NOTE： If all of door motors DTC are detected, check this circuit. 1.CHECK COMMUNICATION SIGNAL

1. Turn the ignition switch ON.
2. Check output waveform between A/C auto amp. harness connector and ground with the oscilloscope.

(+) | (−) | Output waveform
A/C auto amp. | —
Connector | Terminal
M66 | 10 | Ground |

Is the inspection result normal?
YES>>GO TO 3.
NO>>GO TO 2.
2.CHECK COMMUNICATION SIGNAL CIRCUIT FOR SHORT

1. Turn the ignition switch OFF.
2. Disconnect the following connectors;

- A/C auto amp.
- Mode door motor
- Intake door motor
- Air mix door motor (driver side and passenger side)

3. Check continuity between A/C auto amp. harness connector and ground.

   A/C auto amp. | — | Continuity
   Connector | Terminal
   M66 | 10 | Ground | Not existed

Is the inspection result normal?
YES>>Replace A/C auto amp.
NO>>Repair the harnesses or connectors.
3.CHECK COMMUNICATION SIGNAL CIRCUIT FOR OPEN

1. Turn the ignition switch OFF.
2. Disconnect the A/C auto amp. and the mode door motor connectors.
3. Check continuity between A/C auto amp. harness connector and the mode door motor harness connector.

   A/C auto amp. | Mode door motor | Continuity
   Connector | Terminal | Connector | Terminal
   M66 | 10 | M253 | 3 | Existed

Is the inspection result normal?
YES>>Replace A/C auto amp.
NO>>Repair the harnesses or connectors.