OBD-II code · Powertrain (generic)
P0683 Glow Plug Control Module 1 to PCM Communication Circuit
Glow Plug Control Module 1 to PCM Communication Circuit: an electrical fault is present in the circuit. This affects diesel cold-start preheating.
Is it safe to drive with P0683?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen or short on communication wire
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Glow Plug Control Module 1, Gpcm Communication Wire
Related codes
- P06FCGlow Plug Control Module 2 to PCM Communication Circuit
- P0680Cylinder 10 Glow Plug Circuit Open
- P0681Cylinder 11 Glow Plug Circuit Open
- P0682Cylinder 12 Glow Plug Circuit Open
- P0684Glow Plug Control Module 1 to PCM Communication Range or Performance
- P0685ECM or PCM Power Relay Control Circuit Open
- P0686ECM/PCM Power Relay Control Circuit Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.