Got this code after traveling about 200 miles. I replaced the outer sensor but now think it had nothing to do with it. Drove home another 200 miles and the Suburban ran perfect on the highway, speedo OK, cruise control OK. Only symtom is the hard shift from 1st to 2nd other than that it ran fine. Check engine light is on but the problem seemed sporadic. Took off once shifted fine. But still a problem. The new trany is only 6 years old. Any advice would be much appreciated.

 

1. Check the Wiring Harness (Likely)

The wiring harness is going to be where you would want to start looking for P0717’s causes. Check for damaged wiring, particularly where the harness plugs into the input/turbine speed sensor.

Do the pins look corrosion-free? They may need cleaning to make good contact. Use an electrical contact cleaner.

Verify that the ground is solid. If there doesn’t look to be any visible damage, you can verify the voltage with a voltmeter.

Repair the wiring harness as needed.

2. Input Speed Sensor (Very Likely)

Now that you have verified that the wiring going to the input/turbine speed sensor is functioning, it’s likely that the sensor itself is malfunctioning and causing P0717.

If you pull the sensor, verify that there are no metal shavings on its magnetic tip. If there are, that can be enough to disrupt the signal. You can try cleaning the shavings off and seeing the sensor begins to function again.

I hope these solutions can solve your P0717 OBD issues, Hard shifting is common with that code.

 

thanks for the info oilcan, I did replace the outer sensor near the top of the tranny, everything looked clean but with a little more research saw that the "input" speed sensor might be inside the trans.

 

Looks like the transmission is going to have to be pulled to replace the faulty input speed sensor. Great design! Well, it is what it is, I love the Suburban.