OBD-II code · Network

U0106 Lost Communication with Glow Plug Control Module

The Glow Plug Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Cold-start pre-heating is no longer coordinated, causing hard diesel starts. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.

Is it safe to drive with U0106?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyGlow plug module unpowered
  • PossibleCAN wiring to glow plug module broken
  • Less likelyGateway module routing CAN messages incorrectly

Symptoms

  • Multiple warning lights may illuminate
  • Affected modules may go into limp mode or shut down
  • Specific functions inoperative depending on module
  • Diagnostic tools may show communication faults

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–4 h
Emissions test
Likely to fail
Parts involved
Glow Plug Control Module, Can Bus Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.