P0505 - IDLE CONTROL SYSTEM MALFUNCTION

The Idle Air Control (IAC Valve) regulates the velocity of the vehicle when it is idling. The Minimum Valve (IAC) is controlled by the PCM (Power Train Control Module) and this allows around the accelerator plate only a low percentage of air. This portion of air is what inspects the idle speed.

The Idle Air Control Valve has an opener, which makes movements to open and close the air passage. The greater the amount of air that the minimum valve provides around the throttle plate, the more inactivity there is.

The IAC Valve is used by the Powertrain Control Module so that the idling speed is correct as requested by the vehicle. The voltages of the circuits of the Idle Air Control Valve are constantly monitored by the PCM and, in case a voltage is detected incorrectly in one of the circuits, the DTC code P0505 OBD2 is established.

• Check Engine light on the board.
• Unstable motor.
• If there are vacuum leaks, the engine works with those leaks.
• The engine may stop.

The reasons that can lead to the establishment of fault code P0505 are the following:

• The valve connector of the minimum valve may be defective.
• Voltage circuit or Idle Air Control valve ground can be shorted.
• The IAC Valve may be defective.

To solve the problems caused by the diagnostic code P0505 OBD II, you must do the following:

• Disconnect the Idle Air Control valve, and then start the engine. With your automotive scanner it takes the fault codes and although other codes may appear, if the code is not reset P0505 indicates an internal short in one of the circuits of the IAC Valve. Change it if necessary.
• In case the code comes back, having the IAC disconnected and the engine turned on, you should check the cable system that goes from the IAC to the PCM. Make sure there are no broken, worn or rubbing cables with any other component. Repair or change as necessary.