P0717 - INPUT / TURBINE SPEED SENSOR A CIRCUIT NO SIGNAL

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.

• The Check Engine light on the dashboard is on.
• The speedometer may be running intermittently.
• When the transmission makes changes, it may be difficult or abrupt.
• The transmission may not make all the changes.
• The fuel may not be efficient.

If the code P0717 has been set, it means that one or more of the following faults have occurred:

• The cables or connectors in the Input Speed Sensor (ISS) circuit may be defective or worn.
• The input speed sensor (ISS) may be defective.
• There may be a Powertrain Control Module (PCM) programming error.

In case the DTC P0717 is established, you can do the following:

• First of all, you might want to review your vehicle's technical service bulletins (TBS) since your problem may be known, as well as the solution.
• Check the wiring of the system as well as its respective connectors. The circuit may be shorted, or water may be present in the connector. Repair or replace any of these components as necessary.
• Check the battery, its cables, as well as the alternator output.
• By using a DVOM, check that there are 5 volts reference and 0 volts ground on each of its circuits. If you find problems, you can make the same checks in the TCM (Transmission Control Module). Note that the Turbine Speed Sensor (TSS) can be checked through a back check on the TCM (Transmission Control Module) and test the vehicle's drive, the voltage should rise with engine speed. This continuity check should be done with both the TCM and the TSS sensor disconnected, to avoid damage to the TCM. Repair the fault as necessary.
• If you don't find problems in the circuit, you should use a more advanced diagnostic tool, such as a digital oscilloscope, and test the TSS sensor connector that goes into the Transmission Control Module (TCM) on a test drive. You should compare the engine RPM between the CKP sensor (Crankshaft Position Sensor) and the TSS sensor (Turbine Speed Sensor). The signal should increase and decrease according to the engine If there is a fault with the signal, which may have voltage changes, you must check the wiring system before changing the TSS sensor.
• Change the TSS