Range shift inhibited

[leod902]

What does this mean? I am not able to get any higher than 3rd gear and now the check engine light is on. I've had no problems with the truck ever and this one has me baffled. The indicator light on the dash will not light up except in 1, 2, or 3. Also, I am seeing alot of talk about the programmers available. Anyone have any pros or cons on this? I want to start beefin this truck up, but keep it as reliable as possible.

Can anyone help?

 

[MMLMM]

Do you know what codes it threw?

 

[leod902]

I have no way of knowing. I just don't have the equipment . Sounds like I should invest in some.
Any chance it's a simple fix? Maybe a sending unit gone bad or a loose connection? Looked underneath, checked fluid levels, everything looked great.

 

[Righteyeblind]

Its the NSBU (neutral safety back up) switch. You can get one at Napa or the dealer. Cycle the key off and on I think 4 or so times and you can get it out of limp mode so it will shift past 3rd gear

 

[mainer]

go to your allison dealer not gm/ chevy dealer.... like $57 at ally dealer and like $250 at gm/ chevy

 

[d-max joe]

i have the same problem i think its the IMS box on my 04' cause i took tranny out today and put it back in and it wont even move and it grinds into park?? ever hear that