Circuit/System Description

The TP sensor used with the throttle actuator control (TAC) system is actually a Hall Effect switch. The Hall Effect switch is surrounded by a magnetic yoke that induces a flux in the magnetic field when the throttle shaft is rotated. The PCM provides a 5-volt reference voltage to the sensor circuits in the TAC module. An integrated circuit (IC) receives and converts the magnetic pulses into two separate TP signal, each with their own characteristics. The TP sensor 1 output provides the powertrain control module (PCM) with a signal voltage that is proportional to the throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens. TP sensor 1 determines the actual throttle valve position. TP sensor 2 has a voltage that is greater than twice that of TP sensor 1 at idle. TP sensor 2 provides a backup value for TP sensor 1.