P0508 - IDLE AIR CONTROL CIRCUIT LOW

DTC P0508 OBDII is stored next to the Check Engine light when the PCM (Powertrain Control Module) finds inconsistencies in the engine idle RPM.

It should be noted that when the PCM observes excessively slow engine operation, it attempts to correct the RPM, if unable to make those adjustments it sets this code.

No one likes to have a vehicle that is not running properly. And the P0508 code is a great indication that the vehicle is not running well at all. This could mean that the engine will stall at low speeds and when not pressing the accelerator, such as waiting for a brake light or even going into a turn. This can cause serious problems and it’s really dangerous to drive a car with such a fault. It is important to be aware of this code as soon as possible to ensure proper vehicle performance. Those who do not take care of this and other codes may find that their vehicle develops other problems as well.

• MIL (Malfunctioning Engine) light on.
• The engine may stall at low speeds.
• When not pressing the accelerator the engine may stall.
• Unusual noises in the throttle body area.
• Other codes related to IAC.

P0508 OBD2 fault code is stored due to the following:

• The IAC Valve (Idle Valve) is possibly faulty.
• The engine vacuum may be leaking.
• The wires or respective connectors related to the IAC Valve could be short-circuited.
• The throttle body or IAC Valve may have excessive carbon buildup.
• PCM programming error or defective PCM.

When troubleshooting the faults caused by the P0508 OBDII diagnostic code you should do the following:

• Consult the corresponding TSB (Technical Service Bulletins) for your vehicle.
• Examine the IAC cable system. Repair any damage you find and, if necessary, replace the defective component.
• Check the throttle body, if it has carbon residue, clean it.
• Replace the IAC Valve.