This problem can be a faulty transmission control module,the circuit that connects sensors to the module,or the input speed sensor.
With the use of a scan tool one should be able to see & evaluate the input sensor speed while driving the vehicle.
The transmission control module (TCM) uses the (GMLAN) to signal the engine control module (ECM) that the TCM is requesting malfunction indicator lamp (MIL) illumination. This happens when the TCM has determined that a failure affecting emissions has occurred in transmission control system. When the ECM receives the a message from the TCM, DTC P0700 will set.
Here is some info on what might cause your P0717,inspect before replacing any parts.
PIP4051E: Harsh Shifts MIL Illuminated DTC P0717 Input Speed Sensor (ISS) Circuit Low Voltage - keywords code SES - (Oct 27, 2009)
Subject:Harsh Shifts, MIL Illuminated, DTC P0717 Input Speed Sensor (ISS) Circuit Low Voltage
Models:2006-2007 Buick Rainier
2006-2009 Chevrolet Trailblazer
2007-2010 Chevrolet Avalanche, Colorado, Silverado, Suburban, Tahoe
2006-2009 GMC Envoy
2007-2010 GMC Canyon, Sierra, Yukon, Yukon XL
2007-2010 Hummer H3
2006-2009 Saab 9-7x
Equipped With 4L60E, 4L65E or 4L70E (RPO M30, M32, M70) Automatic Transmission
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Some customers may comment on a harsh shift, illuminated MIL and a DTC P0717 may be found as a history code in the TCM.
Follow current SI diagnostics, if diagnosis of this condition leads to removal of the pump and ISS it is important to visually inspect the condition of the ISS wires. These wires can be damaged in the area where they are exposed and not encased in conduit as shown in the figure below. WPC returns have shown that when wire damage has occurred it is usually the white wire that is damaged. If wire damage is found replace the ISS and inspect the pump cover in same area for any possible sharp points that may cause damage to the wire. Any sharp points on the pump casting in this area should be removed with a file.