Is your 48RE transmission shifting poorly in 1-2 gear?
Is it holding 2nd gear to high RPM under light throttle and then slamming 3rd gear?
Is it hunting back and forth from 2 - 3?
These two parts are likely the cause on the 48RE.
Okay, here's what you need to do first....
1 - Go to the dealer and make them hook up the StarScan. Tell them to set it up to DISPLAY and RECORD the REQUESTED and ACTUAL pressures for the governor solenoid. It makes it easier to see rather than seeing it from the passenger seat.
2 - Go for a drive so that you can go through all the gears on the tranny.
3 - You're looking for the following pressures from the Governor Solenoid. If the pressures aren't close to these, the sensor and solenoid need to be replaced.
1 - 2 Shift: ~28 psi
2 - 3 Shift: ~50 psi
3 - 4 Shift: ~95 - 128 psi (based on throttle position)
4 - To replace the Governor Solenoid and Governor Solenoid Pressure Sensor, follow the steps below.
Drain the tranny and remove the pan.....
Remove the filter. These are two T15 or T20 Torx head screws.....
Now we can see the two items that need to be replaced.....
Remove the bolts that secure the bracket that holds the sensor and solenoid.....
Remove the bracket. Just wiggle it out.....
Remove the two connectors that go to the sensor and solenoid.....
Pop the senor and solenoid out. They simply pull out at this point.....
To put it back together, just reverse the process.
