Faulty Signal

Faulty signal

Checking the status




- Ignition on
- Light switch in position 2.
Activate the high beam.
Check if the fault is permanent or intermittent.
The fault is permanent if the high beam does not activate.
If the high beam is activated, this is an indication that the fault was present previously but that it is not active at the moment, i.e. the fault is intermittent.

Continue - Checking the component and wiring

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Checking the component and wiring




- Ignition off
- Light switch in position 0
- Disconnect connector A and connector B to the left-hand gas discharge lamp module (GDL)
- Disconnect the lamp housing connector.
Check the connectors for contact resistance and oxidation. Check for damage carefully.
Check the following signal cables between the left-hand gas discharge lamp module (GDL) and the left-hand lamp housing. Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Gas discharge lamp module (GDL) terminal #B3 and lamp housing terminal #2
- Gas discharge lamp module (GDL) terminal #B4 and lamp housing terminal #8.
Check the signal cable between the central electronic module (CEM) and the left-hand gas discharge lamp module (GDL). Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) terminal #E27 (#27) and gas discharge lamp module (GDL) terminal #A5.
Check the signal cable between the central electronic module (CEM) and the left-hand lamp housing. Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) terminal #E27 (#27) and lamp housing terminal #3.
Remedy as necessary.

Other information:
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Signal specification Signal Description, Central Electronic Module (CEM)
- Location of components Component Location, Central Electronic Module (CEM)
- Control module relay box passenger compartment Service and Repair
- Headlamp ballast (Xenon) Headlamp Ballast (Xenon)
- Checking wiring and terminals Checking Wiring and Terminals









Was a fault detected?

Yes - Verification

No - replacing

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Component, replacing




- Ignition off
- Light switch in position 0.
Replace the left-hand lamp housing.

Other information:
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Signal specification Signal Description, Central Electronic Module (CEM)
- Location of components Component Location, Central Electronic Module (CEM)
- Control module relay box passenger compartment Service and Repair
- Headlamp bulb (Xenon) Headlamp Bulb (Xenon)
- 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
- Light switch in position 2.
Switch between high and low beam.
Check that the function is OK.

Is the function OK?

Yes - Troubleshooting procedure complete

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 component and wiring

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