i have an 02 auto,, that when i get around 1200 rpm, 40-50 mph, the tranny seems to want to shift back and forth,, creating a surging, like it doesn't know what gear it wants to get into,,,, what can be causing this,, i'm not much of a mechanic
thanks
cowboy

 

It's shifting in and out of overdrive.

Cheap and easy to fix cause of this is electrical noise.

Clean up the battery terminals really good, check all ground connections and make sure they are clean and have good contact,
especially the ground for the PCM, which is located behind the air filter on the passenger side firewall.

If none of that works, then you have to start with the not so easy and cheap fixes.


phox

 

Do a search. There are many threads about what phox is talking about. The grounds from the batteries to the fenders are the best bet. Also, add a ground from the PCM (firewall behind the airbox) to the battery.

If that doesn't work, you need to get a noise filter from DTT.