P0683moderate severityPowertrain
Glow Plug Control Module to PCM Communication Circuit
on 2011 Audi Q7 3.0L Supercharged V6 · AWD
What this code means
The PCM has detected a communication fault between itself and the glow plug control module. This affects proper diesel cold-start glow plug operation.
Symptoms
- Hard cold starts
- Glow plug warning light on
- Rough idle when cold
Common causes
- Faulty wiring between PCM and glow plug module
- Corroded connectors
- Failed glow plug control module
- PCM fault
Diagnostic steps
- Scan for glow plug related codes
- Inspect wiring between PCM and module
- Check connector integrity and grounds
- Test glow plug control module
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