A/C System Troubleshooting
A/C System Troubleshooting1. Disconnect the A/C pressure switch 2P connector.
2. Turn the ignition switch ON (II).
3. Measure the voltage between the No.2 terminal of the A/C pressure switch 2P connector and body ground.
Is there approximately 5 V?
YES - Go to step 4.
NO - Go to step 10.
4. Turn the ignition switch OFF.
5. Check for continuity between the No.1 and No.2 terminals of the A/C pressure switch.
Is there continuity?
YES - Go to step 6.
NO - Go to step 11.
6. Reconnect the A/C pressure switch 2P connector.
7. Disconnect the climate control unit connector B (20P).
8. Turn the ignition switch ON (II).
9. Measure the voltage between the No.11 terminal of the climate control unit connector B (20P) and body ground.
Is there approximately 5 V?
YES - Check for loose wires or poor connections at the climate control unit connector B (20P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.
NO - Repair open in the wire between the climate control unit and the A/C pressure switch.
10. Using a Backprobe Set, measure the voltage between the No.27 terminal of the PCM connector A (32 P) and body ground with the PCM connectors connected.
IS there approximately 5 V?
YES - Repair open in the wire between the PCM and the A/C pressure switch.
NO - Check for loose wires or poor connections at the PCM connector A (32P). If the connections are good, substitute a known-good PCM, and recheck. If the symptom/indication goes away, replace the original PCM.
11. Check for proper A/C system pressure.
Is the pressure within specifications?
YES - Replace the A/C pressure switch.
NO - Repair the A/C pressure problem.