Yesterday, My overdrive stopped working out of the clear! When I connected my manual shifter, all 4 gears work. When I pulled the manual shifter out of the circuit, again I lost 4th gear. Does anybody have any insight on this problem? It has to be either electrical or the shift linkage isn't right. I need some quick info to narrow down my search, otherwise I'll have to go to the Infiniti dealership and pay them for 2-3 hours of computer time.

 

Well your car is so modded, I'm not sure they would know what to do with it. Sounds like the gear works but whatever electrical signal that tells the tranny to go into overdrive is not working. Do you have a shop manual?