X27 - Check ACPSW Medium Pressure Contact Circuit: Short to GND

- Key "OFF".

- AC Pressure Switch (ACPSW) disconnected.

- Disconnect Constant Control Relay Module (CCRM).

- Measure resistance between Pin 17 at the CCRM vehicle harness connector and the battery negative post.

- Is resistance greater than 10,000 ohms?

Yes -- Replace CCRM. Reconnect all components. Re-evaluate symptom.

No -- Service short to ground. Reconnect all components. Re-evaluate symptom.