Checking the Rear Fog Lamp

Checking the rear fog lamp

Checking the signal from the switch for the rear fog lamp




- Ignition on.
Turn the lighting switch to position 2 and activate the switch for the rear fog lamps. Read off the signal from the switch for the rear fog lamps. The value must be On.





Is the value On?

Yes - Checking wiring and components

No - Checking wiring and components

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Checking wiring and components




- Ignition off.
Check that fuse 18 the integrated relay / fusebox in the engine compartment is intact.
Check the cable between control module connector F #11 (#B11) and fuse 18 and the cable between control module connector P #6 (#B26) and lighting switch #10 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault , contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault and for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Check the cable between control module connector P #5 (#B25) and left and right parking lamp #1 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Try a new switch if no fault is found in the cables.
Remedy as necessary.

Other information
- To connect the breakout box, see Connecting the breakout box Connecting The Breakout Box. Central Electronic Module (CEM).
- For information about signals, see Signal specification Signal Description. Central Electronic Module (CEM).
- To access / replace the switch see Replacing rocker switch Removal and Replacement.













Continue - Verification

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Checking wiring and components




- Ignition off.
Check that the bulbs for the rear fog lamp are intact.
Check the cable between the switch for the fog lamp # 13 and control module connector P #4 (#B24) and the cables between control module connector B1 #11 (#A41) and the left and right fog lamp #2.1 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault , contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault and for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Check the ground cables from each fog lamp for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault , contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring And Terminals. Permanent Fault.
Remedy as necessary.

Other information
- To connect the breakout box, see Connecting the breakout box Connecting The Breakout Box. Central Electronic Module (CEM).
- For information about signals, see Signal specification Signal Description. Central Electronic Module (CEM).









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 rear fog lamp. The rear fog lamp must both light and go out.





Does the rear fog lamp light and go out?

Yes - VERIFIED

No - VERIFICATION FAILED

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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 - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking the signal from the switch for the rear fog lamp

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