DTC P0532: A/C Pressure Sensor Low: Testing
- Start the engine. With the DRBIII®, read the A/C Pressure Sensor voltage. Is the voltage below 0.6 volt? If yes, go to next step. If no, go to step 10.
- Turn the ignition off. Disconnect the A/C Pressure Sensor harness connector. A/C pressure sensor has a Gray connector and is located on A/C discharge refrigerant line, near compressor. Turn ignition on, engine not running. Measure the voltage of the 5-Volt Supply circuit in the A/C Pressure Sensor harness connector. Is the voltage between 4.5 and 5.2 volts? If yes, go to next step. If no, go to step 7.
- With the DRBIII®, monitor the A/C Pressure Sensor voltage. Is the voltage above 0.6 volt? If yes, replace the A/C Pressure Sensor. If no, go to next step.
- Turn the ignition off. Disconnect the PCM harness connectors. Measure the resistance between ground and the A/C Pressure Sensor Signal circuit in the A/C Pressure Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the short to ground in the A/C Pressure Sensor Signal circuit. If no, go to next step.
- Measure the resistance between the A/C Pressure Sensor Signal circuit and the Sensor Ground circuit in the A/C Pressure Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the A/C Pressure Sensor Signal circuit for a short to the Sensor Ground circuit. If no, go to next step.
- There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
- Turn the ignition off. Ensure A/C Pressure Sensor is disconnected. Disconnect the PCM harness connectors. Measure the resistance between ground and the 5-Volt Supply circuit in the A/C Pressure Sensor harness connector. Is the resistance below 100 ohms? If yes, repair the short to ground in the 5-Volt Supply circuit. If no, go to next step.
- Measure the resistance of the 5-Volt Supply circuit from the A/C Pressure Sensor harness connector to the appropriate terminal at Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the 5-Volt Supply circuit.
- There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
- The conditions that set the DTC are not present at this time. The following may help in identifying the intermittent condition. With the engine running at normal operating temperature, monitor the DRBIII® parameters related to the DTC while wiggling the wiring harness. Look for parameter values to change and/or a DTC to set. Review the DRBIII® Freeze Frame information. If possible, try to duplicate the conditions under which the DTC was set. Refer to any Technical Service Bulletins (TSB) that may apply. Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Were any of the above conditions present? If yes, repair as necessary. If no, test is complete.
NOTE:
Ensure the A/C system is properly charged with refrigerant.
NOTE:
Before continuing, check the PCM harness connectors for corrosion, damage or terminal push out. Repair as necessary.
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
NOTE:
Before continuing, check the PCM harness connectors for corrosion, damage or terminal push out. Repair as necessary.
NOTE:
Ensure the A/C refrigerant System is properly charged
WARNING:
When the engine is operating, do not stand in a direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing.