P0683Glow Plug Control Module 1 to PCM Communication Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Glow plug module 1 reports to the engine module over a feedback wire (Bosch-type systems expect it inverse to the activation line) or the bus; GM and Ford report a lost bus link as U0106, Saab as P0380/P1380, and no manufacturer document available to us uses P0683/P0684 themselves. P0683 means communication or feedback from the glow module to the engine module is missing or the line is open or shorted. The engine module then no longer receives plug status reports, so the individual plug monitoring fails; depending on design the glow module keeps glowing on its own timing or not at all. The activation line in the other direction is P0670/P0383/P0384.
- What you may notice
- Check engine light (glow plug lamp may flash or stay on)
- Harder cold start, long cranking in frost
- Rough running and white smoke after a cold start
- No individual plug reports any more
- Likely causes
- LikelyCommunication or feedback wire between glow and engine module open, chafed or connector corroded
- PossibleGlow module without supply or ground (fuse, main cable) – does not answer
- PossibleGlow module faulty internally
- RareGlow or engine module software or programming
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.