P1505 — Idle Air Control (IAC) System at Adaptive Clip
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1505 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1505 means on specific makes
Ford / Lincoln CAUTION
The PCM has run the idle-air-control adaptation to its limit ('clip') trying to keep idle correct — it's out of adjustment range. Typically a dirty/sticking IAC valve or an unmetered air (vacuum) leak. Common on older Fords with a separate IAC.
- Dirty/sticking IAC valve ($30-120)
- Vacuum leak ($0-200)
- Dirty throttle body ($0-30 to clean)
- PCV system fault ($20-80)
Check first: Clean the IAC valve and throttle body, then smoke-test for vacuum leaks.
Source: TroubleCodes.net Ford list