P06C6
Cylinder 2 Glow Plug Incorrect
Glow plugs (diesel)
Generic OBD-II
High
What it means
P06C6 is a diesel code meaning the glow plug on cylinder 2 is reading incorrectly — often the wrong plug fitted, or one that's failing and returning out-of-spec resistance. Glow plugs pre-heat the cylinder for cold starting, so the symptoms are hard cold starts, rough cold running, and extra exhaust smoke until it's corrected.
High
Can I keep driving? Drivable once warm, but expect hard cold starts and rough cold running until the glow plug is corrected.
Common symptoms
What you'll notice
- Hard starting when the engine is cold
- Rough running and shaking for the first minute after a cold start
- White or grey smoke from the exhaust on cold start-up
- Check-engine (or glow plug) light on
Common causes
Most likely first
- Wrong or out-of-spec glow plug fitted to cylinder 2Likely
- Failed cylinder 2 glow plug reading incorrect resistanceCommon
- Wiring or connector fault altering the cylinder 2 signalCommon
- Faulty glow plug control moduleLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the fault is specific to cylinder 2.
- Check that the correct glow plug part is fitted — a mismatched plug is a common trigger for 'incorrect' faults.
- Measure the cylinder 2 glow plug resistance and compare it with the other plugs.
- Inspect the wiring and connector for corrosion or damage.
- Replace the glow plug with the correct part, or test the control module if all plugs check out. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P06C6?+
Yes, once warm it drives normally. The main effect is hard cold starting and rough cold idle, which is worse in cold weather.
Can I just clear P06C6?+
It will return until the correct, working glow plug is fitted to cylinder 2. Clearing it alone does not fix the fault.
Related codes
Often seen with P06C6
Read & clear P06C6 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX