| DTC indicator M or DTC B1240: | A Problem in the Mode Control Linkage, Doors, or Motor |
| 1. | Clear the DTC. |
| 2. | Turn the ignition switch OFF, and then ON. |
| 3. | Operate the climate control system is several modes. |
| 4. | Check the DTCs. Is DTC M or B1240 indicated? YES - Go to 5. NO - Intermittent failure.n |
| 5. | Test the mode control motor. Is the mode control motor and linkage OK? YES - Go to 6. NO - Replace the mode control motor, or repair the mode control linkage or doors.n |
| 6. | Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication varification status Is the communication OK? YES - Substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.n NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.n |