Shift Accumulation
WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
1-2/3-4 Accumulator Valves
Line pressure is regulated into accumulator fluid pressure. Torque signal fluid pressure acting on the end of the valve basically controls this regulation.
1-2, and 3-4 Accumulator Assemblies
Accumulator fluid is routed to each of the accumulator assemblies in preparation for upshifts. The fluid which is routed to the 1-2 and to the 3-4 accumulators is orificed by the #4 and the #7 checkballs. The 2-3 accumulator fluid circuit does not use a checkball in order to orifice accumulator fluid to the 2-3 accumulator.