DTC P0121: Throttle Position Sensor Circuit Range/Performance: Operation
A 5-volt power supply is applied on the TP sensor power terminal (terminal No. 1) from the PCM (terminal No. 46). The ground terminal (terminal No. 4) is grounded with PCM (terminal No. 57). When the throttle valve shaft is turned from the idle position to the fully opened position, the resistor between the TP sensor output terminal (terminal No. 2) and ground terminal will increase according to the rotation. See Fig 1 .