HVAC - With Climate Control

DTC Troubleshooting: B1240 (B)

DTC B1240 or DTC indicator B:

A Problem in the Mode Control Linkage, Doors, or Motor

NOTE: If DTC B1240 is detected with HDS, it is not necessary to do step 1.

1. Check the sensor input display mode, and select "mode motor" according to the table.

NOTE: This indication by segment lit on digital segments is assigned for 2 failure causes that it is necessary to decide which one is a true cause. If there is a failure in the sensor or motor, a value corresponded to the sensor or motor in the Sensor Input Display Mode is displayed as "Er", which serves to specify which is a true cause.

Is sensor value indicated "Er"?

YES -

Go to step 2

NO -

Go to troubleshooting DTC B1226 or DTC indicator B B1226

2. Clear the DTC with the HDS.

3. Turn the ignition switch to LOCK (0), and then back to ON (II).

4. Do the self-diagnostic with the HDS or the climate control unit.

5. Check for DTCs.

Is DTC B1240 or B indicated?

YES -

Go to step 6.

NO -

Intermittent failure. Check for loose wires or poor connections on the mode control motor circuit.�

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

7. Test the mode control motor Mode Control Motor Test.

Is the mode control motor OK?

YES -

Go to step 8.

NO -

Replace the mode control motor Mode Control Motor Replacement, or repair the mode control linkage or doors.�

8. Disconnect the mode control motor 7P connector.

9. Disconnect climate control unit connector A (24P).

10. Check for continuity between the following terminals of climate control unit connector A (24P) and the mode control motor 7P connector.









Is there continuity?

YES -

Go to step 11.

NO -

Repair an open in the wire(s) between the climate control unit and the mode control motor.�

11. Check for continuity between body ground and climate control unit connector A (24P) terminals No. 7 and No. 8 individually.





Is there continuity?

YES -

Repair a short to body ground in the wire(s) between the climate control unit and the mode control motor.�

NO -

Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�