Possible reasons:
*Low Transmission Fluid Level: Check the transmission fluid level with the transmission dipstick and add fluid if necessary.
* Contaminated or old transmission fluid: Transmission fluid can become contaminated or lose its properties over time, which can lead to transmission problems. Regular transmission maintenance, including fluid changes, is recommended.
* Faulty valve body: The valve body controls the flow of fluid in the transmission. A faulty valve body can cause problems shifting gears or a stalling engine when you engage a gear.
* Worn clutches: Clutches transmit torque from the engine to the transmission. Worn clutches can cause the engine to slip and stall when shifting into gear.
* Faulty Speed Sensor: The speed sensor tells the transmission how fast the wheels are spinning. A faulty sensor may provide incorrect information, which can lead to problems with shifting.
* Electronics problems: The automatic transmission is controlled by an electronic control unit (ECU), which can fail or have faulty wiring.
* Other mechanical problems: Wear on internal transmission components, such as gears, shafts, or bearings, can also cause the engine to stall when shifting into gear.
Recommended actions:
* Check the transmission fluid level.
*If the fluid level is low or the fluid appears dirty, consult a mechanic about transmission service.
* Carry out automatic transmission diagnostics with an OBD-II scanner to identify any fault codes.
* Contact a car service for further diagnostics and repairs.