Monitoring The Substrate Temperature Sensor
The TCM is situated within the transmission on the valve body. As the TCM controls a number of high power solenoids and is surrounded by ATF, the TCM can obviously get very hot. If the temperature of the hardware rises above a pre-determined level the TCM will be shut down. Prior to the TCM shutting down the TCM will log a fault code, during shutdown the transmission will enter mechanical limp-home mode. Monitoring of the substrate temperature is performed by a temperature dependent resistor mounted on the processor.