( TL19E00K733000Y1241FAAT00 )

DTC Troubleshooting: B1241 (N and A/C ON)

1. Measure the voltage between body ground and heater control unit connector B (12P) No. 5 and No. 6 terminals individually.

Is there voltage?

YES | - | Repair short to power in the wire(s).■
NO | - | Go to Step 22 .

1. Turn the ignition switch to LOCK (0).

1. Reconnect heater control unit connector B (12P).

1. Test the power transistor.

Is the power transistor OK?

YES | - | Check for loose wires or poor connections at heater control unit connector B (12P) and at the power transistor 4P connector. If the connections are good, substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■
NO | - | Replace the power transistor.■

1. Disconnect the jumper wire.

1. Disconnect the blower motor 2P connector.