P0384Glow Plug Control Module 1 Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P0384 is the counterpart of P0383: the control line from the engine module to the glow plug control module is too high, i.e. shorted to positive. In GM's logic for the 2010/11 Saab 9-5 2.0 TiD the signal terminal should show 9.5–10.5 V; a higher voltage for more than 0.5 s, with ignition on and 9–16 V, sets the code, there without check engine light. Ford's 2023 diesels (6.7 and 3.0 litre) use P0384 differently from the J2012 name, for the supply voltage of the glow plug module: below 6.5 V, above 16.5 V or open, detected in about 1 s – today J2012 has P052F for that. So with Ford, check battery, alternator and the module's supply first. The consequence is missing or irregular preheating or a protective shutdown of the module, with a poor cold start.
- What you may notice
- No or irregular preheating, hard starting when cold
- Smoke after a cold start
- Warning lamp depending on the manufacturer
- Likely causes
- LikelyControl line chafed against positive or bridged in the connector
- PossibleGlow plug control module faulty internally (feeding back)
- PossibleFord: supply of the module outside 6.5–16.5 V or open (battery, alternator, fuse)
- RareEngine module
- 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 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.