I have a 2002 Elantra Auto...
I had a problem a year ago where i'd be driving at highway speed and the transmission would drop to 3rd (fail safe) and would only return back normal if i pulled over and switched off.. This turned out to be the pulse generator.
A new problem is now effecting me... From switching on i drive from 1st to
2nd then high revs before jumping to 3rd.. Then i remain in 3rd when speeding up or slowing down.I switch off.. back on and it drives like normal.. I switch off back on and the same error occurs. I've not determined if this is from a cold start only but it's at the shop now so we'll see.
Any ideas what the problem could be?