F and Windshield Defrost

DTC Troubleshooting: B2980 or Indicator F and Windshield Defrost

DTC B2980 or DTC indicator F 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 back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.

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 B2980 or F and WINDSHIELD DEFROST indicated?
YES - Go to step 5.

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


5. Check for DTCs.

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

NO - Go to step 6.


6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

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

8. Disconnect climate control unit connector C (20P).

9. Check for continuity between body ground and climate control unit connector C (20P) terminal No. 11.

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 C (20P) terminals No. 2 and No. 11.

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

NO - Go to step 11.






11. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector C (20P) terminal No. 11.

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), or press the engine start/stop button to select the OFF mode.

13. Reconnect climate control unit connector C (20P).

14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

15. Measure the voltage between climate control unit connector C (20P) terminals No. 1 and No. 2, and between climate control unit connector C (20P) terminals No. 1 and No. 11.

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 C (20P) 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), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P).

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

- Passenger's air mix control motor

- Humidity/in-car temperature sensor

- A/C pressure sensor

18. Check for continuity between climate control unit connector C (20P) terminal No. 2 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), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and 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), or press the engine start/stop button to select the OFF mode.

21. Reconnect climate control unit connector C (20P).

22. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) 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 C (20P). 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 measuring the voltage as described in step 22, reconnect these items individually and note the voltage reading each time:
- Driver's air mix control motor

- Passenger's 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.