The Transmission Fluid Pressure Sensor (TFP) is responsible for measuring the transmission pressure and converting it into a voltage signal that is sent to the PCM (Powertrain Control Module). This signal is used by the vehicle’s computer to determine the transmission pressure when shifting occurs.
If input “B” of the TFP Sensor circuit is not within the levels allowed by the manufacturer, the diagnostic code P0847 OBDII is stored. This code, while partly indicative of electrical problems, can also be set for mechanical transmission failures. You should consult your vehicle’s data source for the particular “B” circuit.