NGC

P0532-A/C PRESSURE SENSOR CIRCUIT LOW





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:
The PCM detects that the A/C Pressure Transducer input voltage is below the minimum acceptable value.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. ACTIVE DTC
NOTE: Diagnose any CAN - C Communication DTCs before continuing.

NOTE: Make sure the A/C refrigerant System is properly charged.

Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.

With the scan tool, select View DTCs.
Is the DTC Active at this time?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking For An Intermittent DTC

2. (C818) 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 (C818) 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 7

3. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND




Turn the ignition off.
Disconnect the C1 TIPM 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 the PCM Verification Test. Powertrain Verification Test

No

- Go to 4

4. (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (C918) SENSOR GROUND CIRCUIT




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 the PCM Verification Test. Powertrain Verification Test

No

- Go to 5

5. (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN




Measure the resistance of the (C18) A/C Pressure Signal circuit from the A/C Pressure Transducer harness connector to C1 TIPM harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

- Repair the excessive resistance in the (C18) A/C Pressure Signal circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

6. A/C PRESSURE TRANSDUCER
Connect the C1 TIPM harness connector.
Turn the ignition on.
With the scan tool, monitor the A/C Pressure Transducer voltage.

NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes

- Verify that there is good pin to terminal contact in the A/C Pressure Transducer and the Powertrain Control Module connectors. If OK, replace the A/C Pressure Transducer.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 9

7. (C818) 5-VOLT SUPPLY CIRCUIT OPEN




Turn the ignition off.
Disconnect the C1 TIPM harness connector.
Measure the resistance of the (C818) 5-volt Supply circuit from the A/C Pressure Transducer harness connector to the C1 TIPM harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 8

No

- Repair the open in the (C818) 5-volt Supply circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

8. (C818) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND




Measure the resistance between ground and the (C818) 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 (C818) 5-volt Supply circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 9

9. TOTALLY INTEGRATED POWER MODULE
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the related A/C Pressure Transducer and the Totally Integrated Power Module (TIPM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the A/C Pressure Transducer and the Totally Integrated Power Module connectors.
Search for any Technical Service Bulletins that may apply.
Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test