B2981
DTC B2981 or NAVI communication error is indicated: Climate Control Unit Lost Communication with Navigation Unit1. Clear the DTC with the HDS.
2. Turn the ignition switch OFF and then ON (II).
3. Do the self-diagnostic with the HDS or climate control unit.
4. Check for DTCs.
Is DTC B2981 or NAVI communication error indicated?
YES - Go to step 5.
NO - Intermittent failure, check for loose wires or poor connections on the navigation unit circuit.
5. Turn the ignition switch OFF.
6. Disconnect navigation unit connector A (20P).
7. Disconnect the climate control unit 40P connector.
8. 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 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 the climate control unit 40P connector terminals No. 6, 7, and 8 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 the climate control unit 40P connector terminals as given.
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.