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OBD-II · Engine and powertrain (P)

P0383

Glow plug control module control circuit low

What it means

The glow-plug control module control circuit has a low-level electrical fault. The monitored circuit and detection criteria depend on the vehicle, so this does not automatically identify the command wire from the engine computer.

Symptoms

  • harder starting when cold
  • rough running and white smoke for the first moments after a cold start
  • glow plug light may flash
  • possibly no symptoms in warm weather

Likely causes, most likely first

Likely causes, most likely first
No.Cause
01module power-supply or engine/module ground fault
02control-circuit wiring or connector fault
03failed glow-plug control module

What to check, step by step

  1. 01Identify the monitored circuit and full fault details in the vehicle-specific service information.
  2. 02Check module supply and engine/module grounds under load.
  3. 03Inspect connectors and test the identified control circuit for opens or shorts.
  4. 04Replace the module only after supply, grounding and wiring faults have been excluded.