Faulty Signal. Permanent Fault

Faulty signal. Permanent fault

Checking connectors








- Ignition off
- Check the connector for seat heater module connector A and the (30-pin) control module connector. Check for contact resistance and oxidation. Remedy if necessary.
Check for damage carefully
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Wait at least three minutes so that the control module has time to carry out its diagnostic
- Read off diagnostic trouble codes (DTCs).
The fault is no longer present if the status of the diagnostic trouble code (DTC) has changed to intermittent.

Other information:
- To remove the control module, see Comfort module Removal and Replacement
- To access and replace the seat heater module, see Seat heater module, replacing Front Seat, Driver's Seat, Front Seat
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault









Has the status of the diagnostic trouble code (DTC) changed to intermittent?

Yes - FAULT FOUND

No - Checking the cable

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Checking the cable
Check the signal cable between climate control module terminal #A9 and connector terminal A#2 on the left seat heater module. Check for an open-circuit. Check for a short-circuit to ground.

Note! If the seat heater is activated at high or low level, the signal in the cable is pulsed in pulse trains between approximately 0 V and battery voltage.

Check that the power supply to the seat heater module is OK between connector terminals A#1 (ground) and A#4 (battery voltage). The ignition must be on during this check.
For further information about the circuit before the seat heater module, refer to the "Wiring diagrams" Service Manual. Try a new seat heater module if the signal and power supply is OK.
Remedy as necessary.

Other information:
- To access and replace the seat heater module, see Seat heater module, replacing Front Seat, Driver's Seat, Front Seat
- To connect the breakout box, see Connecting the breakout box, climate control module Connecting The Breakout Box
- For the voltage of the signal cable, see Climate control signal specifications Signal Specification
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault














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
- Wait at least three minutes so that the control module has time to carry out its diagnostic
- Read off diagnostic trouble codes (DTCs).
The fault has been remedied if the status of the diagnostic trouble code (DTC) has changed to intermittent.





Has the status of the diagnostic trouble code (DTC) changed to intermittent?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - FAULT FOUND

VERIFICATION FAILED - 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 connectors

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