Manual HVAC
A/C Pressure Switch Circuit TroubleshootingNOTE:
- Do not use this troubleshooting procedure if any of the following items are operative: condenser fan, radiator fan, A/C compressor, or if the heater is inoperative. Refer to the symptom troubleshooting index. Symptom Related Diagnostic Procedures
- Before performing symptom troubleshooting, check for powertrain DTCs.
1. Check for body DTCs in test mode A of the MICS.
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 4P connector.
3. Turn the ignition switch ON (II).
4. Measure the voltage between the No.1 terminal of the A/C pressure switch 4P connector and body ground.
Is there 5V or more?
YES - Go to step 5.
NO - Repair open in the wire between the relay module and the A/C pressure switch. If the wire is OK, replace the relay module.
5. Turn the ignition switch OFF.
6. Check for continuity between the No.1 and No.4 terminals of the A/C pressure switch.
Is there continuity?
YES - Go to step 7.
NO - Go to step 16.
7. Reconnect the A/C pressure switch 4P connector.
8. Disconnect audio-HVAC display panel 22P connector.
9. Turn the ignition switch ON (II).
10. Measure the voltage between the No.1 terminal of audio-HVAC display panel 22P connector and body ground.
Is there 5V or more?
YES - Go to step 11.
NO - Repair the open in the wire between the audio-HVAC display panel and the A/C pressure switch.
11. Turn the ignition switch off.
12. Measure the resistance between the No.9 and No.10 terminals of the audio-HVAC display panel 22P connector.
Is the resistance less than 24 kOhms?
YES - Go to step 13.
NO - Repair cause of high resistance in the evaporator temperature circuit.
13. Reconnect the audio-HVAC display panel 22P connector.
14. Turn the ignition switch ON (II).
15. Check the blower motor operation at several speeds.
Does the blower motor operate at all speeds?
YES - Check for loose wires or poor connections at the audio-HVAC display panel 22P connector 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 front panel assembly.
NO - Repair the problem in the blower motor circuit.
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.