Climate Control Switch Communication Line Circuit Troubleshooting
Climate Control Switch Communication Line Circuit Troubleshooting
'08-10 models
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 passenger's climate control switch 12P connector terminal No. 1.
Is there battery voltage?
YES -
Go to step 7.
NO -
Repair an open in the wire between the passenger's climate control switch and the No. 16 (7.5 A) fuse in the driver's under-dash fuse/relay box.�
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 an 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 passenger's climate control switch 12P connector terminals No. 7, No. 8, No. 9, No. 10, No. 11, and No. 12 individually.
Is there continuity?
YES -
Repair a 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.�
11. Turn the ignition switch to LOCK (0).
12. Disconnect the driver's climate control switch 16P connector.
13. Turn the ignition switch to ON (II).
14. Measure the voltage between body ground and the driver's climate control switch 16P connector terminal No. 11.
Is there battery voltage?
YES -
Go to step 15.
NO -
Repair an 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.�
15. Turn the ignition switch to LOCK (0).
16. Check for continuity between body ground and driver's climate control switch 16P connector terminal No. 14.
Is there continuity?
YES -
Go to step 17.
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 Harness Locations.�
17. Disconnect climate control unit connector A (28P).
18. Check for continuity between driver's climate control switch 16P connector terminal No. 13 and climate control unit connector A (28P) terminal No. 28.
Is there continuity?
YES -
Go to step 19.
NO -
Repair an open in the wire(s) between the driver's climate control switch and the climate control unit.�
19. Check for continuity between driver's climate control switch 16P connector terminals No. 13 and No. 14.
Is there continuity?
YES -
Repair a short to another wire.�
NO -
Go to step 20.
20. Reconnect the driver's climate control switch 16P connector.
21. Reconnect climate control unit connector A (28P).
22. Press and hold the FAN UP button and OFF button ('08-09 models) or ON/OFF button ('10 model) while holding the buttons, then turn the ignition switch to ON (II).
23. Check the recirculation button LED.
Is the LED blinking?
YES -
Go to step 24.
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 Climate Control Unit Removal/Installation (With Navigation).�
24. Check the recirculation button LED and the AUTO button LED.
Are the LEDs blinking?
YES -
Driver's climate control switch is faulty, replace the driver's climate control switch.�
NO -
Go to step 25.
25. Check the recirculation button LED and the DUAL button LED ('08-09 models) or the SYNC button LED ('10 model).
Are the 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 Climate Control Unit Removal/Installation (With Navigation).�
NO -
Check for loose wires or poor connections at climate control unit and driver's climate control switch. If the connections are good, replace the climate control unit Climate Control Unit Removal/Installation (With Navigation).�