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A/C Pressure Switch Circuit Troubleshooting

A/C Pressure Switch Circuit Troubleshooting

NOTE:
- Do not use this troubleshooting procedure if the following items are operative; condenser fan, A/C compressor, or if the heater is inoperative. Refer to the symptom troubleshooting index. Climate Control
- Before performing symptom troubleshooting, check for powertrain DTCs.

1. Check for body DTCs in test mode A of the multiplex integrated control system.

Are there any DTCs indicated?

YES - Do the appropriate troubleshooting for the DTC indicated.

NO - Go to step 2.

2. Disconnect the A/C pressure switch 2P connector.
3. Turn the ignition switch ON (II).




4. Measure the voltage between the No. 1 terminal of the A/C pressure switch 2P connector and body ground.

Is there 5 V or more?

YES - Go to step 5.

NO - Go to step 13.

5. Turn the ignition switch OFF.




6. Check for continuity between the No. 1 and No. 2 terminals of the A/C pressure switch.

Is there continuity?

YES - Go to step 7.

NO - Go to step 14.

7. Reconnect the A/C pressure switch 2P connector.
8. Disconnect audio-HVAC display panel connector A (22P)
9. Turn the ignition switch ON (II).




10. Measure the voltage between the No. 5 terminal of the audio-HVAC display panel connector A (22P) and body ground.

Is there 5 V or more?

YES - Go to step 11.

NO - Repair open in the wire between the climate control unit and the A/C pressure switch.

11. Turn the ignition switch OFF.




12. Measure the resistance between the No. 14 and No. 15 terminals of the audio-HVAC display panel connector A (22P).

Is the resistance less than 24 kohms?

YES - Check for loose wires or poor connections at audio-HVAC display panel connector A (22P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known-good audio-HVAC display panel, and recheck. If the symptom/indication goes away, replace the original audio-HVAC display panel.

NO - Repair cause of high resistance in the evaporator temperature circuit.




13. Measure the voltage between the No. 2 terminal of under-hood fuse/relay box connector H (14P) and body ground with the under-hood fuse/relay box connectors connected.

Is there 5 V or more?

YES - Repair open in the wire between the under-hood fuse/relay box and the A/C pressure switch.

NO - Check for loose or poor connections at the No. 2 terminal of the under-hood fuse/relay box. If the Connections are OK, replace the under-hood fuse/relay box.

14. 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 switch.