Exhaust Aftertreatment Glow Plug Control Circuit High
Voltage on the aftertreatment glow plug control line is above the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Aftertreatment glow plug
- Relay
- Wiring harness
Common causes
- High likelihood: Control wire shorted to B+
- Medium likelihood: Open relay coil
- Low likelihood: Connector pins corroded - high contact resistance
Possible 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
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.