What are the symptoms of P0380?

Common symptoms include: Hard cold starts; White smoke on cold start; Rough running until warm.

What causes a P0380 code?

The most common causes are: Failed glow plug(s); Glow plug control module; Relay or wiring fault.

How do you fix P0380?

Test each glow plug's resistance; Check the glow-plug module/relay; Inspect the harness and connectors. Worth diagnosing soon — left alone, the underlying issue can grow into a bigger, costlier problem.

OBD-II Code Lookup

P0380Watch

Glow Plug/Heater Circuit 'A' Malfunction

Cold Start system

A fault in the glow-plug heating circuit. Glow plugs preheat the cylinders for cold starting, so a fault shows up most in cold weather.

Worth diagnosing soon — left alone, the underlying issue can grow into a bigger, costlier problem.

Common symptoms

Hard cold starts
White smoke on cold start
Rough running until warm

Common causes

Failed glow plug(s)
Glow plug control module
Relay or wiring fault

How it's diagnosed & fixed

Test each glow plug's resistance
Check the glow-plug module/relay
Inspect the harness and connectors

Got P0380? Get it diagnosed.

A real technician can interpret P0380 in the context of your truck and symptoms — and tell you what's actually wrong before you buy parts.

Find a Specialist

Related Cold Start codes

P0540Intake Air Heater Circuit P0670Glow Plug Module Control Circuit P0683Glow Plug Module to ECM Communication Circuit

Reference only. A trouble code names a symptom, not the failed part — always confirm with a live diagnosis before repairs. See our Knowledge Base for deeper guides.