Momentary lock-up at or near idle speeds could be from the P0894 being set & defaulting to Max line pressure.
4L80E's don't have a Lube to Line Bypass from the factory resulting in NO converter feed when the Regulator Valve is at full rest (Max Pressure), This cuts off the pressure that keeps the converter clutch unlocked.
This is one of the reasons why a "Lube to Line Bypass" is drilled in the pump cover.
4L80E's don't have a Lube to Line Bypass from the factory resulting in NO converter feed when the Regulator Valve is at full rest (Max Pressure), This cuts off the pressure that keeps the converter clutch unlocked.
This is one of the reasons why a "Lube to Line Bypass" is drilled in the pump cover.
