P069DCylinder 10 Glow Plug Control Circuit High
- 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
- Modern diesel glow systems switch each glow plug through its own power semiconductor (in a glow plug module or the engine module), so current and faults can be measured per plug; a faulty channel is switched off. CARB requires glow plugs to be checked for correct current and voltage drop and, since model year 2010, a single plug outside specification to be detected and named. P069D means the circuit to the cylinder 10 glow plug is shorted to battery voltage, so the driver cannot switch it off. GM's engine-module drivers detect an impedance to the supply below 0.5 Ω (0.14 Ω for low-resistance plugs) in 10 of 20 samples, lamps after two trips; Ford's 2023 Power Stroke sees 0 A in its measuring path while the plug is commanded on. A permanently powered plug can overheat and burn through. No manufacturer document available to us uses this code for cylinders 9 and above; the description follows cylinders 1–8.
- What you may notice
- Check engine and glow plug lamp
- Plug permanently powered, possible battery drain
- Plug burns through, then an open-circuit code
- Likely causes
- LikelyCylinder 10 plug wire touching battery positive (chafing in the harness)
- PossibleMoisture or corrosion in the module or plug connector
- PossibleDriver in the glow or engine module shorted (permanently on)
- RareGlow module software (GM bulletins)
- 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: €60 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.