A/T - No Shift/Scanner Reports Shifting
TECHNICAL BULLETIN # 317DATE: 1995
TRANSMISSION: 4L80-E
SUBJECT: No shifting, scanner reports shifting
APPLICATION: GM
4L80-E Scanner Reports Shifting But Transmission Does Not Shift
A condition where no upshifts occurs, but a scanner report shows that the computer is shifting the transmission, can be caused by a broken or leaking actuator feed screen.
When this screen breaks or leaks, solenoid feed oil is drained into the sump. This will result in second gear only. The part number for the screen is 8661709.