Can the input speed sensor on a 2009 GMC Acadia be changed without having to remove the transmission

Did you do the diagnostic's that go to that code ?
DTC P0717: Input Speed Sensor Circuit Low Voltage
Diagnostic Fault Information
Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance
Input Speed Sensor Supply Voltage
P0717
P0717
--
P0716
Input Speed Sensor Signal
P0716, P0717
P0716, P0717
P0716, P0717
P0716
Circuit/System Description
The input speed sensor (ISS) is a hall-effect type sensor. The sensor faces the 1-2-3-4 and 3-5-R clutch housing machined teeth surface. The sensor receives 8.3-9.3 volts on the input/output speed sensor (ISS/OSS) supply voltage circuit from the transmission control module (TCM). As the 1-2-3-4 and 3-5-R clutch housing rotates, the sensor produces a signal frequency based on the machined surface of the 1-2-3-4 and 3-5-R clutch housing. This signal is transmitted through the ISS signal circuit to the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly uses the ISS signal to determine line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.

Circuit/System Verification
Engine idling, observe the scan tool Transmission ISS parameter while varying the engine speed. The Transmission ISS parameter should change with the engine speed and not drop out.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Ignition OFF, remove the control valve body cover. Refer to Control Valve Body Cover Replacement.
Connect the TCM harness connector.
Disconnect the input speed sensor (ISS) from the control solenoid (w/body and TCM) valve assembly.
Connect the J 38522 between the supply voltage terminal B and ISS signal terminal A at the control solenoid (w/body and TCM) valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Input Shaft Speed/Output Shaft Speed Input Test for further instructions.
Set the J 38522 signal to 8 volts, the frequency to 120 and the percent duty cycle to 50.
Ignition ON, observe the scan tool Transmission ISS parameter. The scan tool Transmission ISS parameter should be between 100-400 RPM.
? If not within the specified range, replace the control solenoid (w/body and TCM) valve assembly.
If all circuits test normal, test or replace the input speed sensor.

Control Valve Body Cover Replacement

Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement.
Remove the oil cooler inlet hose (1) from the retainer on the control valve body cover.
Remove the oil cooler outlet hose retainer nut (5) from the control valve body cover.
Remove the oil cooler outlet hose (4) from the retainer on the control valve body cover.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Remove the left engine splash shield. Refer to Engine Splash Shield Replacement.
Drain the transmission. Refer to Transmission Fluid Replacement.

you don't need to pull thr trans .