Fault code P0717 OBD2 indicates that the Powertrain Control Module (PCM) has not detected voltage output from the input speed sensor (ISS) circuit or the Turbine Speed Sensor (TSS), which has been designated as A. The design of the input speed sensor (ISS) and the Turbine Speed Sensor (TSS) is similar and its function is the same, although the terminology varies to describe them.
The TSS and ISS are 3-wire electromagnetic sensors, and they are used to monitor the input speed of the transmission. This speed is identified by the Powertrain Control Module (PCM) as Revolutions Per Minute (RPM). The sensor is usually located on a bolt directly in the gearbox near the back of the hood housing. The slots are specially made to be attached to the main shaft of the transmission. With this, as the RPM passes from the engine to the transmission, the input shaft rotates and passes very close to the end of the sensor.
The input shaft completes an electromagnetic circuit. This circuit is interrupted as the slots pass through the sensor, forming an electronic pattern. This pattern is received by the PCM as a waveform that is programmed as the input/transmission turbine speed.
To establish the input RPM speed you want to get, a comparison is made of the input speed or transmission turbine speed with the engine RPM speed, the engine load percentage, and the transmission output speed. If the actual inlet/turbine speed or system circuit voltage does not match the desired inlet/turbine speed or voltage is not within the manufacturer’s specifications the diagnostic code P0717 OBDII is set.