OBD-II code · Powertrain (generic)
P0511 Idle Air Control Circuit
A general circuit fault is detected on the idle air control valve - open or short on supply, signal or ground. The ECU loses control of idle bypass airflow.
Is it safe to drive with P0511?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in valve or wiring
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.