No 1-2 Upshift In "D" Position
Low hydraulic pressure, 1-2 accumulator, valve body (1-2 shift valve stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), 2-4 band and servo or low one-way clutch assembly.
Low hydraulic pressure, 1-2 accumulator, valve body (1-2 shift valve stuck or damaged), incorrectly tightened valve body bolts (cross-leaks), 2-4 band and servo or low one-way clutch assembly.