On a Jeep Cherokee the IAC, or Idle Air Control Valve, controls the idle speed of the engine. The IAC receives an input signal from the vehicle's computer and contains a small electric motor that moves a plunger in and out of the air control passage. This ability to restrict air flowing through the air control passage sets the speed at which the engine idles.
Disconnect the ground cable from the negative battery terminal by loosening the clamp and lifting it off the negative battery terminal.
Separate the air intake duct from the throttle body by loosening the retaining clamp and carefully pulling the duct away from the throttle body.
Locate the Idle Air Control Valve (IAC). It will be located on the back of the throttle body.
Remove the electrical connector from the IAC.
Remove the two screws that secure the IAC to the throttle body.
Carefully pull the IAC from the throttle body.
Carefully slide the IAC into position in the throttle body.
Reinstall the two screws that secure it in place.
Reconnect the electrical connector to the IAC.
Slide the air intake duct onto the throttle body, and reinstall the retaining clamp.
Reconnect the ground cable to the negative battery terminal.
