DTC Troubleshooting

DTC Troubleshooting: P0533

DTC P0533: A/C Pressure Sensor Circuit High Voltage

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

1. Start the engine, and let it idle.

2. Turn the blower switch on.

3. Turn the A/C switch on.

4. Check the A/C PRESSURE SENSOR in the DATA LIST with the HDS.

Is there about 4.75 V or more?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/C pressure sensor and the ECM.


5. Turn the ignition switch to LOCK (0).

6. Disconnect the A/C pressure sensor 3P connector.

7. Connect A/C pressure sensor 3P connector terminals No. 2 and No. 3 with a jumper wire.

8. Turn the ignition switch to ON (II).

9. Check the A/C PRESSURE SENSOR in the DATA LIST with the HDS.

Is there about 4.75 V or more?
YES - Go to step 10.

NO - Go to step 22.






10. Turn the ignition switch to LOCK (0).

11. Remove the jumper wire from the A/C pressure sensor 3P connector.

12. Turn the ignition switch to ON (II).

13. Measure the voltage between A/C pressure sensor 3P connector terminals No. 1 and No. 3.

Is there about 5 V?
YES - Go to step 14.

NO - Go to step 18.






14. Turn the ignition switch to LOCK (0).

15. Jump the SCS line with the HDS.

16. Disconnect ECM connector A (44P).

17. Check for continuity between A/C pressure sensor 3P connector terminal No. 2 and ECM connector terminal A16.

Is there continuity?
YES - Go to step 32.

NO - Repair open in the wire between the ECM (A16) and the A/C pressure sensor, then go to step 24.






18. Turn the ignition switch to LOCK (0).

19. Jump the SCS line with the HDS.

20. Disconnect ECM connector A (44P).

21. Check for continuity between A/C pressure sensor 3P connector terminal No. 3 and ECM connector terminal A9.

Is there continuity?
YES - Go to step 32.

NO - Repair open in the wire between the ECM (A9) and the A/C pressure sensor, then go to step 24.






22. Turn the ignition switch to LOCK (0).

23. Replace the A/C pressure sensor. Service and Repair

24. Reconnect all connectors.

25. Turn the ignition switch to ON (II).

26. Reset the ECM with the HDS.

27. Do the ECM idle learn procedure. ECM Idle Learn Procedure

28. Start the engine, and let it idle.

29. Turn the blower switch on.

30. Turn the A/C switch on.

31. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0533 indicated?
YES - Check for poor connections or loose terminals at the A/C pressure sensor and the ECM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


32. Reconnect all connectors.

33. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview

34. Start the engine, and let it idle.

35. Turn the blower switch on.

36. Turn the A/C switch on.

37. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0533 indicated?
YES - Check for poor connections or loose terminals at the A/C pressure sensor and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 34. If the ECM was substituted, go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.