What does the Glow plug light (diesel) mean?

At start-up: the glow plugs are warming the cylinders — wait for it to go out before cranking. While driving, or flashing: a glow plug or engine management fault.

How much does it cost to fix the Glow plug light (diesel)?

Typically $80 to $500 in the US, depending on the cause. A glow plug set or relay.

Glow plug light (diesel): meaning, urgency, cost

Urgency:Service soon

Is it safe to keep driving?

Yes if it is steady after start-up. A flashing glow plug light on many diesels signals an engine fault and reduced power; have it read soon.

Likely causes

Normal pre-heat (steady, goes out in seconds)
Failed glow plug or relay
Engine management fault (flashing)

Typical repair cost (US)

$80 – $500

A glow plug set or relay.

A typical range, not a quote. Actual cost depends on the car, the shop and the fault.

What to do now

Wait for the light to go out before starting when cold.
If it flashes while driving, have the fault code read.

Read the full guide →Check your VIN for open recalls →All warning lights