Idle Air Control Valve Sense Circuit High
Table of contents
P0509 JEEP Possible Causes
- Faulty Idle Air Control (IAC) motor
- Idle Air Control (IAC) motor harness is open or shorted
- Idle Air Control (IAC) motor circuit poor electrical connection
How do I fix code P0509 JEEP?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the P0509 JEEP code
The cost of diagnosing the P0509 JEEP code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The PCM senses a short to ground or battery voltage on any of the control circuits for 2.75 seconds while the IAC motor is active.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine hard to start
- Rough or erratic idle speed
P0509 JEEP Description
The Engine Control Module (ECM) controls the engine idle speed to a specified level through the fine adjustment of the air, which is let into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is varied to allow for optimum control of the engine idling speed. The ECM calculates the actual engine speed from signals of crankshaft position sensor (POS) and camshaft position sensor.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily. The optimum value stored in the ECM is determined by taking into consideration various engine conditions, such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan operation, etc.)