Check for loose wires or poor connections at climate control unit connector A (40P) 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 See: Heating and Air Conditioning/Control Assembly/Service and Repair/Climate Control Unit Removal/Installation.?
NO -
Repair an open in the wire between the climate control unit and the in-car temperature sensor.?
B1226
DTC Troubleshooting: B1226 (B and AUTO)
DTC B1226 or DTC indicator B and AUTO:
A Short in the In-Car Temperature 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 B1226 or B and AUTO indicated?
YES -
Go to step 5.
NO -
Intermittent failure, check for loose wires or poor connections in the in-car temperature sensor circuit.?
5. Turn the ignition switch to LOCK (0).
6. Remove the humidity/in-car temperature sensor See: Heating and Air Conditioning/Cabin Temperature Sensor / Switch/Service and Repair,
and test it.
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 See: Heating and Air Conditioning/Cabin Temperature Sensor / Switch/Service and Repair.?
7. Disconnect climate control unit connector A (40P).
8. Check for continuity between climate control unit connector A (40P) terminal No. 5 and body ground.
Is there continuity?
YES -
Repair a short to body ground in the wire between the climate control unit and the in-car temperature sensor.?
