Signal Too Low
Signal too low
Checking components and wiring
- Ignition on.
Check the sun sensor by varying the light intensity. Cover the sun sensor with your hand for example to obtain the minimum signal value, approximately 0 W/m2.
Then aim a strong light source (for example a flashlight) at the sun sensor from close range to increase the signal.
Click on the VCT2000 symbol to read off the sun intensity.
Note! The illustration only shows the method. The appearance of the sun sensor can vary between different models.
Does the value change?
Yes - Checking the cable
No - Checking components and wiring
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Checking components and wiring
Check the signal cable between control module terminal #B4 (#4) and sun sensor terminal #1 (#21). Check for a short-circuit to ground.
Try replacing the sun sensor if no fault is found in the wiring.
Remedy as necessary.
Other information:
- To access or replace the control module, see Climate control module (CCM), replacing Service and Repair
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access or replace the sun sensor, see Sun sensor / alarm LED, replacing Service and Repair
- For other values, see Signal description, climate control module (CCM), Connector B Signal Description, Climate Control Module (CCM), Connector B
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Verification
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Checking the cable
Check the cable between the control module terminal #B4 (#4) and sun sensor terminal #1 (#21). Check for an intermittent short-circuit to ground.
Remedy as necessary.
Other information:
- To access or replace the control module, see Climate control module (CCM), replacing Service and Repair
- To connect the breakout box, see Connecting the breakout box Connecting the Breakout Box, Climate Control Module (CCM)
- To access or replace the sun sensor, see Sun sensor / alarm LED, replacing Service and Repair
- For other values, see Signal description, climate control module (CCM), Connector B Signal Description, Climate Control Module (CCM), Connector B
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Verification
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Verification
Hint: After the repair it is necessary to check that the fault has been rectified.
- Ignition off.
- Connect the connectors, install the components, etc.
- Ignition on.
Check solar input signal by varying light intensity on solar sensor. Cover solar sensor, for example with hand, to get minimum signal. Shine, for example, a powerful torch close to the solar sensor to get a maximum signal.
The value should vary between approximately 0 and 1000 W/m2.
Is the value 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 - No Fault Found
Attempt New Test - Checking components and wiring
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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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FAULT FOUND - Fault Found
Attempt New Test - Checking components and wiring
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