Brand New 47RE... Still Issues

[JOHNFAK]

I'm not getting a temp light, but it seems as though the truck may actually be starting in 2nd gear since takeoff is slow and I can get up to 40 mph around 2000 rpm.  I'm not sure if this could be limp mode, since limp mode starts in 3rd gear, or so I hear.  Our issues seem similar.

Everything I'm hearing is pointing to pressure, which makes sense.  I'm just terrible at diagnosing what is causing it lol.

 

Could be limp mode ....... you need a scanner on it to pull codes.

 

My brand new tranny put me in limp mode too  

Beyond that you need to check line pressure at idle (hydraulic hose and guage) and as you manually switch between gears.

 

But like W&F said - you really need to get on the phone and talk with builder and get an action plan.

[gradymayhem]

Alright, I've got a few things to investigate.  Thanks a lot guys, helped me sort through the issues.

[diesel4life]

Like was mentioned already locate a scan tool and see if any codes come up. If you have the EXACT same symptoms before and after I'd suspect the PCM or possibly a wiring/ground issue. When the PCM went bad on my truck it would not shift properly at all and also started in 2nd gear every time.

[Ilikeoldfords]

Being as the issues are almost identical with the new transmission as they were with the old, I would almost say you can rule it out. I would definitely be looking at the PCM, and wiring in the truck. Just a quick question, what does your AC voltage look like coming out of the alternator? If it is high enough it could be messing with the computers and such. Just something else to look at.