Short
DTC Troubleshooting: B2980 (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 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 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 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 (40P) terminals No. 6 and No. 26.
Is there continuity?
YES -
Repair a 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 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 (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 Climate Control Unit Removal/Installation.�
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 a short to body ground in the wire.�
NO -
Go to step 19.
19. Turn the ignition switch to ON (II), and measure the voltage between the same terminal and 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 (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 Climate Control Unit Removal/Installation.�
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
- 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.�