( TL19E00K733000Y1240FAAT00 )

DTC Troubleshooting: B1240 (J and A/C ON)

DTC B1240 or DTC indicator J and A/C ON:
A Problem in the Mode Control Linkage, Doors, or Motor Circuit

1. Turn the ignition switch to LOCK (0) and then to ON (II).

1. Do the self-diagnostic function with the HDS or the heater control unit.

1. Check for DTCs.

Is DTC B1240 or J and A/C ON indicated?

YES | - | Go to Step 4 .
NO | - | Intermittent failure, check for loose wires or poor connections on the mode control motor circuit.■

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

1. Test the mode control motor.

Is the mode control motor OK?

YES | - | Go to Step 6 .
NO | - | Replace the mode control motor, or repair the mode control linkage or doors.■

1. Disconnect the mode control motor 7P connector.

1. Disconnect heater control unit connector A (28P).

1. Check for continuity between the following terminals of heater control unit connector A (28P) and the mode control motor 7P connector.

   28P: | 7P:
   --- | ---
   No. 7 | No. 2
   No. 8 | No. 1

Is there continuity?

YES | - | Go to Step 9 .
NO | - | Repair open in the wire(s) between the heater control unit and the mode control motor.■

1. Check for continuity between body ground and heater control unit connector A (28P) No. 7 and No. 8 terminals individually.

Is there continuity?

YES | - | Repair short to body ground in the wire(s) between the heater control unit and the mode control motor.■
NO | - | Substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit .■