B2980

DTC Troubleshooting: B2980 or Indicator 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 DTC with the HDS.

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

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

4. Check for DTCs.

Is DTC B2980 or B and WINDSHIELD DEFROST indicated?
YES - Go to step 5.

NO - Intermittent failure.


5. Check for DTCs.

Are these DTCs also present; B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B1245 or G, and/or B2968 or A and WINDSHIELD DEFROST?
YES - Go to step 16.

NO - Go to step 6.


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

7. Disconnect the A/C pressure sensor 3P connector.

8. Disconnect climate control unit connector A (40P).

9. Check for continuity between body ground and climate control unit connector A (40P) terminal No. 26.

Is there continuity?
YES - Repair short to body ground in the wire between the climate control unit and the A/C pressure sensor.

NO - Go to step 10.






10. Check for continuity between climate control unit connector A (40P) terminals No. 6 and No. 26.

Is there continuity?
YES - Repair the short in the wires.

NO - Go to step 11.






11. Turn the ignition switch to ON (II), and measure the voltage between body ground and climate control unit connector A (40P) terminal No. 26.

Is there any voltage?
YES - Repair short to power in the wire between the climate control unit and the A/C pressure sensor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit.

NO - Go to step 12.






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

13. Reconnect climate control unit connector A (40P).

14. Turn the ignition switch to ON (II).

15. 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.






16. Turn the ignition switch to LOCK (0), and disconnect climate control unit connector A (40P).

17. Disconnect these items:
- Driver's air mix control motor

- Passenger's air mix control motor

- Rear air mix control motor

- Humidity/in-car temperature sensor

- A/C pressure sensor

18. Check for continuity between climate control unit connector A (40P) terminal No. 6 and body ground.

Is there continuity?
YES - Repair short to body ground in the wire.

NO - Go to step 19.






19. Turn the ignition switch to ON (II), and check the same terminal for voltage to body ground.

Is there any voltage?
YES - Repair short to power in the wire. This short may have also damaged the climate control unit. Repair the short to power before replacing the climate control unit.

NO - Go to step 20.






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

21. Reconnect climate control unit connector (40P).

22. Turn the ignition switch to ON (II), and measure the voltage between climate control unit connector A (40P) terminal No. 6 and body ground.

Is there about 5 V?
YES - Go to step 23.

NO - Check for a loose wire or poor connection at climate control unit connector A (40P). If the connection is good, substitute a known-good climate control unit and recheck. If the symptom/indication goes away, replace the original climate control unit.






23. While checking the same terminal for voltage to ground, reconnect these items individually and note the voltage reading each time:
- Driver's air mix control motor

- Passenger's air mix control motor

- Rear air mix control motor

- Humidity/in-car temperature sensor

- A/C pressure sensor

Does the voltage remain at about 5 V?
YES - Substitute a known-good climate control unit and recheck. If the symptom/indication goes away, replace the original climate control unit.

NO - Replace the component that caused the voltage drop.