Signal Too Low.

Signal too low.

Checking the status




- Ignition on
- Light switch in position 1 or position 2.
Check the voltage level from the light switch module (LSM).
Check if the fault is permanent or intermittent.
The voltage level must be changed when the instrument lighting control is altered.
The fault is permanent if the voltage level does not change.
If the voltage level changes, 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.
Click on the VCT2000 symbol to read off the voltage level.









Does the value change?

Yes - Verification

No - Checking the component and wiring

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Checking the component and wiring
Check the signal cable. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) terminal #B21 (#21) and light switch module (LSM) terminal #9.
Remedy as necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)

- 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.
Read off the rheostat signal by clicking the VCT2000 symbol.
Check that the value changes when the instrument lighting control changes.





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

Attempt New Test - Checking the component and wiring

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