U019CLost Communication 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
- U019C points to a second glow plug control module, needed where a diesel has more preheating channels than one unit drives, for example one module per cylinder bank. No manufacturer documents U019C publicly; it is absent from GM's diesel tables and from the NHTSA bulletin index. The partner code U0106 for module 1 shows the logic: GM's 2015 engine diagnostics table fails it when no GPCM frame has arrived for more than 0.25 s during a 10 s test and rates it Type B. CARB requires glow plugs to be checked for correct current and response to commands, which presumes a live link to the module. The plugs on the affected side may stay cold, giving hard cold starts, rough running and white smoke while warming up; an MIL is to be expected. U049D is invalid data.
- What you may notice
- Hard starting when cold
- White smoke and rough idle until warm
- Preheat lamp behaves oddly, MIL on
- Likely causes
- LikelyGlow plug module 2 without supply, ground or ignition feed
- PossibleWater or corrosion in the module connector near the engine
- PossibleBus line to module 2 chafed or connector loose
- RareGlow plug control module 2 faulty
- 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: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.