Hey Guys, I had a battery with a bad cell and while I was turning my ignition on and off very fast my AT CHECK light has come on, but no Check Engine light and no codes when I read it with my OBD reader. Tranmission is now in fail safe mode and won't shift so I took it to a transmission place and after $800 and finding no causal factor of the problem, told me I need a new valve body and TCM and possible trans rebuild. They did the following tests;
Data showed gear changes in road test but gears didn't shift.
Checked Trans fuses, all good
Removed front cowl and checked Trans fuses, all good
Disconnected Trans Connector, Checked B+ and B- as per schematic, all good
Checked KOEO power to connector, all good
Checked voltage on Can High and Can Low Bus Lines at DLC, all good

I don't really want to spend $6K on a 15 year old car. Any thoughts on what it could be or what I could have pooched while cranking the ignition on/off? Any help is truly appreciated!

 

Tow to Nissan for their diagnostic.

 

Were you able to resolve your A/T issue.
Im having the same issue.
started up pretty quickly and I’m in fail safe mode..

 

Yes, in the end I believe it was the TCM board that went and it was about $4500 Canadian to have fixed. Works fine now.....Good luck!