DTC B1412/12 Ambient Temperature Sensor Circuit: Description

The ambient temperature sensor is installed in the front part of the condenser to detect the ambient temperature and control the air conditioner "AUTO" mode. The sensor connected to the front light ECU (front controller) detects fluctuations in the ambient temperature. This data is used for controlling the room temperature. The sensor sends a signal to the air conditioning amplifier via the front light ECU (front controller). The resistance of the ambient temperature sensor changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The front light ECU (front controller) applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes. The front light ECU (front controller) sends the read signal to the air conditioning amplifier via the CAN communication line.

HINT:

This circuit uses the CAN communication line. Before performing the inspection, check that the CAN communication system is functioning normally.