For 1990-2009 cars

Check | Causes
--- | ---
DEFINITION: A large engine RPM increase is noted in first gear, Drive range, with little or no vehicle forward speed increase. Second, third, and fourth gear operation are normal. Shifts into first gear are soft or do not occur.
Control Valve Body Accumulator Assembly |

• | 1-2 shift control valve stuck released

• | 1-2 shift valve stuck released

• | A stuck ON SS valve

Forward and Low Clutch Sprag |

• | Damaged sprag

• | Worn or pitted inner race

Forward Clutch Assembly | Damaged