XB55 - Check ACP Circuit For Short to Ground

- Key "OFF".

- A/C Pressure (ACP) sensor disconnected.

- Disconnect Variable Control Relay Module (VCRM).

- Measure resistance between the ACP circuit at the ACP sensor vehicle harness connector and the battery negative post.

- Measure resistance between the ACP circuit and the ACP SIG RTN circuit at the ACP sensor vehicle harness connector.

- Are both resistances greater than 10,000 ohms?

Yes -- Replace VCRM. Remove A/C system Manifold Gauge set. Reconnect all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Attempt to reset Diagnostic Trouble Code (DTC) 579 (refer to XB52 for procedure only). XB52 - Clear and Attempt to Regenerate DTC

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Service ACP circuit short to ground or SIG RTN. Remove A/C system Manifold Gauge Set. Reconnect all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Attempt to reset DTC 579 (refer to XB52 for procedure only). XB52 - Clear and Attempt to Regenerate DTC

Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)