Engine Idle Speed Selector Sensor/Switch Circuit Intermittent/Erratic
The idle-speed selector signal jumps or drops out — usually a worn rotary contact or vibration. 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
- Idle speed selector switch
Common causes
- High likelihood: Worn rotary contact
- Low likelihood: Connector with intermittent contact under vibration
- Low likelihood: Harness routed against vibrating component
Possible symptoms
- Check engine light on
- Idle speed too high, too low, or unstable
- Possible stalling at idle or after cold start
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
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.