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A/C Pressure Switch Circuit Troubleshooting

A/C Pressure Switch Circuit Troubleshooting

NOTE:
- Do not use this troubleshooting procedure if any of the following items are operative; A/C condenser fan, radiator fan, A/C compressor. Refer to the symptom troubleshooting index. Heating/Air Conditioning
- Before performing symptom troubleshooting, check for powertrain DTCs.

1. Check for body DTCs using B-CAN system diagnosis test mode A troubleshooting.

Are there any DTCs indicated?

YES - Do the appropriate troubleshooting for the DTC indicated.

NO - Go to step 2.

2. Check that the front blower motor operates at all speeds.

Does the front blower motor operate at all speeds?

YES - Go to step 3.

NO - Repair the problem in the front blower motor circuit.

3. Disconnect the A/C pressure switch 4P connector.
4. Turn the ignition switch to ON (II).
5. Measure the voltage between the No. 1 terminal of the A/C pressure switch 4P connector and body ground.






Is there 5 V or more?

YES - Go to step 6.

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

6. Turn the ignition switch to LOCK (0).
7. Check for continuity between the No. 1 and No. 4 terminals of the A/C pressure switch.






Is there continuity?

YES - Go to step 8.

NO - Go to step 16.

8. Reconnect the A/C pressure switch 4P connector.
9. Disconnect A/C control panel connector A (22P).
10. Turn the ignition switch to ON (II).
11. Measure the voltage between the No. 4 terminal of A/C control panel connector A (22P) and body ground.






Is there 5 V or more?

YES - Go to step 12.

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

12. Turn the ignition switch to LOCK (0).
13. Measure the evaporator temperature sensor resistance between the No. 3 and No. 14 terminals of A/C control panel connector A (22P).






Is the resistance less than 24 kohms?

YES - Go to step 14.

NO - Test the evaporator temperature sensor.

14. Reconnect A/C control panel connector A (22P).
15. Turn the ignition switch to ON (II).
16. 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.