B2978

DTC Troubleshooting: B2978 or PaVENT sensor short is indicated

DTC B2978 or PaVENT sensor short is indicated: A Short in the Passenger's Vent Air Temperature Sensor Circuit

1. Clear the DTC with the HDS.

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

3. Do the self-diagnostic with the HDS Initial Inspection and Diagnostic Overview or the climate control unit. Initial Inspection and Diagnostic Overview

4. Check for DTCs.

Is DTC B2978 or PaVENT sensor short indicated?
YES - Go to step 5.

NO - Intermittent failure. Check for loose wires or poor connections on the passenger's vent air temperature sensor circuit.


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

6. Remove the passenger's vent air temperature sensor Passenger's Vent Air Temperature Sensor Replacement and test it. Vent Air Temperature Sensor Test

Is the passenger's vent air temperature sensor OK?
YES - Go to step 7.

NO - Replace the passenger's vent air temperature sensor.


7. Disconnect the climate control unit 40P connector.

8. Check for continuity between body ground and climate control unit 40P connector terminal No. 37.

Is there continuity?
YES - Repair a short to body ground in the wire between the climate control unit and the passenger's vent air temperature sensor.

NO - Go to step 9.






9. Check for continuity between climate control unit 40P connector terminals No. 33 and No. 37.

Is there continuity?
YES - Repair a short in the wires between the climate control unit and the passenger's vent air temperature sensor.

NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. Service and Repair