Signal Too Low

Signal too low

Checking the function




- Ignition on.
Check the sun sensor signal by varying the intensity of the light that it detects. Cover the sun sensor with your hand to obtain the minimum signal, approximately 0.5 volts.
Then aim a strong light source (for example a flashlight) at the sun sensor from close range to increase the signal.

Hint: If the signal from the sun sensor is a steady <0.25 volts, there is either a short-circuit to ground in the cable or the sun sensor is defective.

Click on the VCT2000 symbol to read off the sun sensor signal.









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

Does the value change?

Yes - Checking connectors and wiring

No - Checking the connector

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Checking the connector




- Ignition off
- Check the central electronic module (CEM) connector (terminals (#B5 (#5), #B28 (#28)) and the sun sensor connectors. Check for contact resistance. Check for oxidation. Check for damage carefully.

Other information
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Location of components Component Location, Central Electronic Module (CEM)
- Sun sensor Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals









Was a fault detected?

Yes - Verification

No - Checking the component and wiring

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Checking the component and wiring
Check the signal cable between central electronic module (CEM) terminal #B5 (#5) and sun sensor terminal #3. Check for an open-circuit. Check for a short-circuit to supply voltage.
Check the ground lead between central electronic module (CEM) terminal #B28 (#28) and sun sensor terminal #5. Check for an open-circuit. Check for a short-circuit to supply voltage.
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)
- Location of components Component Location, Central Electronic Module (CEM)
- Sun sensor Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals













Continue - Verification

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Checking connectors and wiring
Check the central electronic module (CEM) connector (terminals #B28, #B30) and the sun sensor connectors. Check for contact resistance. Check for oxidation. Check for damage carefully.
Check the signal cable between the central electronic module (CEM) terminal #B28 (#28) and sun sensor terminal #TBD (#TBD). Check for a short-circuit to ground.
Check the ground lead between the central electronic module (CEM) terminal #B30 (#30) and sun sensor terminal #TBD (#TBD). Check for a short-circuit to ground.

Other information
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Location of components Component Location, Central Electronic Module (CEM)
- Sun sensor Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals













Continue - Fault-tracing information

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









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

Attempt New Test - Checking the function

FAULT-TRACING FAILED - No Fault Found

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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

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