Circuit Description

The automatic transmission fluid (ATF) temperature sensor converts the fluid temperature into a resistance value which is input into the engine control module (ECM). Based on the resistance, the ECM determines the ATF temperature and detects opens or shorts in the ATF temperature circuit.

After running the vehicle for a certain period, the ATF temperature should increase. When the ATF temperature is below 10°C (50°F), or when the ATF temperature is 100°C (212°F) or more and the engine coolant temperature reaches 60°C (140°F) after engine cold start, the ECM interprets this as a fault, illuminates the MIL and stores the DTC.