Possible reasons:
1. Transmission fluid problems:
* Insufficient fluid level
* Contaminated liquid
* Using the wrong type of fluid
2. Mechanical problems:
* Worn or damaged clutches
* Faulty shift solenoid
* Problems with valve body
3. Electrical problems:
* Faulty sensors
* Damaged wiring
4. Software problems:
*Transmission control module (TCM) software errors
Diagnosis and troubleshooting:
* Checking the level and quality of the fluid. Check the level and condition of the transmission fluid. If the level is low or the fluid is dark or smells burnt, it needs to be replaced.
* Scan fault codes. Connect a code scanner to the vehicle’s diagnostic port and read any transmission-related trouble codes. This may help determine the specific cause of the problem.
* Inspection of mechanical components. Inspect the clutches, solenoids and valve body for wear or damage.
* Checking electrical components. Check sensors and wiring for faults or damage.
* Update your software. If the problem is software related, you may need to have it updated by your dealer.
Preventing the problem:
* Check the level and condition of the transmission fluid regularly.
* Change transmission fluid according to manufacturer’s recommendations.
* Avoid aggressive driving and sudden acceleration.
* Carry out regular vehicle maintenance according to the manufacturer’s schedule.