What does P0380 mean?

There is an electrical fault in glow plug circuit A.

Does P0380 only affect cold starts?

Mostly yes; once the engine is warm the glow plugs matter less.

Ignition and misfire

P0380 — Glow Plug/Heater Circuit A

The ECU detected a fault in glow plug circuit A on a diesel engine. Glow plugs heat the combustion chamber for cold starting, so starting and emissions are affected when the engine is cold.

Severity: Medium

This content is under review.

Common causes

Failed glow plug
Faulty glow plug relay or control module
Open or corroded wiring or connectors
Blown fuse
Low battery voltage

Symptoms

Hard starting in cold weather
White smoke on start-up
Rough running when cold
Glow plug warning light on, check engine light

How to check

Check the glow plug fuse and relay
Measure the resistance of each glow plug
Check wiring and the supply voltage at the plugs
Replace failed plugs and check the control module output

Can you keep driving?

Usually drivable once the engine has started, but cold starts become harder. Repair it before winter.

P0300
P0670

Frequently asked questions

What does P0380 mean?: There is an electrical fault in glow plug circuit A.
Does P0380 only affect cold starts?: Mostly yes; once the engine is warm the glow plugs matter less.

General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.