How do I replace the IAC on My '00 Mazda MPV?

The Idle Air Control (IAC) valve controls the engine idle speed and dashpot functions.The valve is located on the side of the throttle body. This valve allows air, determined by the Powertrain Control Module (PCM) and controlled by a duty cycle signal, to bypass the throttle plate in order to maintain the proper idle speed.

The Idle Air Control (IAC) valve is an integral component of the Bypass Air Control (BAC) valve.

  • Disconnect the negative battery cable.
  • Disconnect the water hoses (if equipped) and air hose from the BAC/IAC valve.


  • Disengage the wiring harness connector from the BAC/IAC valve.
  • Remove the mounting fasteners from the valve assembly.
  • Remove the BAC/IAC valve assembly, along with the mounting gasket and O-ring from the vehicle.

    To install:

  • Remove any foreign material from the contact surface.
  • Install the BAC/IAC valve assembly, with a new mounting gasket and O-ring, onto the engine in correct position.
  • Install and tighten the mounting fasteners to 14–18 ft. lbs. (19–25 Nm) on 3.0L engines, and 22–30 inch lbs. (2.5–3.4 Nm) on 2.6L engines.
  • Plug in the valve wiring harness connector.
  • Connect the air hose and water hoses (if equipped) to the valve assembly.
  • Connect the negative battery cable.
  • If equipped with water hoses, verify that the valve assembly does not leak