Climate Control Switch Communication Line Circuit Troubleshooting (With Climate Control)

Climate Control Switch Communication Line Circuit Troubleshooting

1. Operate the climate control system with the passenger's climate control switch in all modes.

Does the climate control system operate?
YES - Intermittent failure. Check for loose wires or poor connections at the driver's and passenger's climate control switches, and at the climate control unit.

NO - Go to step 2.


2. Operate the climate control system with the driver's climate control switch in all modes.

Does the climate control system operate?
YES - Go to step 3.

NO - Go to step 11.


3. Turn the ignition switch to LOCK (0).

4. Disconnect the passenger's climate control switch 12P connector.

5. Turn the ignition switch to ON (II).

6. Measure the voltage between body ground and the passenger's climate control switch 12P connector No. 1 terminal.

Is there battery voltage?
YES - Go to step 7.

NO - Repair open in the LT GRN wire.






7. Turn the ignition switch to LOCK (0).

8. Disconnect the driver's climate control switch 16P connector.

9. Check for continuity between the following terminals of the passenger's climate control switch 12P connector and the driver's climate control switch 16P connector.





Is there continuity?
YES - Go to step 10.

NO - Repair open in the wires between the driver's climate control switch and the passenger's climate control switch.






10. Check for continuity between body ground and the passenger's climate control switch 12P connector terminals No. 7, No. 8, No. 9, No. 10, No. 11, and No. 12.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the driver's climate control switch and the passenger's climate control switch.

NO - Substitute a known-good passenger's climate control switch, and recheck. If the symptom goes away, replace the original passenger's climate control switch. Climate Control Unit Removal/Installation (Without Navigation)






11. Disconnect the driver's climate control switch 16P connector.

12. Turn the ignition switch to ON (II).

13. Measure the voltage between body ground and the driver's climate control switch 16P connector No. 11 terminal.

Is there battery voltage?
YES - Go to step 14.

NO - Repair open in the wire between the driver's climate control switch and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.






14. Turn the ignition switch to LOCK (0).

15. Check for continuity between body ground and the driver's climate control switch 16P connector No. 14 terminal.

Is there continuity?
YES - Go to step 16.

NO - Check for an open in the wire between the driver's climate control switch and body ground. If the wire is OK, check for poor ground at G401.






16. Disconnect climate control unit connector A (28P).

17. Check for continuity between the driver's climate control switch 16P connector No. 13 terminal and climate control unit connector A (28P) No. 28 terminal.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wire(s) between the driver's climate control switch and the climate control unit.






18. Check for continuity between driver's climate control switch 16P connector No. 13 and No. 14 terminals.

Is there continuity?
YES - Repair short to another wire.

NO - Go to step 19.






19. Reconnect the driver's climate control switch 16P connector.

20. Reconnect climate control unit connector A (28P).

21. Press and hold the FAN UP switch, then press the OFF switch.

Is the REC button LED blinking?
YES - Go to step 22.

NO - Substitute a known-good driver's climate control switch, and recheck the function. If the symptom is still present, replace the climate control unit. Service and Repair

22. Check the driver's climate control switch LEDs.

Are the REC button and AUTO button LEDs blinking?
YES - Driver's climate control switch is faulty, replace the driver's climate control switch. Climate Control Unit Removal/Installation (Without Navigation)

NO - Go to step 23.


23. Check the driver's climate control switch LEDs.

Are the REC button and DUAL button LEDs blinking?
YES - Substitute a known-good driver's climate control switch, and recheck the function. If the symptom is still present, replace the climate control unit. Service and Repair

NO - Check for loose wires or poor connections at climate control unit connector A (28P) and driver's climate control switch 16P connector. If the connections are good, replace the climate control unit. Service and Repair