U030BSoftware Incompatibility With Glow Plug Control Module 2
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- U030B is the counterpart of U0307 for a second glow plug control module, used where an engine splits its glow plugs between two drivers, say one per bank. It is stored when the engine controller rejects the software or calibration identity of module 2, typically after only one of the two units was replaced or flashed. No manufacturer documents U030B publicly. A GM patent explains the dialogue behind it: glow plug faults are judged from several messages passed between engine and glow controller, with a strategy that changes with how long the plugs have been on in a drive cycle. GM also asks for the glow module software to be brought up to date after glow plug work (PIP5524). CARB requires glow plugs to be checked for proper response. U019C stands for lost contact, U049D for invalid data. Cold starts suffer; a MIL is likely.
- What you may notice
- Hard cold start, uneven running until warm
- White smoke after starting in the cold
- MIL and glow plug warning on
- Likely causes
- LikelyOnly glow module 2 (or only module 1) replaced, software levels now differ
- PossibleModule of another part number or engine variant installed in position 2
- PossibleEngine controller updated without the second glow module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · 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.