P069C
Cylinder 10 Glow Plug Control Circuit Low
Glow plugs (diesel)
Generic OBD-II
High
What it means
P069C is a diesel code meaning the glow plug control circuit for cylinder 10 read an abnormally low voltage — usually a short to ground or a failed plug. Glow plugs pre-heat the cylinder for cold starting, so the main symptoms are hard cold starts, rough cold running, and extra exhaust smoke until the engine warms.
High
Can I keep driving? Drivable once warm, but expect hard cold starts and rough cold running until the glow plug circuit is repaired.
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
- Failed glow plug on cylinder 10Likely
- Short-to-ground or open in the cylinder 10 glow plug wiringCommon
- Corroded or loose glow plug connectorCommon
- 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 10's control circuit.
- Inspect the wiring and connector to the cylinder 10 glow plug for a short to ground or an open.
- Measure the cylinder 10 glow plug resistance and compare it to the other plugs.
- Replace the glow plug or repair the wiring as needed.
- If the plug and wiring are good, test the glow plug control module. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P069C?+
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 P069C?+
It will return until the glow plug or its control-circuit wiring is fixed. Clearing it alone does not repair the fault.
Related codes
Often seen with P069C
Read & clear P069C 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