( TF09E8HK711000Y1226FAAT00 )
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 DTC with the HDS.
  1. Turn the ignition switch to LOCK (0), and then to ON (II).
  1. Check for DTCs.
Is DTC B1226 or B and AUTO indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure.■
  1. Turn the ignition switch to LOCK (0).
Is the in-car temperature sensor OK?
YES -
Go to Step 7 .
NO -
Replace the humidity/in-car temperature sensor .■
  1. Disconnect the climate control unit 36P connector.
  1. Check for continuity between body ground and the climate control unit 36P connector No. 1 and No. 20 terminals individually.
Is there continuity?
YES -
Repair short to body ground in the wires between the climate control unit and the in-car temperature sensor.■
NO -
Go to Step 9 .
  1. Check for continuity between the climate control unit 36P connector No. 1 and No. 20 terminals.
Is there continuity?
YES -
Repair short in the wires between the climate control unit and the in-car temperature sensor.■
NO -
Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit .■