01-04.5 LB7 Duramax PowertrainDiscussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission Ect
Warning: The following is going to be long winded...
I started getting this message (Range Shift Inhibited) on Friday when trying to shift the Allison into drive to head home. The truck would only go reverse and 3. Well, I can't begin to explain how frustrating it is to go 36 miles on a highway home doing 40 MPH so you don't overheat or redline and blow everything to pieces before you get home. When I got home, I hit the net looking for solutions and found two that are linked to this somewhat fairly common problem.
The first and most common is the NSBU switch located on the dirvers side of the trans. Apparently dirt or moisture can get around the seal on the connectors and cause this problem. Easy first step is to disconnect, wipe clean, blow out and reconnect. I head back on the road and everything is fine for 15 minutes, then BAM... loud clunk, message back and stuck in 3. And a damn good thing I didn't bust something loose since I was doing 50+.... So, I sit back, let a few expletives fly and think about some things that may have led up to this to decide which direction to go from here... Replace the NSBU switch or look into the ignition switch?
While limping it back home I remember in the last month I have noticed that at times when kicking the turn signals on, both might flash or one stay on solid. I ran out of gas a week ago because the orange light never came on and the needle was a shade under the 1/4 tank mark. During the day Friday when I was driving, I would park at my destinations and when I would put the truck in park, the doors didn't unlock. Now, I'm really starting to lean towards the ignition switch located in the column, since I think that these other things may be linked...???
This is where I am in my conundrum. I'm asking for help from anyone who might have a clue on this as with my recent injector issues (again), this things beginning to bleed me. And if I can avoid spending the $250 on the NSBU plus whatever the cost is for the ignition switch... I will be happy if I can just shell out the $ for the right fix the first time instead.
Thanks in advance people...
__________________ 2004 GMC 3500 Sierra 4 Door Dually LB7 Duramax (Stock)
Like I said... Double checked all grounds. Cleaned the NSBU real well, and the issue returned. Did you read my other issues, and if so what do you think of the possibility of the link to the ignition switch? I know the NSBU is the most common, but I can't ignore my other recent issues as possibly being tied together...
__________________ 2004 GMC 3500 Sierra 4 Door Dually LB7 Duramax (Stock)
Last edited by CrockerNut : 11-02-2009 at 10:59 AM.
So I went with the gut feeling (And pocketbook) and replaced the ignition switch on Wednesday. Not the problem at all - No change. Yesterday I ordered the NSBU online since it was $200 cheaper than from the thiefs errr, dealer. It should arrive tomorrow, and with any luck my tranny issues should end.
__________________ 2004 GMC 3500 Sierra 4 Door Dually LB7 Duramax (Stock)
I was going to say, the NSBU switch shouldn't be all that expensive- under $100 IIRC...
__________________ '05 CC/SB, AMSOIL 5w-40, KN Cold Air Intake, PPE Tuner level 1, EGR blocked, MP mod, res. plugged, lost KITTY, finished off the rest with 4" SS Magnaflow
Alright... Last Thursday I replaced the NSBU in about 45 minutes (Anyone doing so that needs tips, don't be afraid to ask). Turned the key on, cleared the codes, started the truck up and everything was back to normal. All of that frustration over a $100 part...lol. I do however have to take out the ignition switch I put in and drop the old one back in place because the new one leaves the battery light on if you're not careful when pulling the keys out... Saturday I didn't catch it and had dead batteries Sunday morning.
Anyway, I have a question about introducing a chip. I have heard that certain chips are known to create the NSBU problem again. Someone told me to avoid PPE, Edge and Bully Dog to be sure... I'm curious if there really is a correlation between adding a chip and frying the NSBU again. Has anyone heard of such a thing, and if so is it specific to the ones I named and maybe one or two more? Or is there an inherent risk when introducing anything new?
__________________ 2004 GMC 3500 Sierra 4 Door Dually LB7 Duramax (Stock)
Been running my PPE for bout 2 years and have only had one issue with mine, and I believe it was a moisture/condensation problem. Didn't change switch and no issues since. I have also never heard that this was an issue???
__________________ '05 CC/SB, AMSOIL 5w-40, KN Cold Air Intake, PPE Tuner level 1, EGR blocked, MP mod, res. plugged, lost KITTY, finished off the rest with 4" SS Magnaflow
I've never heard of a chip causing NSBU switch problems.
There is a big reason why Allison put the NSBU in the inside of the tranny beginning in 2006.
__________________ 2007 LBZ Daily driver, single stock cp3, stock engine 11.70 @ 115mph on #2, 677 HP
23.5 MPG Diesel Power Challenge 2008
2002 LB7 Fun truck 9.801 @ 139+MPH on #2 fuel only
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. So, I sit back, let a few expletives fly and think about some things that may have led up to this to decide which direction to go from here... Replace the NSBU switch or look into the ignition switch?
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