A/C Pressure Switch Circuit Troubleshooting (With Climate Control)
A/C Pressure Switch Circuit Troubleshooting
NOTE:
- Do not use this troubleshooting procedure if any of the following items are operative when the climate control system is turned on: The A/C condenser fan, the radiator fan, or the A/C compressor. Refer to the symptom troubleshooting index .
- Before doing any symptom troubleshooting, check for powertrain DTCs Initial Inspection and Diagnostic Overview.
- If the blower motor does not run at all speeds, the A/C compressor will be inoperative. Before performing any other troubleshooting, repair the cause of the inoperative blower motor.
1. Check for body DTCs using B-CAN system diagnosis test mode A troubleshooting Troubleshooting - B-CAN System Diagnosis Test Mode A.
Are there any DTCs indicated?
YES -
Do the appropriate troubleshooting for the DTC indicated.�
NO -
Go to step 3.
2. Refer to the PGM-FI ECU Data List.
Is the A/C switch off?
YES -
Go to step 3.
NO -
Refer to the symptom troubleshooting index.�
3. Disconnect the A/C pressure switch 4P connector.
4. Turn the ignition switch to ON (II).
5. Measure the voltage between A/C pressure switch 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 6.
NO -
Go to step 20.
6. Connect the A/C pressure switch 4P connector terminal No. 4 to body ground with a jumper wire.
7. Start the engine.
Does the compressor and fans come on?
YES -
Go to step 8.
NO -
Check for loose wires or poor connections at under-hood fuse/relay box connector H (18P). If the connections are good, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
8. Turn the ignition switch to LOCK (0), then disconnect the jumper wire.
9. Check for continuity between A/C pressure switch terminals No. 1 and No. 4.
Is there continuity?
YES -
Go to step 10.
NO -
Go to step 19.
10. Reconnect the A/C pressure switch 4P connector.
11. Disconnect the climate control unit 30P connector.
12. Turn the ignition switch to ON (II).
13. Measure the voltage between climate control unit 30P connector terminal No. 29 and body ground.
Is there battery voltage?
YES -
Go to step 14.
NO -
Repair an open in the wire between the climate control unit and the A/C pressure switch.�
14. Turn the ignition switch to LOCK (0).
15. Measure the evaporator temperature sensor resistance between climate control unit 30P connector terminals No. 7 and No. 22.
Is the resistance less than 24 kOhms?
YES -
Go to step 16.
NO -
Test the evaporator temperature sensor Evaporator Temperature Sensor Test.�
16. Reconnect the climate control unit 30P connector.
17. Turn the ignition switch to ON (II).
18. Check that blower motor operates at all speeds.
Does the blower motor operate at all speeds?
YES -
Check for loose wires or poor connections at the climate control unit 30P connector and the A/C pressure switch 4P 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 Climate Control Unit Removal/Installation.�
NO -
Repair the problem in the blower motor circuit.�
19. Check for proper A/C system pressure.
Is the pressure within specifications?
YES -
Replace the A/C pressure switch.�
NO -
Troubleshoot the A/C pressure problem A/C System Test.�
20. Disconnect under-hood relay box connector H (18P).
21. Check for continuity between A/C pressure switch 4P connector terminal No. 4 and under-hood relay box connector H (18P) terminal No. 3.
Is there continuity?
YES -
Check for loose wires or poor connections at under-hood fuse/relay box connector H (18P) and A/C pressure switch 4P connector. If the connections are good, replace the under-hood fuse/relay box Under-Hood Fuse/Relay Box Removal and Installation.�
NO -
Repair an open in the wire between the relay control module and the A/C pressure switch.�