U0106Lost Communication With Glow Plug Control Module 1
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- U0106 reports that glow plug control module 1 of a diesel engine no longer communicates. In Ford's 2023 diesel summary (6.7 L and 3.0 L) the GPCM is declared lost after 5 s of silence. GM's 2015 Cruze diesel table fails it when no GPCM message arrives for 0.25 s over a 10 s test (Type B); GM's 2018 diesel table also lets the GPCM report that it misses ECM frames $C9, $4C1 or $4F1 and sets U0106 after 11 s as Type B over two trips. Isuzu's N-Series bulletin SB18-N-001A (4HK1, 2011–2018) links the MIL with U0106 to water running down the glow plug harness into the GPCM plug; sealed terminals fix it. Expect hard cold starts, white smoke and an unreliable wait-to-start lamp.
- What you may notice
- MIL on
- Long cranking or no start when cold
- White smoke after cold start
- Wait-to-start lamp behaves oddly
- Likely causes
- LikelyWater or corrosion in the glow plug module connector or harness
- PossibleModule supply fuse, relay or ground faulty
- PossibleDamaged CAN lines to the glow plug module
- RareGlow plug module internally faulty (overtemperature, driver)
- 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: €40 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.