What does code P0505 mean and is it safe to drive?
P0505: Idle Air Control System Malfunction. Here’s what it means, what usually causes it, what repairs typically cost, and how urgent it is to keep driving.
PowertrainGenerally safe to drive
Repair cost
$80–$350
System
Powertrain
Urgency
medium
What this code means
The idle air control (IAC) system is not maintaining idle speed within the expected range. This code appears on older vehicles with a separate IAC valve; on drive-by-wire systems a similar issue triggers P0507 or P0506.
Common causes
- Dirty or failed idle air control valve
- Vacuum leaks affecting idle circuit
- Throttle body carbon buildup
- Faulty IAC motor or wiring
Symptoms
- Check Engine Light
- High, low, or fluctuating idle
- Stalling at stops
- Hard starting when warm
Typical fixes
- Clean or replace idle air control valve
- Clean throttle body
- Check for vacuum leaks
- Inspect IAC wiring and connector
Repair cost range
Repairs for P0505 often fall between $80 and $350, depending on the cause and your vehicle.