B2979

DTC B2979 or PRE sensor open is indicated.:
An Open in the A/C Pressure Sensor Circuit

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 B2979 or PRE sensor open indicated?

YES - Go to step 4.

NO - Intermittent failure, check for loose wires or poor connections on the A/C pressure sensor circuit.

4. Turn the ignition switch OFF.
5. Disconnect the A/C pressure sensor 3P connector.
6. Disconnect the climate control unit 40P connector.




7. Check for continuity between the given terminals of the climate control unit 40P connector and the A/C pressure senior 3P connector.

Is there continuity?

YES - Go to step 8.

NO - Repair any open in the wire(s) between the climate control unit and the A/C pressure sensor.

8. Check for proper A/C system pressure.

Is the pressure within specifications?

YES - Check for loose wires or poor connections at the climate control unit 40P connector and at the A/C pressure sensor 3P connector. If the connections are good, replace the A/C pressure sensor. If the symptom/indication continues, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

NO - Repair the A/C pressure problem.