i have a 2001 2500hd with the 8.1l. truck drove fine all day. shut it down for 20 minutes, restarted and ses light came on and shift selector wasn't working on dash. doesn't go into gear immediately and when it finally does it bangs into gear. i went to move the truck and it feels like it's slipping. i used a scanner to read the codes and i got the following
po 700
p1 711
p1 713
po 7oopd
po 713pd
does anyone know what these codes mean? it's snowing up here and need to know if i can drive the truck, it's about 2 miles from home and it can't stay where it's at. any help would be greatly appreciated. tia

I bet it's the NSBU switch. Very common problem. Check to see if you have a black switch or the tan one on there.

Yes you can drive it. The tranny is stuck in 3rd gear and will rev to about 2000RPM but you'll get there.

You can also cycle the ignition a few times and see if it'll clear the code for now. It'll still be there in the history though.

i haven't checked the color the nsbu switch, but would it set that many codes when it craps out? do all those codes correspond to the nsbu? i will assume it's a dealer item only. the truck is still under warranty, so it will have to go there on monday morning.

duramax diesel, thanks for the help

Oh yeah, I had almost 10 codes when mine went out. I'm on my third switch. It's very easy to install. Are you still on your 3 year/36000 mile warranty? If so let the dealer take care of it. If not, don't buy the switch from the stealer, you can get it at an Allison dealership far less expensive. Nick

Mine acted up out doing a little four wheeling in the snow. The trans wouldn't go into neutral and I was stuck in 4 low. What a mess. After about ten minutes and a dozen shifts back and fourth it finally found neutral. Got it back to 2 high. I stopped at my dealer and picked up a new switch. After sitting in my warm garage all night the old switch worked fine but I decided to go with the new design. I dried the old one and put it in the truck for a spare. Later! Frank

FYI,
My duramax has 51,000 and I just had my NSBU replaced this week. I figured since I was beyond the 3 yr/ 36000 mile warranty I would have to pay out of pocket.

I took it to a large Chev dealer and he charged me nearly $300 to change it. Irritated with the price, I called a different chev dealer 30 miles away to see if they could have done better and their service dept mgr said it was covered under the emissions policy (who knows why it would be under emissions) and therefore covered until 100,000 miles. When I called back the dealer that replaced it he denied it at first, then went to look it up and sure enough, - IT IS COVERED. He said he certifies every year with GM and would have missed that test question and would have never guessed it be covered under the emissions policy.

So they credited back my card and submitted it to GM. They have changed alot of them for several years now and charged everyone whose 3/36000 warranty was expired, so they are going to have to go back and try to reimburse plenty of people.

My guess, is that many if not most dealerships overlook this as a warranteed item. If you paid for it and were under 100,000 miles I would be going back to the dealership for money back.