B2981

DTC B2981 or NAVI communication error is indicated:
Climate Control Unit Lost Communication with Navigation Unit

1. Clear the DTC with the HDS.
2. Operate the climate control system in several modes.
3. Check for DTCs using the HDS or self-diagnostic.

Is DTC B2981 or NAVI communication error indicated?

YES - Go to step 4.

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

4. Turn the ignition switch OFF.
5. Disconnect navigation unit connector A (20P).
6. Disconnect the climate control unit 40P connector.




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

Is there continuity?

YES - Go to step 8.

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




8. Check for continuity between the No. 6, No. 7 and No. 8 terminals of the climate control unit 40P connector and body ground individually.

Is there continuity?

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

NO - Go to step 9.




9. Check for continuity between the terminals of the climate control unit 40P connector.

Is there continuity between any of the terminals?

YES - Repair the short in the wires.

NO - Check for loose wires or poor connections at the climate control unit 40P connector and at navigation unit connector A (20P). If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. If the symptom/indication continues, substitute a known-good navigation unit, and recheck. If the symptom/indication goes away, replace the original navigation unit.