What it means
The glow plug control driver does not respond to commands within tolerance. Cold-start glow function is degraded so cold starting can be delayed and white smoke increases.
At a glance
- Usually lights the check-engine light
How it works
The glow plug control driver switches power to the diesel engine's glow plugs to help heat the combustion chambers for cold starting. P263C sets when the driver does not respond to commands within its expected performance limits, so glow plug heating can be reduced and cold starts may take longer.
Common causes
Most likely first.
- Aged driver shows degraded switching behaviour
- Current feedback loop noisy
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
How to diagnose it
- Save freeze-frame data and check whether the fault occurred during a cold start, when the glow plug driver is expected to operate.
- Scan for glow plug, module power, and cylinder-specific circuit codes that could identify an overloaded or misfiring part of the system.
- Inspect the glow plug driver's power, ground, connectors, and harness for looseness, corrosion, heat damage, or poor routing.
- Review available scan-tool data for the driver's command and current feedback to see whether switching is delayed, unstable, or absent.
- Test the driver and glow plug circuits using the manufacturer's procedure, checking for excessive load and noisy or implausible current feedback.
Common fixes
- Repair a loose, corroded, or heat-damaged driver connector.
- Repair damaged wiring or a poor driver ground.
- Replace a glow plug confirmed to be causing abnormal current draw.
- Replace the glow plug control driver after circuit and load tests confirm degraded switching.
Can I keep driving?
In mild weather the engine may still start, but cold starting can become difficult and unburned fuel may produce white smoke during warm-up. Avoid repeated long cranking, especially in cold conditions, and address the fault before relying on the vehicle for cold starts.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.