How to Diagnose Automatic Transmission Problems

Transmission Fluid May Need to be changed
The most common symptom is when you start your car in the morning, especially if it’s cold, you put it into gear and it hesitates before it’ll engage. That’s a sign that maybe you have a dirty filter, maybe it needs a transmission fluid change, for something like this you should go to an authorized transmission service center. If you want to check your fluid to see if it’s dirty, find your dipstick and on your dipstick it should tell you right on the side here, check while idling in Park or Neutral.
Transmission Fluid Should Be a Red Color
So you want to start the car, make sure it’s warm and check the fluid. With the engine running, pull it out and read it on the stick. There’ll be little cross-hairs where it should be in the middle of. If it’s over full it’s no good. This transmission fluid is a little brown, it’s dirty. Transmission fluid should be pink or reddish in color. It also shouldn’t smell burnt. A burnt smell is a sign of a problem internally with your transmission.
The Check Engine Light May Signal a Transmission Problem
Most new cars have a lot of sensors in their transmissions. All these sensors are hooked up to the car’s computer. So if there’s a problem, it probably set off the check engine light. If you have a shifting problem or feel something funny in the transmission and the check engine light comes on take your car to a qualified service center to have it checked out. You could have a problem with your actual transmission or just one of the speed sensors. So it could be a small repair or large repair, but it’s better safe than sorry.
Whether working on cars is a hobby or a cost-driven necessity, most DIYers and backyard mechanics are better off with inexpensive alternatives to expensive professional tools. There are some good tools that can interface with your computer, phone, or tablet.