Technician A says the IAC counts should change when the A/C compressor is turned on and off. Technician B says if the scan tester indicates zero IAC counts, there may be an open circuit between the PCM and the IAC motor. Who is correct?

Question

Quizplus · Accepted Answer

Technician A is correct because the Idle Air Control (IAC) valve adjusts the engine's idle speed, and turning the A/C compressor on increases the engine's load, requiring an adjustment in idle speed. Technician B is correct because if the scan tool shows zero IAC counts, it could indicate a lack of communication between the Powertrain Control Module (PCM) and the IAC motor, possibly due to an open circuit.

Technician a Says the IAC Counts Should Change When the A/C