OBD-II code · Powertrain (generic, extended)
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.
Is it safe to drive with P256C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySwitch wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Check engine light on
- Idle speed too high, too low, or unstable
- Possible stalling at idle or after cold start
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Idle Speed Selector Switch
Related codes
- P256AEngine Idle Speed Selector Sensor/Switch Circuit/Open
- P2569Direct Ozone Reduction Catalyst Temperature Sensor Circuit Low
- P256BEngine Idle Speed Selector Sensor/Switch Range/Performance
- P256DEngine Idle Speed Selector Sensor/Switch Circuit High
- P256EEngine Idle Speed Selector Sensor/Switch Circuit Intermittent/Erratic
- P256FA/C Request B Circuit Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.