Idle Air Control Overspeed Error
2002-2005 Ford Explorer 4.6L V8
Description
The engine idle speed is too high. The PCM has detected that idle RPM exceeds the target idle speed and the IAC system cannot bring it down. The engine may be idling at 2000+ RPM.
Symptoms
- Check Engine Light
- Idle speed too high
- Engine races at idle
- Vehicle creeps forward in gear
Common Causes
- Vacuum leak (most common)
- IAC valve stuck open
- Throttle plate not closing fully
- Throttle body carbon buildup preventing closure
- Faulty IAC valve
- Intake manifold gasket leak
Diagnostic Steps
- Check for vacuum leaks with engine running — spray carb cleaner around intake
- Inspect throttle body for carbon preventing plate closure
- Test IAC valve — disconnect and check if idle drops
- Clean throttle body and IAC passages
- Inspect intake manifold gaskets
Repair Notes
Find and repair vacuum leak. Clean throttle body. Replace IAC valve if stuck open.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0001Fuel Volume Regulator Control Circuit/Open
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0003Fuel Volume Regulator Control Circuit Low
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
P1506 on Other Vehicles
Common Questions
What does code P1506 mean on a 2002-2005 Ford Explorer?
P1506 stands for "Idle Air Control Overspeed Error". The engine idle speed is too high. The PCM has detected that idle RPM exceeds the target idle speed and the IAC system cannot bring it down. The engine may be idling at 2000+ RPM.
What are the symptoms of P1506 on a Ford Explorer?
Common symptoms of P1506 include: Check Engine Light, Idle speed too high, Engine races at idle, Vehicle creeps forward in gear.
What causes P1506 on a 2002-2005 Ford Explorer?
Common causes of P1506 include: Vacuum leak (most common), IAC valve stuck open, Throttle plate not closing fully, Throttle body carbon buildup preventing closure, Faulty IAC valve, Intake manifold gasket leak.