P0875 on 2003 lb7

sack336

New member
Feb 8, 2016
6
0
0
annapolis, md
Hey guys,

So I recently replaced my NSBU a month ago cause snow kicked up into it. replaced it, no issues what so ever. been driving the truck every few days, went to get in it Thursday and it threw a code, drive still engaged and moved the truck as well as reverse. my question is do you think this NSBU could have gone bad this fast? code never threw until after i parked the truck then drove it a few days later. i replaced it with an Allison nsbu from merchant auto. I checked all connections on the nsbu harness and couldn't find anything there. any thoughts on this or common ways to fix this?


p0875 = transmission pressure switch reverse circuit

built trans from big dipper as well, george said to check out the nsbu but possibly could be a valve