DTC B1412: Ambient Temperature Sensor Circuit [06/2018 - ]: Description

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The thermistor assembly is installed in front of the cooler condenser assembly to detect the ambient temperature, which is used to control the air conditioning system. This sensor is connected to the air conditioning amplifier assembly and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the air conditioning amplifier assembly. The resistance of the thermistor assembly changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the thermistor assembly and reads voltage changes due to changes in the resistance of the thermistor assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Memory
B1412	Ambient Temperature Sensor Circuit	Open or short in ambient temperature sensor circuit	Thermistor assembly Air conditioning amplifier assembly Harness or connector	Memorized (4 sec. or more)*

*: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

HINT:

If the ambient temperature is approximately -52.9°C (-63.22°F) or lower, DTC B1412 may be stored even though the system is normal.