DTC Troubleshooting: B1226 (B)
DTC B1226 or DTC indicator B:
 A Short in the In-car Temperature Sensor Circuit
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch OFF and then ON (II).
  1. Check for DTCs.
Is DTC B1226 or B indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure.■
  1. Turn the ignition switch OFF.
Is the in-car temperature sensor OK?
YES -
Go to Step 7 .
NO -
Replace the in-car temperature sensor .■
  1. Disconnect the heater control unit 32P connector.
  1. Check for continuity between body ground and the heater control unit 32P connector terminal No. 14.
Is there continuity?
YES -
Repair short to body ground in the wire between the heater control unit and the in-car temperature sensor.■
NO -
Go to Step 9 .
  1. Check for continuity between the heater control unit 32P connector terminals No. 14 and No. 24.
Is there continuity?
YES -
Repair short in the wires between the heater control unit and the in-car temperature sensor.■
NO -
Substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■