XB91 - Check If PCM Is Receiving and Recognizing ACCS Input

- Key "OFF".

- Remove test lamp.

- Reconnect A/C clutch.

- A/C "ON".

- Perform Key On Engine Off Self-Test. Quick Test Appendix (Detailed Testing Instructions)

- Is Key On Engine Off Diagnostic Trouble Code (DTC) 539 present?

Yes -- The Powertrain Control Module (PCM) is receiving and recognizing the AC Clutch Supply (ACCS) input. Go to XB92 (to verify the Variable Control Relay Module (VCRM) is receiving the A/C demand voltage). XB92 - Check A/C Demand Switch Voltage at VCRM

No -- The PCM is not receiving or recognizing the ACCS input. Go to XB96. XB96 - Check For A/C Demand Voltage at A/C Pressure Switch