B1225

DTC Troubleshooting: B1225 (A and AUTO)

DTC B1225 or DTC indicator A and AUTO:

An Open in the In-Car Temperature 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 Function with the HDS or the climate control unit.

4. Check for DTCs.

Is DTC B1225 or A and AUTO indicated?

YES -

Go to step 5.

NO -

Intermittent failure. Check for loose wires or poor connections on the in-car temperature sensor circuit.

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

6. Remove the humidity/in-car temperature sensor Service and Repair, and test it Testing and Inspection.

Is the in-car temperature sensor OK?

YES -

With the humidity/in-car temperature sensor disconnected, go to step 7.

NO -

Replace the humidity/in-car temperature sensor Service and Repair.

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

8. Check for continuity between climate control unit connector C (20P) terminal No. 15 and humidity/in-car temperature sensor 4P connector terminal No. 4.





Is there continuity?

YES -

Go to step 9.

NO -

Repair an open in the wire between the climate control unit and the in-car temperature sensor.

9. Check for continuity between climate control unit connector C (20P) terminal No. 1 and humidity/in-car temperature sensor 4P connector terminal No. 3.





Is there continuity?

YES -

Check for loose wires or poor connections at climate control unit connector C (20P) and at the humidity/in-car temperature sensor 4P 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 Service and Repair.

NO -

Repair an open in the wire between the climate control unit and the in-car temperature sensor.