( TL19E00K733000Y1228FAAT00 )

DTC Troubleshooting: B1228 (D and AUTO)

1. Check for continuity between heater control unit connector A (28P) No. 24 terminal and heater control unit connector B (12P) No. 10 terminal.

Is there continuity?

YES | - | Repair short in the wires between the heater control unit and the outside air temperature sensor.■
NO | - | Substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■