B2981

DTC Troubleshooting: B2981

DTC B2981: Climate Control Unit Lost Communication with Navigation Unit

1. Clear the DTC with the HDS.

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

3. Do the self-diagnostic function with the HDS. Initial Inspection and Diagnostic Overview

4. Check the DTCs.

Is DTC B2981 indicated?
YES - Go to step 5.

NO - Intermittent failure, check for loose wires or poor connections on the navigation unit and climate control unit circuit.


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

6. Disconnect navigation unit connector A (20P).

7. Disconnect climate control unit connector A (40P).

8. Check for continuity between the following terminals of climate control unit connector A (40P) and navigation unit connector A (20P).





Is there continuity?
YES - Go to step 9.

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






9. Check for continuity between body ground and navigation unit connector A (20P) terminals No. 4, No. 14, and No. 15 individually.

Is there continuity?
YES - Repair short to body ground in the wire(s) between the climate control unit and the navigation unit.

NO - Go to step 10.






10. Check for continuity between navigation unit connector A (20P) terminals as follows.





Is there continuity between any of the terminals?
YES - Repair the short in the wires.

NO - Substitute a known-good navigation unit, and recheck. If the symptom goes away, replace the original navigation unit. If the symptom remains, substitute a known-good climate control unit and recheck. If the symptom goes away, replace the original climate control unit.