A/C Request Signal

This signal is transmitted two different ways depending on the content option, the first is communicated Class II from the HVAC Controller to the PCM that an A/C mode is selected (CJ2). The second is a 12 volt signal from the HVAC Controller to the PCM, the 12 volt signal indicates that an A/C mode is selected (CJ3, C60). The PCM uses this information to adjust the idle speed before turning on the A/C clutch. If this signal is not available to the PCM, the A/C compressor will be inoperative.

Refer to A/C Compressor Control Circuit Diagnosis for A/C clutch wiring diagrams and diagnosis of A/C clutch electrical system.