2000 caravan transmission

The transmission on our 2000 caravan seems to be shifting in and out of overdrive when cruising. If there is a hill or it is pulling it does not shift up and down. The tach jumps about 500 rpm’s and I can feel it shift. Would one of the sensors be at fault. I have not checked the codes yet with a scanner.

Limpy:

Is it shifting in and out …or NOT shifting in an out? It appears to do both .

Are you saying it shifts in and out when it shouldn’t …and won’t when it should?

How is the fluid level? It should be checked hot (driven 10 miles) on level ground in park.How does the fluid look and smell. If you decide to change the fluid use only ATF+4, don’t let and oil change place talk you into using Dextron with an additive pack.

That could be a converter clutch issue. It needs to be scanned with a scanner that can access the TCM and monitor converter clutch operation.

transman

we went on a short trip this past weekend and I watched the tach very closely. I discovered that it only does the ‘shifty’ deal when in 'Cruise control". I can hold it very steady at any leagal speed and it does not vary rpm’s. When the cruise is engaged it will vary, there fore, I shall check all the codes and also all the connections that pertain to electronic engine control and transmission functions. This erractic behavior with rpm’s just started about 3000 miles ago and I have not taken the time to check the codes.

Could this just be a case of loose wiring. I will start with the speed sensor. Also have the codes read as you are.