OBD-II code · Powertrain (generic)
P0380 Glow Plug/Heater Circuit "A" Malfunction
The glow plug control module reports an electrical fault on circuit A — typically a single glow plug open-circuit, the relay failing, or wiring to the harness damaged. Diesel-specific; affects cold-start behaviour.
Is it safe to drive with P0380?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOne or more glow plugs open-circuit
- PossibleGlow plug relay failed
- Less likelyWiring/harness damage
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
- Often, with basic tools
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Glow Plug, Glow Plug Relay, Glow Plug Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.