Diagnostic Procedures
- Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
- Install A/C manifold gauge set. If low side refrigerant pressure is greater than 45 psi (3.2 kg/cm2 ), go to next step. If the refrigerant pressure is not as specified, diagnose A/C system.
- Turn ignition on, with engine off. Using scan tool, monitor A/C high side refrigerant pressure. Compare pressure reading on scan tool to reading on manifold gauge set. If both pressure readings are within 10 psi (.71 kg/cm2 ) of each other, go to next step. If pressure reading is not as specified, go to step 6).
- Start engine. Turn A/C off for 10 seconds, then turn A/C on and wait for about 10 seconds. If DTC P0531 is set, diagnose DTC. If DTC P0531 is not set, diagnose A/C system.
- If A/C compressor clutch engages, diagnose A/C system. If A/C compressor clutch does not engage, diagnosis.
- Turn ignition off. Disconnect A/C refrigerant pressure sensor. Using a test light connected to battery voltage, probe sensor harness connector terminal "A" (Gray wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 10).
- Check connection at A/C refrigerant pressure sensor. Repair as necessary. After repairs, go to step 9). If connection is okay, go to next step.
- Replace A/C refrigerant pressure sensor.
- Repair connector.
- Repair open in A/C refrigerant pressure sensor ground circuit.