DTC Troubleshooting

Control System DTCs

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 How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-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- The failure is duplicated. Go to step 2.
-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.

2. Determine possible failure area (A/C pressure sensor, others):

Determine possible failure area (A/C pressure sensor, others)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Connect terminals A and B with a jumper wire.









-4. Turn the ignition switch to ON (II).

-5. 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 3.
-NO- Replace the A/C pressure sensor Service and Repair, then do the repair verification.

3. Determine possible failure area (PD_SENSOR line, SG6 line):

Determine possible failure area (PD_SENSOR line, SG6 line)
-1. Turn the ignition switch to LOCK (0).

-2. Remove the jumper wire.

-3. Turn the ignition switch to ON (II).

-4. Measure the voltage between test points 1 and 2.









Is there about 5.0 V?
-YES- Go to step 4.
-NO- Go to step 5.

4. Open wire check (PD_SENSOR line):

Open wire check (PD_SENSOR line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The PD_SENSOR wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.
-NO- Repair an open in the PD_SENSOR wire between the ECM (A27) and the A/C pressure sensor, then do the repair verification.

5. Open wire check (SG6 line):

Open wire check (SG6 line)
-1. Turn the ignition switch to LOCK (0).

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- The SG6 wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.
-NO- Repair an open in the SG6 wire between the ECM (A10) and the A/C pressure sensor, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM idle learn procedure ECM/PCM Idle Learn Procedure.

-6. Start the engine, and let it idle.

-7. Turn the blower switch on.

-8. Turn the A/C switch on.

-9. Check for Pending or Confirmed 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 Service and Repair, then recheck. If the ECM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the ECM was substituted, replace the original ECM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.