Transmission issues, code PO717

CONNIE MITCHELL

MEMBER
2002 BUICK CENTURY
3.1L
6 CYL
2WD
AUTOMATIC
175,000 MILES

I have the car listed above custom model. The transmission is not shifting right. It will go into gear to drive but while driving down the road it just revs and will not go any farther. I shut it off and start it back to get it to go in gear. Went to a shop and the only code that came up was PO717. Input speed sensor but the guy sold us an output sensor and said that it was more than likely the problem but that did not work. I need to know where the input sensor is located on my car.

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning.

Before throwing parts at it, have you changed the oil/filter? A clogged filter will cause this issue. The speed sensor will not cause it come out of gear and neutral out.

Roy

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Friday, March 16th, 2018 AT 7:16 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

The input speed sensor may be there because the input shaft was not turning fast enough to send a signal.
The sensor is inside the transmission under the side cover on the drivers side of the trans.

Roy

717 code description

Circuit Description
The automatic transmission input shaft speed (AT ISS) sensor is a permanent magnet with a coil of wire wound around it. The AT ISS sensor mounts in the case cover facing the reluctor wheel of the input shaft. As the reluctor wheel is driven by the turbine shaft, an AC signal is induced in the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage at the sensor.
There is a fixed air gap between the sensor and the teeth on the sensor reluctor wheel. The AT ISS sensor input is used by the PCM in order to control line pressure, TCC apply and release and transmission shift patterns. This sensor is also used to calculate the gear ratios and TCC slippage.
If the PCM detects a low input speed while the vehicle and engine speeds are high, then DTC P0717 sets. DTC P0717 is a type B DTC.

Conditions for Running the DTC
No VSS DTC P0502 or P0503.
No TFP manual valve position switch DTC P1810.
The engine speed is greater than 500 RPM for 5 seconds and not in fuel shut off.
The transmission is not in PARK or NEUTRAL.
The vehicle speed is 8 km/h (5 mph) or greater.

Conditions for Setting the DTC
The input shaft speed is less than 100 RPM for 5 seconds.

Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
The PCM inhibits TCC.
The PCM freezes shift adapts. The PCM inhibits 4th gear if the transmission is in Hot Mode.
The PCM turns ON the MIL in Hot Mode.
The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
The PCM stores DTC P0717 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
A scan tool can clear the MIL/DTC.
The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step checks if the PCM receives a signal from the AT ISS sensor.
3. A Yes answer indicates that the transmission side of the circuit is functioning properly.
4. Although the resistance is within specification in Step 3, there may be a short to ground or a short to power condition.
8. This step begins the transmission harness diagnosi