HVAC

DTC Troubleshooting: B2965

DTC B2965:

HVAC Control Unit Lost Communication with Rear HVAC Control Panel

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back to ON (II).

3. Do the self-diagnostic function with the HDS.

4. Check for DTCs.

Is DTC B2965 indicated?

YES -

Go to step 5.

NO -

Intermittent failure, check for loose wires or poor connections in the rear HVAC control panel and HVAC control unit circuit.�

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

6. Disconnect the rear HVAC control panel 12P connector.

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

8. Measure the voltage between rear HVAC control panel 12P connector terminal No. 12 and body ground.





Is there battery voltage?

YES -

Go to step 9.

NO -

Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the rear HVAC control panel.�

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

10. Check for continuity between rear HVAC control panel 12P connector terminal No. 9 and body ground.





Is there continuity?

YES -

Go to step 11.

NO -

Check for an open in the wire between the rear HVAC control panel and body ground. If the wire is OK, check for poor ground at G801.�

11. Disconnect HVAC control unit connector A (24P).

12. Check for continuity between the following terminals of HVAC control unit connector A (24P) terminal No. 10 and rear HVAC control panel 12P connector terminal No. 5.





Is there continuity?

YES -

Go to step 13.

NO -

Repair an open in the wire between the HVAC control unit and the rear HVAC control panel.�

13. Check for continuity between body ground and HVAC control unit connector A (24P) terminal No. 10.





Is there continuity?

YES -

Repair a short to body ground in the wire between the HVAC control unit and the rear HVAC control panel.�

NO -

Substitute a known-good rear HVAC control panel, and recheck. If the symptom/indication goes away, replace the original rear HVAC control panel.�