Sensor Function and TCC Operation

Both sensors are negative temperature coefficient thermistors that provide transmission fluid temperature information to the PCM. The PCM sends a 5-volt reference signal to the sensors and measures the voltage drop in the circuit. The internal resistance of the sensors changes as the operating temperature of the transmission fluid changes. The PCM then uses this information to determine when to engage or disengage the TCC.
The PCM inhibits TCC operation until the transmission fluid temperature reaches approximately 45° C (113° F). At this temperature the PCM allows the TCC to engage, if the throttle position, gear range and other vehicle operating conditions are appropriate.