Skip the auto shop - Our mechanics make house calls

Q: Transmission shifts up and down randomly.

asked by on

The truck shifts in and out of overdrive to a lower gear randomly

My car has 105,000 miles.
My car has an automatic transmission.

This may be a result of a faulty transmission control module. A faulty transmission control module may cause a delay in acceleration or erratic shifting of gears. The transmission control module has various sensors such as vehicle speed sensors, wheel speed sensors, throttle position sensors, turbine speed sensor, and transmission fluid temperature sensors that all direct information to it in order for it to perform it’s function. A kick down switch is also operated by the TCM which controls when the transmission downshifts. When this is faulty, this may cause the erratic downshifting out of overdrive you describe. Any of these may also affect the way the transmission control module performs and controls the transmission and the shifting of your vehicle. I would suggest having a professional from Your Mechanic come to your location to properly diagnose your transmission shifting problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: hard to back up when van gets hot okay when it's cold

Hello, thank you for writing in. The vehicle is likely having issues with the transmission fluid. If you have not had the transmission serviced, it is time to check the level and condition of the fluid and replace the filter....

Q: truck overheating

Hi there. The problem you're describing tends to occur when one of two issues exist. First, overheating while towing can occur when air bubbles are trapped in the coolant lines. A second issue could be the coolant temperature sensor that...

Q: Code read

When the check engine light comes on and you test it and get a code then you will need to have the pinpoint test done for that code until the problem is found or the problem cannot be verified again....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...