P0533-A/C PRESSURE SENSOR CIRCUIT HIGH
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
Engine running and the A/C Clutch Relay energized.
- Set Condition:
The A/C pressure transducer signal at the PCM goes above 4.92 volts. One trip Fault. Three good trips to turn off the MIL.
| Possible Causes |
| (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE |
| (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN |
| (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (F891) 5-VOLT SUPPLY CIRCUIT |
| (C918) SENSOR RETURN CIRCUIT OPEN |
| A/C PRESSURE TRANSDUCER |
| FCM |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Diagnostic Test
1. A/C PRESSURE TRANSDUCER VOLTAGE ABOVE 4.9 VOLTSNOTE: Make sure the A/C refrigerant System is properly charged per Service Information.
Start the engine.
With a scan tool, read the A/C Pressure Sensor voltage.
Is the voltage above 4.9 volts?
Yes
- Go To 2
No
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2. A/C PRESSURE TRANSDUCER
Turn the ignition off.
Disconnect the A/C Pressure Transducer harness connector.
Connect a jumper wire between the (C18) A/C Pressure Signal circuit and the (C918) Sensor Return circuit in the Transducer harness connector.
Ignition on, engine not running.
With the scan tool, monitor the A/C Pressure Transducer voltage.
Is the voltage below 1.0 volt with the jumper wire installed?
Yes
- Replace the A/C Pressure Transducer.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 3
NOTE: Remove the jumper wire before continuing.
3. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the C1 FCM harness connector.
Ignition on, engine not running.
Measure the voltage on the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector.
Is the voltage above 0 volts?
Yes
- Repair the short to battery voltage in the (C18) A/C Pressure Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 4
4. (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (C18) A/C Pressure Signal circuit from the A/C Pressure Transducer harness connector to the C1 FCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the open in the (C18) A/C Pressure Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (F891) 5-VOLT SUPPLY CIRCUIT
Measure the resistance between the (C18) A/C Pressure Signal circuit and the (F891) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.
Is the resistance below 5.0 ohms?
Yes
- Repair the short between the (F891) 5-volt Supply circuit and the (C18) A/C Pressure Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Go To 6
6. (C918) SENSOR RETURN CIRCUIT OPEN
Disconnect the IPM FCM harness connector.
Measure the resistance of the (C918) Sensor Return circuit from the A/C Pressure Sensor harness connector to the IPM FCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair the open in the (C918) Sensor Return circuit
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
7. FRONT CONTROL MODULE
NOTE: Before continuing, check the FCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes
- Repair as necessary.
- Perform BODY VERIFICATION TEST. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Replace and program the Front Control Module per Service Information.
- Perform BODY VERIFICATION TEST. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)