Cause
Blown fuse supplying the glow plug circuit
The fuse or fusible link feeding the glow plug system, blown so no heating occurs at all. Glow plug circuits carry very high current — often over a hundred amps across a bank of plugs — so they are protected by a heavy fuse or link rather than a blade fuse, and that protection is doing a real job.
A blown fuse is a symptom, and replacing it without asking why is the mistake. These fuses do not fail from age; they fail because a plug has shorted internally, a supply cable has chafed to earth, or the control module's output stage has failed short. Fitting a new fuse to a shorted plug blows it again immediately, and repeatedly doing so damages the wiring the fuse exists to protect.
Measure each plug's resistance before replacing the fuse. A healthy plug reads well under two ohms; a shorted one reads near zero and is the outlier in the set. The complaint is a hard cold start with white smoke and no fault when warm, since the circuit is only used below a temperature threshold — which is also why the fault seems to disappear for the summer.
Typically an easy fix. Often worth checking before paying anyone to look.
Codes this can cause (4)
Codes where this is a likely explanation first, rather than merely a possible one.
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Others who found this
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Blown fuse supplying the glow plug circuit.