Possible reasons why the automatic transmission stalls when starting off:
1. Problems with transmission fluid (ATF) pressure:
*Low transmission fluid level
* Leaks in the hydraulic system
* Clogged transmission filter
2. Solenoid malfunctions:
* Faulty solenoids that control ATF flow
* Solenoid contamination
3. Problems with the torque converter:
* Worn or damaged torque converter
* Torque converter lockup slip
4. ATF pressure too high:
* Transmission radiator clogged
* Clogged oil filter
5. Malfunctions of electronics and sensors:
* Malfunctions of the electronic control unit (ECU) of the transmission
*Speed sensor malfunctions
* Troubleshooting throttle position sensor
6. Mechanical faults:
* Worn or broken mechanical components inside the transmission
7. Engine problems:
*Low engine oil pressure
* Ignition system malfunctions
* Fuel supply problems
Diagnostics and troubleshooting:
* Check the level and condition of the transmission fluid.
* Check for leaks in the hydraulic system.
* Replace the transmission filter and transmission fluid.
* Diagnose solenoids and replace them if necessary.
* Inspect the torque converter for wear or damage.
* Check ATF pressure and replace transmission cooler or oil filter if necessary.
* Troubleshoot electronics and sensors.
* Check the engine for mechanical problems.