Powertrain
generic / SAE
P0505
Idle Air Control System Malfunction
A general fault has been detected in the idle air control (IAC) system. On older vehicles with a separate IAC valve, this means the valve cannot maintain commanded idle RPM; on drive-by-wire systems, the equivalent fault is in the throttle body's idle adaptation.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number5 / 05
Possible causes
- IAC valve carboned, sticky high
- Throttle body dirty (drive-by-wire) medium
- Vacuum leak affecting idle medium
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: 30–400 €
- Estimated time: 0.3–2.5 h
- Component: idle air control valve
- Component: throttle body
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012