OBD-II code · Powertrain (generic)
P066C Cylinder 2 Glow Plug Control Circuit Low
The control line for the glow plug on cylinder 2 is shorted to ground or the plug is internally shorted.
Is it safe to drive with P066C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyControl line shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.4 h
- Emissions test
- Likely to fail
- Parts involved
- Glow Plug Cyl 2
Related codes
- P066ACylinder 1 Glow Plug Control Circuit Low
- P066ECylinder 3 Glow Plug Control Circuit Low
- P067ACylinder 4 Glow Plug Control Circuit Low
- P067CCylinder 5 Glow Plug Control Circuit Low
- P067ECylinder 6 Glow Plug Control Circuit Low
- P068CCylinder 7 Glow Plug Control Circuit Low
- P068ECylinder 8 Glow Plug Control Circuit Low
- P069ACylinder 9 Glow Plug Control Circuit Low
- P069CCylinder 10 Glow Plug Control Circuit Low
- P06E0Cylinder 11 Glow Plug Control Circuit Low
- P06E2Cylinder 12 Glow Plug Control Circuit Low
- P0669Control Module Internal Temperature Sensor A Circuit High
- P066BCylinder 1 Glow Plug Control Circuit High
- P066DCylinder 2 Glow Plug Control Circuit High
- P066FCylinder 3 Glow Plug Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.