Is there continuity?
YES -
Go to step 9.
NO -
Repair an open in the wire(s) between the climate control unit and the A/C pressure sensor.?
9. Reconnect climate control unit connector A (40P).
10. Turn the ignition switch to ON (II).
11. Measure the voltage between climate control unit connector A (40P) terminals No. 6 and No. 8, and between climate control unit connector A
(40P) terminals No. 8 and No. 26.
Is there about 5 V?
YES -
Replace the A/C pressure sensor.?
NO -
Check for loose wires or poor connections at climate control unit connector A (40P) and at the A/C pressure sensor 3P connector. 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 See: Heating and Air Conditioning/Control Assembly/Service and Repair/Climate Control Unit Removal/Installation.?
Short
DTC Troubleshooting: B2980 (B and WINDSHIELD DEFROST)
DTC B2980 or DTC indicator B and WINDSHIELD DEFROST:
A Short in the A/C Pressure Sensor Circuit
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 or the climate control unit.