[dirtyd]

I just recently rolled over 59025 miles on my Titan and got more strange problems. The "SERVICE ENGINE SOON" light came on, along with the "AT CHECK" light which flashed shortly then went off. I have been driving extremeley careful since the rear end went out, and I have no idea what to do. The engine makes a faint whining noise when reved, but I don't know of anything with the transmission.

 

[Carbeaux]

Hmm, have you tried to get the codes? If you can, it would narrow it down.

 

[baseballfanz]

Yeah if you can get the code pull it would help. You can go to Autozone or similar place and they can pull the code for you.
You could also try to read the code yourself, check in the how to section.
There is a TSB for ATP switch but with the code you will know for sure.

 

[Arachnid]

These guys are right, pretty tough to diagnose the problem without computer assistance. You can also purchase a code reader fairly inexpensively so you don't have to rely on the shops.

 

[dirtyd]

I finally found out that the problem is a transmission fluid diverter valve or something, is this serious?

 

[baseballfanz]

I finally found out that the problem is a transmission fluid diverter valve or something, is this serious?

I would think anything to do with the tranny is serious. Did you ever get the code?