P06C1Cylinder 9 Glow Plug Circuit Range/Performance
- 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
- The glow module calculates each plug's resistance from voltage and current while glowing. 'Range/performance' means the circuit is electrically intact but the resistance or current lies outside the specified window – typically an aged, high-resistance or wrong plug or contact resistance at the connector. CARB requires a single plug outside specification to be detected from model year 2010. Ford's 2023 6.7 L/3.0 L Power Stroke runs this check during heating after the open and short checks and flags a circuit above 2 Ω after about 3 s. GM does not use this code family. No manufacturer document available to us uses this code for cylinders 9 and above; the description follows cylinders 1–8. P06C1 concerns the glow plug of cylinder 9 alone; the same plug's open circuit is P0679, its control circuit low and high P069A/P069B, and an incorrect plug fitted P06CD.
- What you may notice
- Check engine and glow plug lamp
- Harder cold start in frost
- Rough running and white smoke after a cold start
- Often no symptom when warm
- Likely causes
- LikelyGlow plug cylinder 9 aged or high-resistance
- PossibleContact resistance at plug connector or terminal nut
- PossibleWrong plug type or a plug with a manufacturing fault
- RareEngine or glow module software (Ram 6.7 L from 2025)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.