With Climate Control

DTC Troubleshooting: B2980 (M and AUTO)

DTC B2980 or DTC indicator M and AUTO:

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.

4. Check for DTCs.

Is DTC B2980 or M and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure.

5. Check for DTCs.

Are these DTCs also present; B1234 or C and WINDSHIELD DEFROST, and/or B1237 or F and WINDSHIELD DEFROST, and/or B1245 or J and WINDSHIELD DEFROST, and/or B2968 or P and AUTO?

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 (36P).

9. Check for continuity between body ground and climate control unit connector A (36P) terminal No. 23.





Is there continuity?

YES -

Repair a 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 (36P) terminals No. 2 and No. 23.





Is there continuity?

YES -

Repair a short in the wire(s).

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 (36P) terminal No. 23.





Is there any voltage?

YES -

Repair a 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 a 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 (36P).

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

15. Measure the voltage between climate control unit connector A (36P) terminal No. 5 and No. 2, and climate control unit connector A (36P) terminals No. 5 and No. 23 individually.





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 (36P) 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 Climate Control Unit Removal/Installation.

16. Turn the ignition switch to LOCK (0), and disconnect climate control unit connector A (36P).

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 (36P) terminal No. 2 and body ground.





Is there continuity?

YES -

Repair a 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 a short to power in the wire. This short may have also damaged the climate control unit. Repair a 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 A (36P).

22. Turn the ignition switch to ON (II), and measure the voltage between climate control unit connector A (36P) terminal No. 2 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 (36P). 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 Climate Control Unit Removal/Installation.

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 Climate Control Unit Removal/Installation.

NO -

Replace the component that caused the voltage drop.