02 Dodge Ram 1500 Transmission Trouble

I have a 2002 Dodge Ram 1500 and think I am experiencing trouble with the transmission. I was on a trip recently and while I was driving I noticed my RPM was changing from 2000 to 2500 constantly back and forth. I think it may be slipping in overdrive. The engine service light is on too. Could this possibly be an easy fix?

One other problem I am having, is that the engine seems to be idiling up and down constantly, problem with the choke?

There is no choke and get it scanned for codes since the light is on.There are two soleniods that are a very common problem.Use the recomended Mopar fluid only and some parts stores sell it,Carquest is one that sells it under their brand name for about $4.00 a quart.

Transmission issues could be converter locking and unlocking. See if you can disable it by pulling a wire or fuse and see if it changes.

It is probally electrical and could be the soleniods in the valve body area.

get it scanned and see what codes come up if the motor is surging the it will surge going down the road too. could be the iac or tps causing the surge.get the codes to see what your shooting at.that way you ain't wasting bullets [$$$] shooting in the dark