OBD-II code · Powertrain (generic)
P0508 Idle Air Control System Circuit Low
The control line to the idle air control valve - which opens a small bypass around the throttle to set idle airflow - is shorted to ground or measures a voltage below the plausible level.
Is it safe to drive with P0508?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyControl line shorted to ground
- PossibleIAC solenoid internally shorted
- Less likelyConnector pins corroded - high contact resistance
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.