The Nissan Path

My 2005 Pathfinder auto transmission would not go in reverse after driving for 15 minutes. I shifted in reverse and it just sat there as if it was in neutral; however, when I reved up my engine for 15 seconds it would go in.

When the trans is cool, it worked normally. Any help would be greatly appreciated.

My suspicion would be a faulty reverse clutch solenoid, but, it's hard to find the solenoids other than to replace the whole valve body/TCM assembly. The best thing to do to be sure would be to follow the trouble diagnostic steps in the factory service manual for the symptom of "no reverse" in the automatic transmission section. There's no cross-contamination issue with the trans fluid, is there?

Thanks for your reply. As far as I know all other gears work fine. So I don't think there is cross contamination.

I replaced the transmission fluid right after this problem occurred and no signs of coolant fluid in the transmission. So cross contamination is not an issue here.

I found a source for the solenoid for 69.95 plus shipping

http://www.makcotransmissionparts.com/63425.html

I will give it a try and see if it will cure the problem. Thanks for helping.
Also, will try to bypass radiator to prevent cross contamination.