P1507 FORD, JAGUAR, LINCOLN, MAZDA, MERCURY: IDLE AIR CONTROL UNDER SPEED ERROR
POST UPDATED IN January, 2023
P1507 Code failures by brands
Description of DTC code P1507
The Idle Air Control (IAC) Valve assembly adjusts the engine idle speed, and also provides a dash function. This valve assembly measures the amount of intake air around the throttle plate, via a control bypass located on the inside of the IAC assembly and throttle body.
The Powertrain Control Module (PCM) controls the necessary idle speed. It indicates this factor to the IAC assembly using a detailed duty cycle. In response to that action, the valve is positioned to control the amount of bypass air. The PCM also constantly monitors engine RPM and increases or decreases the IAC duty cycle as required to achieve the desired RPM.
The P1507 OBDII diagnostic code is set by the PCM when an engine idle airspeed is detected, which is below the desired engine speed.
Symptoms of fault code P1507
- Check Engine light ON.
- Irregular operation during idling.
Causes of OBD2 P1507
Reasons for storing the P1507 OBD2 fault code:
- The Idle Air Control Valve circuit may be open because of damage to its wiring or connectors.
- The IAC valve may be stuck.
- The idle Air Control Valve may be faulty.
Possible solutions of the DTC code P1507
The steps to solve the P1507 OBDII DTC:
- Consult the TSBs.
- Check all the electrical components that belong to the Idle Air Control Valve circuit, and check that all of them meet the requirements for the right operation. In case of finding common damages, make the respective corrections.
- Measure the IAC Valve circuit voltages, and verify that they match the manufacturer's specifications. If you find some differences that indicate a short or open circuit, repair if necessary.
- Check the IAC Valve for blockages that prevent proper operation. If you discover such conditions, make the appropriate adjustments.
- If even after performing the above checks you still get the code P1507, there may be a faulty IAC valve.
