow plug electrical terminal (control module side) and ground must be approximately 9 V
- For other values, see Signal specification Additional heater 912-D/B Signal Specification Additional Heater 912-D/B.













Select Continue.

Continue - Fault-tracing information
DONE

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Fault-tracing information




Information

Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

Do you want to view the information again?

Yes - Attempt New Test

No - FAULT FOUND

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Attempt New Test - Checking the function of the glow plug

DONE - DONE

FAULT FOUND - FAULT FOUND

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