OBD-II code · Powertrain (generic)
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.
Is it safe to drive with P0518?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyIntermittent contact at connector
- Less likelyConnector with intermittent contact under vibration
- Less likelyHarness routed against vibrating component
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
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.4–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Idle Air Control Valve, Iac Wiring
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.