Possible reasons:
1. Low automatic transmission fluid level: Check the level and condition of the automatic transmission fluid. Low levels or contaminated fluid can cause shifting problems.
2. Throttle Position Sensor (TPS) Problems: The TPS is responsible for detecting the throttle position and adjusting the fuel flow. A faulty TPS can cause shifting problems and a stalled engine.
3. Speed sensor malfunction. The speed sensor provides information about the vehicle’s speed to the engine controller. If the sensor is faulty, it can cause gear shifting problems.
4. Problems with the transmission control unit (TCU): The TCU controls the operation of the automatic transmission. A faulty TCU can cause gear shifting problems and a stalling engine.
5. Worn Clutch: If the clutch is worn, it can cause slipping when shifting and stalling the engine.
6. Clogged Fuel Filter: A clogged fuel filter can restrict fuel flow and cause fuel atomization problems. This may cause the engine to stall when idling or changing gears.
7. Catalytic converter problems: A clogged catalytic converter can cause back pressure in the exhaust system. This can lead to problems shifting gears and a stalling engine.
8. Other Mechanical Problems: Other mechanical problems, such as problems with the oil pump, oil pressure, or worn bearings, can also cause the engine to stall when the automatic transmission is in gear.
Diagnostics:
To diagnose the exact cause, the following steps must be followed:
* Checking the level and condition of the automatic transmission fluid
* Check TPS and speed sensor for faults
* TCU diagnostics using OBD-II scanner
* Inspect the clutch for wear
* Replacement of the fuel filter
*Checking the catalytic converter for blockage
* Check other mechanical systems for faults