Signal Too Low

Signal too low

Checking the component




- Ignition on.
If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can be caused by interference at start up of the central electronic module (CEM) or may be a different type of fault which occurs on different occasions. The fault is evaluated depending on how it occurs.
Vary the light intensity. Read off the signal from the sun sensor.
Cover the sun sensor with your hand to obtain the minimum signal, approximately 0.5 volts.
Then direct a strong light source (for example a flashlight) at the sun sensor from close range to increase the signal.

Hint: The value must vary between approximately 0.5 and 4.85 V.

Note! The illustration only shows the method. The appearance of the sun sensor can vary between different models.









Is the function OK?

Yes - DONE

No - Checking the wiring

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Checking the wiring




- Ignition off.
Check the wiring between the central electronic module (CEM) and sun sensor. Check for contract resistance and oxidation. Check for damage.
Check the wiring between the central electronic module (CEM) and the sun sensor. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) terminal #D30 (#30) and sun sensor terminal #1
- Central electronic module (CEM) terminal #D42 (#42) and sun sensor terminal #5.
Replace the sun sensor if no fault is found in the wiring.
Remedy as necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Signal specification Pinout Values and Diagnostic Parameters
- Sun sensor / alarm LED, replacing Service and Repair
- Central electronic module (CEM), replacing Central Electronic Module (CEM), Replacing
- Checking wiring and terminals Checking Wiring And Terminals






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.
Check the signal from the sun sensor by varying the light intensity at the sun sensor. Cover the sun sensor with your hand to obtain a minimal signal. Then direct a strong light source (for example a flashlight) at the sun sensor from close range to obtain a maximum signal.
The value must vary between approximately 0.5 and 4.85 V.









Is the function OK?

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 - FAULT-TRACING FAILED

No - Attempt New Test

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FAULT-TRACING FAILED - FAULT-TRACING FAILED

Attempt New Test - Checking the wiring

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