Throttle/Pedal Position Sensors

This system is equipped with a redundant sensor system. These sensors are located on throttle body. There are 2 Throttle Position (TP) sensors, and 2 Pedal Position (PP) sensors. The TP sensor are connected to throttle spindle. When throttle position increases, TP sensor No. 1 voltage increases, TP sensor No. 2 voltage decreases, PP sensor No. 1 voltage decreases and PP sensor No. 2 voltage increases. These sensors are used to compare requested throttle position with actual throttle position. One sensor returns a low reference voltage at idle while other sensor returns a high reference voltage (around 5 volts). At wide open throttle, sensor values are reversed. The 2 voltage signals are combined and are inputted to ECM. Voltage from TP sensor No. 1 is used by ECM as a value for current throttle position. Voltage from PP sensor No. 1 is used by ECM to measure driver's torque request. Return voltage (the sum of both PP sensors or TP sensors) should always be around 5 volts. If voltage is not as specified, a Diagnostic Trouble Code (DTC) will set, and throttle control will go into limp-home mode (throttle angle is no longer controlled by ECM). A sprocket spring loaded by the throttle arm return spring will release the throttle arm return spring when the limp-home solenoid is activated. This will disengage the throttle control motor and allow throttle operation via redundant accelerator cable. Accelerator pedal feel will not be affected when vehicle is in limp-home mode. The sprocket must be reset manually after repair and clearing of the Diagnostic Trouble Code (DTC). In case of PP sensor malfunction, maximum engine speed will be limited to 2200 RPM.