Possible reasons why the automatic transmission slows down:
Electronic:
* Faulty gear selector position sensor
* Faulty speed sensor
* Failure in the electronic control unit (ECU) of the transmission
* Faulty shift solenoid
Mechanical:
*Low transmission fluid level
* Worn friction discs
* Faulty torque converter
* Damaged transmission pan
* Clogged transmission filter
* Failed pan gasket
Other:
* The load is too heavy
* Towing a trailer without proper cooling
* Engine problems resulting in insufficient power
What to do if the automatic transmission slows down:
1. Check the transmission fluid level. It should be within the range indicated on the dipstick.
2. Carry out diagnostics with a scanner. This will help identify any electronic fault codes.
3. Change the transmission fluid and filter. This can solve problems related to contamination or wear.
4. Contact a mechanic. If the problem persists after the above steps, contact a qualified mechanic for further diagnosis and repair.