GM Service Manual Online
For 1990-2009 cars only

Check

Causes

DEFINITION: A large engine RPM increase and forward vehicle speed decrease do not immediately occur when the transmission is shifted from Overdrive or fourth gear in Drive range to either first or second gear, manual second.

Control Valve Body Accumulator Assembly

    • 3-4 shift valve stuck released
    • Missing or stuck low pressure control valve
    • 4-5 shift valve and/or 4-5 control shift valve stuck released
    • 1-2 shift valve stuck released
    • 2-3 shift valve and/or 2-3 control shift stuck released