98 Caravan Limp mode

My 98 caravan with 3.3l engine intermittantly goes into limp mode (
more limp than normal ). When I limp, the PRND2L indicator on the dash
is all boxed with no spedo. I looked at the DTR codes and got a P0500
Spd Sensr A failure......not knowing which sensor input or out from
the tranny I changed both of them. It did not help. Is there some
other speed sensor I missed?

Several months ago the fuse to the TCM blew ( F11) ....I replaced it
and went on. The fuse & TCM plug look good now.

I took the van to a part time mechanic and he was not able to look at
the codes and suspects some communication problem.

Any advise here? Is my TCM FUBARed! Can I just swap the TCM out from
one found in the bone yard? ( somebody warned me about calibration )
Any help / advise here would be appreiciated.

Thanks in Advance
Steve

 

Have a competent tech go through it. You're going to waste more time and
money guessing and shotgunning.
Larry

 

Agreed, have a real tranny mechanic check it through-out using his
experience, knowlege and SnapOn Scanner. Some of those Techs are fine,
decent people who will help you at a fair price.

LS

 

well since you got a p0500 you will need to access the trans controller,a
scan tool for the tran's not a code reader some part timer might have
i suspect there is some hard faults in the tcm and i would wager it's a
output speed sensor unless the vans been wrecked then i would look into
the fuse blowing issue more and the engine harness
never the less to make sure you don't spend the wrong money take it to a
full timer trans shop at least