When my tranny failed, there was no check engine lights that came on. The only way that I knew that something was wrong was the rumble noise and weird shifting/almost slipping at cruising speed at low rpm's.
It's all behind me now, fortunately it only cost me $1200, the dealer absorbed the rest of the cost for the tranny and the rad. I was told that Nissan thinks that the manufacturer of the radiator thinks that there was a huge batch of bad radiators that was produced early on and ended up being installed in the early Pathfinders and Frontiers. Apparently the new rads are supposed to have been re-designed or upgraded or something like that.
I'm still gonna phone Nissan Canada and give them an earfull. Worst case scenario, they'll tell me to pound sand, and best case, they'll give me my $1200 back or give me more warranty or something.
Crossing my fingers,