Powertrain
generic / SAE
P256C
Engine Idle Speed Selector Sensor/Switch Circuit Low
Idle-speed selector input reads stuck low — short to ground or analog signal at minimum. 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.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 6C
Possible causes
- Switch wire shorted to ground high
- Connector pins corroded - high contact resistance low
- Harness chafing through insulation low
Symptoms
- Check engine light on
- Idle speed too high, too low, or unstable
- Possible stalling at idle or after cold start
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 60–350 €
- Estimated time: 0.3–1.5 h
- Component: idle speed selector switch
- MIL / check engine light
Sources
References
sae:J2012