P0532

P0532-A/C PRESSURE SENSOR CIRCUIT LOW






For a complete wiring diagram refer to: Electrical Diagrams

When Monitored
Engine running, A/C is learned, and AC Clutch Relay energized.

Set Condition
The A/C pressure sensor signal voltage at the PCM goes below 0.58 of a volt for 2.6 seconds. One Trip Fault. Three good trips to turn off the MIL.

Possible Causes
- (F891) 5-VOLT SUPPLY CIRCUIT OPEN
- (F891) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND A/C PRESSURE TRANSDUCER
- (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND
- (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO (C918) SENSOR GROUND CIRCUIT
- FRONT CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test
1. A/C PRESSURE TRANSDUCER VOLTAGE BELOW 0.6 OF A VOLT





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 below 0.6 of a volt?
Yes >> Go To 2
No >> Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. (F891) 5-VOLT SUPPLY CIRCUIT





Turn the ignition off.
Disconnect the A/C Pressure Transducer harness connector.
Ignition on, engine not running.
Measure the voltage on the (F891) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.

Is the voltage between 4.5 to 5.2 volts?
Yes >> Go To 3
No >> Go To 6
3. A/C PRESSURE TRANSDUCER





With the scan tool, monitor the A/C Pressure Transducer voltage.

Is the voltage above 0.6 of a volt?
Yes >> Replace the A/C Pressure Transducer.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 4
4. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND





Turn the ignition off.
Disconnect the C1 FCM harness connector.
Measure the resistance between the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector and ground.

Is the resistance below 100 ohms?
Yes >> Repair the short to ground in the (C18) A/C Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 5
5. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (C918) SENSOR GROUND CIRCUIT





Disconnect the C3 FCM harness connector.
Measure the resistance between the (C18) A/C Pressure Signal circuit and the (C918) Sensor Ground circuit in the A/C Pressure Transducer harness connector.

Is the resistance below 100 ohms?
Yes >> Repair the short between the (C918) Sensor Ground circuit and the (C18) A/C Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 8
6. (F891) 5-VOLT SUPPLY CIRCUIT OPEN





Turn the ignition off.
Disconnect the C1 FCM harness connector.
Measure the resistance of the (F891) 5-volt Supply 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 7
No >> Repair the open in the (F891) 5-volt Supply circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. (F891) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





Measure the resistance between the (F891) 5-volt Supply circuit in the A/C Pressure Transducer harness connector and ground.

Is the resistance below 100 ohms?
Yes >> Repair the short to ground in the (F891) 5-volt Supply circuit.
Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No >> Go To 8
8. 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-VER 1.
No >> Replace and program the Front Control Module per Service Information.
Perform BODY VERIFICATION TEST-VER 1.