(1) Severe wear of the transmission pump, resulting in excessive internal leakage and reduced volumetric efficiency. First, check the pump connections, then inspect the transmission pump itself.
(2) Failure of the pressure regulating spring in the transmission control valve (loss of elasticity or breakage), jamming of the pressure reducing valve stem, or jamming of the accumulator piston, preventing the spring from retracting. Disassemble, inspect, and clean the transmission control valve, or replace any damaged parts.
(3) Oil leakage in the main oil passage or blockage of the oil filter. Inspect and clean.
(4) Damage to the gasket at the interface between the transmission control valve and the transmission, preventing pressure from reaching the required level. Inspect and replace the gasket.
(5) Malfunction of the transmission pressure gauge, failing to accurately reflect the pressure values of each gear. Inspect and replace the pressure gauge.
