Idle Air Control System Circuit High
2011-2011 Mitsubishi Lancer 2.4L I4
The 2011 Mitsubishi Lancer is equipped with a 2.4L inline-4 engine. Below you'll find detailed p0509 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
High voltage in IAC circuit.
Symptoms
- High idle
- Racing idle
Common Causes
- Short to power
- Faulty IAC motor
- Open ground
Diagnostic Steps
- Test IAC voltage
- Check for shorts to power
Repair Notes
Replace IAC or repair wiring.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0509 on Other Vehicles
Mitsubishi 3000GT
1996-1996 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1997-1997 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1998-1998 3.0L V6 Twin Turbo
Mitsubishi 3000GT
1999-1999 3.0L V6 Twin Turbo
Mitsubishi Colt JP
2002-2002 1.3L I4 4A90
Mitsubishi Colt JP
2002-2002 1.5L I4 4A91
Mitsubishi Colt JP
2003-2003 1.3L I4 4A90
Mitsubishi Colt JP
2003-2003 1.5L I4 4A91
Common Questions
What does code P0509 mean on a 2011-2011 Mitsubishi Lancer?
P0509 stands for "Idle Air Control System Circuit High". High voltage in IAC circuit.
What are the symptoms of P0509 on a Mitsubishi Lancer?
Common symptoms of P0509 include: High idle, Racing idle.
What causes P0509 on a 2011-2011 Mitsubishi Lancer?
Common causes of P0509 include: Short to power, Faulty IAC motor, Open ground.
Last updated: March 2026