P064C
Glow Plug Control Module 1
Glow plugs (diesel)
Generic OBD-II
Medium
What it means
P064C means the diesel glow-plug control module has a fault — the module that powers the glow plugs to preheat the cylinders for cold starting. The engine typically runs fine once warm, but cold starts can be difficult, rough, or produce white smoke until the glow-plug system is repaired.
Medium
Can I keep driving? The engine still runs once warm, but cold starts may be hard, rough, or smoky until it's fixed — get it checked, especially before cold weather.
Common symptoms
What you'll notice
- Check-engine light, often with a glow-plug or wait-to-start light
- Hard starting when cold
- Rough running or white smoke on a cold start
- Reduced cold-weather performance
Common causes
Most likely first
- Faulty glow-plug control moduleLikely
- Damaged wiring or connectors at the moduleCommon
- Failed glow plug(s) loading the moduleCommon
- Faulty ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Scan for companion glow-plug circuit codes.
- Check the control module's power, ground, and connectors.
- Measure each glow plug's resistance and replace any that read open.
- Replace the glow-plug control module if it fails its self-check.
- Clear the code and verify a normal cold start.
FAQ
Quick answers
Is it safe to drive with P064C?+
The engine runs once warm, but cold starts can be hard, rough, or smoky. Get it checked, especially before winter.
Can I just clear P064C?+
It returns until the glow-plug control module or the affected plugs are repaired.
Related codes
Often seen with P064C
Read & clear P064C 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