HVAC Switch Communication Line Circuit Troubleshooting

HVAC Switch Communication Line Circuit Troubleshooting

1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

2. Disconnect audio-navigation and HVAC switch panel connector A (20P) or audio and HVAC switch panel connector A (20P).

3. Check for continuity between audio-navigation and HVAC switch panel connector A (20P) or audio and HVAC switch panel connector A (20P) terminal No. 3 and body ground.

Is there continuity?

YES -

Go to step 4.

NO -

Check for an open in the wire between the audio-navigation and HVAC switch panel or the audio and HVAC switch panel and body ground. If the wire is OK, check for poor body ground at G501.�

4. If the following switches do not work, go to the step indicated below respectively.

- DRIVER'S SIDE MODE CONTROL button, go to step 5.
- DRIVER'S SIDE TEMPERATURE CONTROL switch, go to step 5.
- DRIVER'S SIDE AUTO button, go to step 5.
- PASSENGER'S SIDE MODE CONTROL button, go to step 16.
- PASSENGER'S SIDE TEMPERATURE CONTROL switch, go to step 16.
- PASSENGER'S SIDE AUTO button, go to step 16.
- FAN ON/OFF button, go to step 27.
- FAN CONTROL button, go to step 27.
- SYNC button, go to step 27.
- WINDSHIELD DEFROST button, go to step 38.
- RECIRCULATION button, go to step 38.
- AIR CONDITIONING button, go to step 38.
- REAR WINDOW DEFOGGER/MIRROR DEFOGGER button, go to step 38.

5. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

6. Measure the voltage between climate control unit connector B (24P) terminals and body ground as shown.

Is there about 5 V?

YES -

Go to step 7.

NO -

Go to step 11.

7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

8. Disconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

9. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

10. Measure the voltage between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown.

Is there about 5 V?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

11. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

12. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

13. Check for continuity between climate control unit connector B (24P) terminals and body ground as shown.

Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

NO -

Go to step 14.

14. Reconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

15. Check for continuity between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown. Do not press the switch or the button.

Is there continuity?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Service and Repair.�

16. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

17. Measure the voltage between climate control unit connector B (24P) terminals and body ground as shown.

Is there about 5 V?

YES -

Go to step 18.

NO -

Go to step 22.

18. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

19. Disconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

20. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

21. Measure the voltage between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown.

Is there about 5 V?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

22. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

23. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

24. Check for continuity between climate control unit connector B (24P) terminals and body ground as shown.

Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

NO -

Go to step 25.

25. Reconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

26. Check for continuity between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown. Do not press the switch or the button.

Is there continuity?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Service and Repair.�

27. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

28. Measure the voltage between climate control unit connector B (24P) terminals and body ground as shown.

Is there about 5 V?

YES -

Go to step 29.

NO -

Go to step 33.

29. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

30. Disconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

31. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

32. Measure the voltage between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown.

Is there about 5 V?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

33. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

34. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

35. Check for continuity between climate control unit connector B (24P) terminals and body ground as shown.

Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

NO -

Go to step 36.

36. Reconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

37. Check for continuity between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown. Do not press the switch or the button.

Is there continuity?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Service and Repair.�

38. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

39. Measure the voltage between climate control unit connector B (24P) terminals and body ground as shown.

Is there about 5 V?

YES -

Go to step 40.

NO -

Go to step 44.

40. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

41. Disconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

42. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

43. Measure the voltage between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown.

Is there about 5 V?

YES -

Substitute a known-good audio-navigation and HVAC switch panel or the audio and HVAC switch panel, and recheck. If the symptom goes away, replace the original audio-navigation and HVAC switch panel Audio-Navigation and HVAC Switch Panel Removal/Installation or the audio and HVAC switch panel Audio and HVAC Switch Panel Removal/Installation.�

NO -

Repair an open in the wires between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

44. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

45. Disconnect climate control unit connector B (24P) and audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

46. Check for continuity between climate control unit connector B (24P) terminals and body ground as shown.

Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the audio-navigation and HVAC switch panel or the audio and HVAC switch panel.�

NO -

Go to step 47.

47. Reconnect audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P).

48. Check for continuity between audio-navigation and HVAC switch panel connector B (32P) or audio and HVAC switch panel connector B (32P) terminals and body ground as shown. Do not press the switch or the button.