The RE4F03/4B transmission in several Nissan vehicles develops a hard 1-2 upshift as a result of uncontrolled line pressure. Sometimes code P0745 is stored for a problem in the line-pressure-control solenoid circuit. Replacing the solenoid assembly usually fixes the problem. But, the next time this happens to you, or you get to experience this for the first time, the fix may be as simple as gently squeezing a crimp.
The RE4F04B transmission is no stranger to our technical hotline, for a variety of reasons. This article is about a self-inflicted injury that occurs every so often and, when it does, makes for a very bad day.