P0533

P0533-A/C PRESSURE SENSOR CIRCUIT HIGH






For a complete wiring diagram refer to: Electrical Diagrams

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 (F891) 5-VOLT SUPPLY CIRCUIT
- (C918) SENSOR GROUND CIRCUIT OPEN
- A/C PRESSURE TRANSDUCER
- FRONT CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test
1. A/C PRESSURE TRANSDUCER VOLTAGE ABOVE 4.9 VOLTS





NOTE: 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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
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 Ground 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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
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 there voltage present?
Yes >> Repair the short to battery voltage in the (C18) A/C Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
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 POWERTRAIN VERIFICATION TEST.
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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 6
6. (C918) SENSOR GROUND CIRCUIT OPEN





Disconnect the C3 FCM harness connector.
Measure the resistance of the (C918) Sensor Ground circuit from the A/C Pressure Sensor harness connector to the C3 FCM harness connector.

Is the resistance below 5.0 ohms?
Yes >> Go To 7
No >> Repair the open in the (C918) Sensor Ground circuit
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. FRONT CONTROL MODULE

NOTE: Before continuing, check the PCM 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-VER 1.
No >> Replace and program the Powertrain Control Module per Service Information.
Perform BODY VERIFICATION TEST VER - 1. Body Verification Test