Powertrain
generic / SAE
P0518
Idle Air Control Circuit Intermittent
Same as P0511 with intermittent or erratic signal. 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
GroupP0
Range / number5 / 18
Possible causes
- Intermittent contact at connector high
- Connector with intermittent contact under vibration low
- Harness routed against vibrating component 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: easy
- DIY: possible
- Estimated cost: 80–320 €
- Estimated time: 0.4–1.5 h
- Component: idle air control valve
- Component: iac wiring
- MIL / check engine light
Sources
References
sae:J2012