Final answer:
To check auto transmission fluid levels, warm up the vehicle, use the dipstick to measure fluid level, and follow the vehicle's owner manual for specific instructions.
Step-by-step explanation:
The best method of checking the fluid level in an auto transmission generally involves a series of steps that may vary slightly depending on the specific vehicle. Usually, you will need to start the car and bring it to operating temperature, then locate the transmission dipstick under the hood. With the vehicle in park and the engine idling, pull out the dipstick, wipe it clean, insert it back into the tube all the way, and then withdraw it again to check the fluid level against the marked indicators on the dipstick.
It's important to consult the vehicle's owner manual for the specific procedure recommended by the manufacturer, as some newer models may have a sealed transmission without a dipstick, requiring a different approach for checking fluid levels. Keeping the auto transmission fluid at the correct level is vital for vehicle performance and longevity.