P0532

SYMPTOM
P0532-A/C PRESSURE SENSOR CIRCUIT LOW

WHEN MONITORED
Engine running,AC 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
- (T103) 5-VOLT SUPPLY CIRCUIT OPEN
- (T103) 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 (G180) SENSOR RETURN CIRCUIT
- FRONT CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Scan Tool Testing and Procedures

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>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-2. Powertrain Verification Test - Ver 2

2. (T103) 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 (T103) 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 (NGC) POWERTRAIN VERIFICATION TEST VER-2.
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 ground and the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (C18) A/C Pressure Signal circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-2.
No>> Go To 5

5. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (G180) SENSOR RETURN CIRCUIT





Disconnect the C3 FCM harness connector. Measure the resistance between the (C18) A/C Pressure Signal circuit and the (G180) Sensor Return circuit in the A/C Pressure Transducer harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short between the (G180) Sensor Return circuit and the (C18) A/C Pressure Signal circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-2.
No>> Go To 8

6. (T103) 5-VOLT SUPPLY CIRCUIT OPEN





Turn the ignition off.
Disconnect the C1 FCM harness connector.
Measure the resistance of the (T103) 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 (T103) 5-volt Supply circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-2.

7. (T103) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (T103) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (T103) 5-volt Supply circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-2.
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.