2005 Nissan P0505: What It Means & Is It Safe to Drive?
P0505 on the 2005 Nissan: Idle Air Control System Malfunction. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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 on the 2005 Nissan
- 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
For a 2005 Nissan, repairs for P0505 typically fall between $80 and $350, depending on the root cause and labor rates in your area.
Known issues on Nissan
Nissan P0505 on VQ35 and QR25 engines with IACV systems is most often a dirty idle air control valve. Nissan IACV units are prone to carbon buildup—cleaning with aerosol throttle body cleaner usually restores normal idle before a replacement is needed.
Most commonly affected models