Many things can go wrong when operating and maintaining a vehicle. From flat tires and leaking radiators to cracked windshields and damaged seats, there's almost always something to worry about. That means that whenever a car gets brought in for service there is likely to be something that needs to be done to it.
That is the way that so many shops are able to offer inexpensive free inspections. They know that they will likely uncover something that warrants a more extensive procedure. Knowing when to go in and when to possibly hold off is possible if you know what signs to look for that may demand transmissions repair.
One of the first things to look for and worry about is leaks. There are more than a dozen joints and gaskets around the gearbox, and any of them can have a defect that causes oil to spread. If it is leaking it needs to be fixed quickly because the less there is in the system, the less protection from damage and overheating it is going to receive.
Hesitancy to engage when in gear is a sign that transmission repair may be on the horizon. This could indicate any number of things, but most likely means something must be done to fix the problem before it gets worse or the car stops going at all. The old check engine light may refer to the auto's need for transmission repair.
With the computerization of all of the systems, it could mean any one of the systems has an issue. Whether it is the gears or not, it is imperative that it get checked out to determine what is wrong. It is not called a suggestion light. It is a warning, and a clear one that something needs to be checked out and soon.