Idle Air Control Overspeed Error
Findings, check these first
- Vacuum leak letting unmetered air past the throttle
- Carbon-fouled or sticking idle air control valve
- Throttle plate coked open or misadjusted stop screw
- Stuck-open EGR valve at idle
- Faulty IAC driver circuit holding the valve open
Standard procedure
- Smoke test the intake system for vacuum leaks first
- Remove and clean the IAC valve and throttle body
- Compare commanded versus actual idle RPM on a scan tool
- Check the EGR valve for sticking open at idle
- Replace the IAC valve if cleaning does not restore idle control
Code lookup
Type a code above, or start from a symptom or a common code.
Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.
Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1506 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1506: Idle Air Control Overspeed Error
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1506 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1506: Idle Air Control Overspeed Error
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-04.
Report a correction for P1506. Include your vehicle, the issue and a source if you have one.