OBD-II code · Powertrain (generic)
P0671 Cylinder 1 Glow Plug Circuit
An electrical fault is present in the glow plug circuit for cylinder 1. The glow plug control module cannot drive this plug correctly — open circuit, short, or out-of-range resistance — so cylinder 1 is not pre-heated. On a cold start this causes hard starting, white smoke, and a misfire-like rough run until the engine warms. Causes: a failed glow plug, a broken supply lead to that plug, corrosion at the plug connector, or a faulty module output for cylinder 1.
Is it safe to drive with P0671?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyGlow plug element open
- PossibleWiring or connector fault
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Glow Plug, Glow Plug Wiring
Related codes
- P0670Glow Plug Module Control Circuit
- P0672Cylinder 2 Glow Plug Circuit
- P0673Cylinder 3 Glow Plug Circuit
- P0674Cylinder 4 Glow Plug Circuit
- P0675Cylinder 5 Glow Plug Circuit
- P0676Cylinder 6 Glow Plug Circuit
- P0677Cylinder 7 Glow Plug Circuit
- P0678Cylinder 8 Glow Plug Circuit
- P066ECylinder 3 Glow Plug Control Circuit Low
- P066FCylinder 3 Glow Plug Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.