Slips while Shifting

WARNING: This page is about a different car, the 2005 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

Checks	Causes
DEFINITION: A large engine RPM increase is noted in fifth, fourth, third, second or first in Drive range, with little or no vehicle forward speed increase. Shifts into fifth, fourth, third, second or first gear are soft or do not occur.
Control Valve Body Accumulator Assembly	Accumulator piston seals Porosity in the accumulator piston housings Stuck or missing ball check valves
Pressure Control Solenoid	Damaged
Fluid Pump	Damaged