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 Initial Inspection and Diagnostic Overview.

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 Initial Inspection and Diagnostic Overview or the climate control unit Initial Inspection and Diagnostic Overview.

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.�