03 lb7 range shift inhibited

03dmaxkolb

Hooking & Cooking
Jan 12, 2012
24
0
0
Sumner, IL
so this started happening before i even built the tranny but has only got worse since. it come up range shift inhibited and will clunk as u go from reverse to drive. sumtimes ull have to shut it off and it will go into gear when u restart. put a new NSBU switch on rodded it around shut if off restart a few times and it was going into gear came back out 15 min later and here we go again! noticed the connectors were kinda gunky could need cleaned a bit? once u get it into gear it runs fine until u shut if off and try again. :mad:
 

DieselDummy

Dirt Dummy
Oct 13, 2011
238
0
16
NY
All i can say is check your grounds, mainly the ones on the body mount below your feet and the two that are connected to driver side of block. Don't ask me how i know, but ever since i cleaned mine, i haven't had an issue with mine and i fought it for a month.
 

03dmaxkolb

Hooking & Cooking
Jan 12, 2012
24
0
0
Sumner, IL
yep put it on in neutral tryed adjusting it from level to angle each side in the slots. plugged in good. put a new valve body on it the other day same issue. so tryed to reflash the TCM but it wouldnt accept so thats my next idea. after trying to reflash iv lost the indicator bar for range selection and now i got reverse with a hard clunk. before i had to mess with it to get drive and didnt have reverse hardly. it started getting bad and would only act up when it got to operating temp. so i assumed it was valve body trim valve shit but nope!!!!!!!!!! and no ****ing codes. but i dnt think the TCM is communicatiing! any thoughts!:mad::mad:
 

AubleAK

New member
Aug 5, 2011
781
0
0
30
Glennallen, AK
Mine clunked into gear and wouldnt show my gear when my NSBU went out. I have an ecm and tcm spare if you need to buy another of each. Id check all of your connections also. Make sure there clean.
 

03dmaxkolb

Hooking & Cooking
Jan 12, 2012
24
0
0
Sumner, IL
iv pulled the connections off TCM blew with air. checked the nsbu heated them up before plugged in. i bought the NSBU off merchant surely it aint bad.
 

AubleAK

New member
Aug 5, 2011
781
0
0
30
Glennallen, AK
You might try pulling all the connections of the trans, and use that electric clean spray. Maybe you have a bad harness. I dont know near as much as alotta guys on here, hopefully they will chime in.
 

Fastorange

New member
Jan 31, 2009
256
0
0
ohio
Ive seen something like this before.... it had something to do with the trans pan... i know it sounds crazy but we had a truck in the shop that acted like your did.. an the trans pan was hit slightly where you couldent tell... had something to do with pressure
 

03dmaxkolb

Hooking & Cooking
Jan 12, 2012
24
0
0
Sumner, IL
i havent messed with the grounds. and i mean the NSBU could be bad. however when we tryed reflashing the TCM it wouldnt take kept having errors. so i ordered one having danville reflash monday so we ll c. if the TCM dont fix might b the NSBU or else were down to harness or ECM. i will b an irrate mother F***** if i spent all this money and the new NSBU was bad lol
 

DieselDummy

Dirt Dummy
Oct 13, 2011
238
0
16
NY
Put your old one back on. Mine had no communication with TCM but was intermittent. Changed nsbu, tcm and didn't fix it, lotta frustration and swearing for a stupid ground issue!!! Hope you get it fixed!!
 

03dmaxkolb

Hooking & Cooking
Jan 12, 2012
24
0
0
Sumner, IL
lol well i cant exactly put the old one back on it pissed me off so i busted the plastic off so i could unplug it lol. the TCM will b here this week if it doesnt fix it. ill check the grounds.
 

rgullett83

Active member
Oct 27, 2008
1,607
0
36
Illinois
sorry I never got with you, been working a lot of overtime at work, i have no doubt that mark will get it lined out for you
 

chevyluv

New member
Apr 8, 2014
2
0
0
Sounds to simple, but check the cooler lines for leaks/radiator and external cooler make sure transmission is full with the RIGHT FLUID ! 1ST one I built came back with this issue found out it was leaking up front, it will start throwing that inhibited range light on the dash when it's low on fluid and or go into failsafe mode. Hopefully this helps someone.
 

PACougar

Active member
Jun 27, 2012
2,105
1
36
41
El Dorado Hills, Ca
Sounds to simple, but check the cooler lines for leaks/radiator and external cooler make sure transmission is full with the RIGHT FLUID ! 1ST one I built came back with this issue found out it was leaking up front, it will start throwing that inhibited range light on the dash when it's low on fluid and or go into failsafe mode. Hopefully this helps someone.

Did you read the thread before you posted? He fixed the issue with a new TCM. You're only 2 years too late.