P R N D 3 2 1 Indication Went Out

[Texasoilman44]

Just curious if anyone else has had this problem (hoping others have and GM will pick up the bill to fix)

Gear indicator quit working. Truck drove fine for about a week and then would not shift. Took to dealer, performed following:

600 REPLACED CABLE AND NEUTRAL SAFETYY SWITCH
88996496 CABLE KIT
29540479 SWITCH KIT

Total was $424.64 for parts and labor.

Regards,

Kevin

[More Power]

Do a search here in this drivetrain forum for the keyword NSBU. This is the Neutral Start BackUp switch. The switch is about $50-60 at an Allison dealer.

MP

[pgreen]

I just replaced my NSBU switch in my 2002 about 3 days before trading it in! :mad:

Less than $50 at a local Allison dealer, but something stupid like $250 at the STEALER. Same part, same part number, same box.

Took about 15-20 minutes to install in a parking lot.

Thanks to the DIESEL PAGE I knew what the problem was when my wife called me with the problem description. I showed up with a switch and all the tools to change it in the grocery store lot!

[medic198]

Same problem, 107,000 miles. Caught me out of town just outside of Ohio/Pa line on I 90. Total parts and labor. $160.55. I was in a real jam but was treated right. Don't have the repair order, something like 2- 700 code errors I think. Wouldn't shift, no D and or R if I remember right.

[madmatt]

you all got off easy. a cust. of mine needed an IPC (insturment panel cluster) @ about $800 parts alone. he's never quit shifting, just didn't know what gear he was in.

[madmatt]

spelling correction....his......sorry

[Zapper]

Unbelievable!!! This is exactly what just happened to me tonite. My indicator lights quit working yesterday, actually every other one would not work, and tonite when I am leaving work (believe it or not I work at the Allison PDC in Indy) my truck only had 3rd gear. So are you guys telling me all I "probably" need to do is replace the NSBU. I was going to take her to the dealer tomorrow but would rather not, maybe a tech that frequents this site can chime in.

[timssilverchevy2003]

Last night, My check engine light came on. At the same time I noticed I did not have indication of R or D. Truck still going, but driving lights and reverse lights don't work. Checked the code with a scanner- came up 0708. Looked it up and indicated a fault with NBSU switch. Going to do some research on part replacement. Anyone get this replaced under warranty?? 38,000mi

2003 CCSB D/A
Best truck I've ever owned!

[pgreen]

If you cannot get it replaced under warranty, look for an Allison Distributor in your area. The part will be significantly cheaper than the dealer. It is easy to change (3 bolts? and one connector). You will have to have the codes reset after you change it too.

If you can do it yourself, it will probably be less than $50 total, and about 1/2 hour.

Good luck if you want to deal with the Warranty!

Phil

[timssilverchevy2003]

Went to the dealer- they said they'd have to keep it over the weekend. I told them thanks but no thanks.

I'd rather replace it myself. Anyone know an Allison shop near San Bernardino, Ca?

[Modified]

Great instructions was on this site a year ago. More Power has it.
http://www.thedieselpage.com/back03.htm

A spare switch can be ordered here.
http://www.gmdieseltech.com/store2/cart.php?target=product&action=view&product_id=16197&category_id=278

[pgreen]

Try this:

Allison Sales and Service Locator for San Bernardino CA (http://www.vicinity.com/allisontrans/geoprx.hm?cty=US&cont=1&AD4=US&DBR=100&FC=P&AD2=&CITY=san+bernardino&STATE=ca&ZIP=&x=65&y=9)

I would try #5 first, as they are an Allison Distributor. Pricing will probably be more in your favor. Some of them may even be open on Saturday.

Good luck!

P

[madmatt]

a code p0708 is pretty much a sure sign of a failed PNP switch (or nsbu if you perfer). sometimes it will be acompanied by a p0700 code. the p0700 is just a tcm mil illumination request and the p0708 is the PNP code. usually you will notice a harshness in shifting between gears and no illumination of D or R on the indicator. had one today actually that had both codes and the P, R, and D did not illuminate. replaced the PNP switch and refalshed the TCM but P still did not ill. Found the detent spring in the shifter ass. had broke and part of it was gone. I inserted a shim made of 6 6mm flat washers to correct the problem. if you think you have this problem, the shifter will be really sloppy in P.

[madmatt]

the P/N for the park neutral position switch is 29540479. my dealer sells them for $165.17 but this P/N is a good Allison #. The Indy Dealer has them in stock, I called there today. Over $100 cheaper there.

[Biodiesel6.6]

I'm not sure if the switch is bad or not?
I replaced the switch with a new one over a year ago this past Oct. Yesterday went to plow a driveway and hooking up the plow. Put truck in R and didn't want to move, back in park and noticed SES on. Back to R and ok, drove down street and wouldn't shift right. Indicator lights looked ok, but thinking about the problem. When plowing the firmness into R was harder than normal. I finished the driveway, turned off truck, got paid and off I went. Drove about a mile and every thing was ok. Went home checked fluids, ok. I was thinking it might have been a stuck selinoid because the trans temp warmed up fast 150 by the gauge. It was about 32 out, in a 50 garage, front winter cover on and in use less than 30 min. I had one stick last year while plowing and toasted the converter. GM rebuilt the training under warranty last year in March at 24k. 39K now.last time the selinoid gave very hard P to R shifts and set codes. Restarted truck and shifting was fine. The SES stayed on for about 10 starts. Yesterday after about 5 starts the SES was off.

New switch or something else?
Terry

[Biodiesel6.6]

Read the 2 codes P0700 TCM
P0847 Trans Fluid Pressure Sensor/Switch B Circuit Low.

NSBU related?

Terry

[madmatt]

according to the code alone it doesn't look like a nsbu/pnp switch. but the TSB on the nsbu switch does advise if you don't already have them, installing a set of front mud flaps will reduce the chance the a reoccuring nsbu switch failure. Also when changing a nsbu switch I pack a ton of di-electric grease under the dust cover that goes around the gear selecter shaft and in the connectors.

[MA]

Originally posted by Biodiesel6.6:
I'm not sure if the switch is bad or not?
I replaced the switch with a new one over a year ago this past Oct. Yesterday went to plow a driveway and hooking up the plow. Put truck in R and didn't want to move, back in park and noticed SES on. Back to R and ok, drove down street and wouldn't shift right. Indicator lights looked ok, but thinking about the problem. When plowing the firmness into R was harder than normal. I finished the driveway, turned off truck, got paid and off I went. Drove about a mile and every thing was ok. Went home checked fluids, ok. I was thinking it might have been a stuck selinoid because the trans temp warmed up fast 150 by the gauge. It was about 32 out, in a 50 garage, front winter cover on and in use less than 30 min. I had one stick last year while plowing and toasted the converter. GM rebuilt the training under warranty last year in March at 24k. 39K now.last time the selinoid gave very hard P to R shifts and set codes. Restarted truck and shifting was fine. The SES stayed on for about 10 starts. Yesterday after about 5 starts the SES was off.

New switch or something else?
Terry My 01 has been doing the same. Originally replaced the NSBU in Jan 03. Then mid Nov I had this problem. Dealer swapped out the NSBU again. They said it was install improperly ( :confused: after almost 2 years?). Anyway, 2 weeks later same thing. Swapped it again. 3 days later same problem.

Took it to another dealer. He just called and said the TC is draining back and there is a TSB on this. Since mine is out of warranty and to install the module that will supposedly fix this they have to pull the trans the damage is $1300.

I've read that you can get around this by starting the truck and not shifting. Let it run and then shut it off. Then restart.

Nice but not an option for me since my GF tows her horse with this truck. Last thing I need is a call from two states away that she's stranded and Sam is kicking the trailer ramp down. :eek:

[timssilverchevy2003]

Well, I went to the dealer and had them check the code (P0708). They told me they reset the code and went on a 5 mi test drive- found no errors. The next day, I noticed the PRDN321 indication was out again. Tranny was in 3rd, and when I came to a stop I placed the tranny in P and "Shift inhibit" indication came up. I shut down the engine, and restarted. All clear- except for gear indication. I limped it home- checked connections and restarted the engine. All appeared to be working. Intermittently, though the indicator will go out.

I'm going back to the dealer- I saw there was a TSB out for this in another post. We shall see...

[truck31]

I just had a GM dealer put a nuetral safety switch in my 2001 3500 Duramax. I was out in the woods and it took me about an hour to drive in third gear to reach him. I was glad to get it done. I had to twist his arm. I doubt if Chevy is going to honor anything. He all so told me my truck idle was fluctuating and that I will need new injectors. Something to look forward to. I need to make arrangements with Chevy dealer for sure.What a pain in the Ass.

[madmatt]

did he do any diag to see if it was the injectors? FPRs often cause this idle surge. it's most noticable @ a stop, in gear holding the truck w/your brakes.

[SatchMax]

My lights were acting up and thought my was going out. Son had same trouble with his 01 excab long bed and change it himself. Mine is still work fine but carry a new one waithing for it to go out. Main thing is to put shifter in neutral to change this switch. We both bought or switch through a chevy mechanic for about $100. Waiting for my to go out.

02/3500/cc dually--70000 miles with 8 new injectors.

SatchMax
Lubbock, Texas

[truck31]

All he said is it surges at idle and he got a code for fuel primer.Plus he wrote something else down that I can't read. This was a GMC dealer that told me I needed the injectors changed. He said that he has done several and they changed all eight. The Chevy dealer I went to today was willing to check the truck code but I would have to leave the truck for the day. He also told me that If it needs an injector , that they will change only the bad one . He went on to say that I should try an injector cleaner first to see if that takes care of the surging. He said that if they find that the injectors are clogged from dirt that Chevy will not Warrant them. I know this guy doesn't want to get involved because the first thing he asked me is if I bought the truck from him. Some dealers are great but a good many suck. They are not making any money you see. I am out in the woods and it is hard for me to get back to the dealer where I bought the truck. Two hour drive.

[madmatt]

find another dealer cause that on edoesn't know what he's talking about. If one injector is bad all eight should be replaced, and for the clogged injector, i think he he getting confused w/ a recently released bulletin for gas engines that are found to have dirt in the injector inlet screens.

[xwing]

I changed the switch just now in my driveway, took about half hour. Easy to do, no instructions needed; the "hardest" part was finagling the 2 connectors off, they are on there tight.
Cost $32.88 + tax at Advance Auto Parts; they called it "Item Number 19970175, Switch Neutral Safety NS85"; it has a 1 year warranty too.

My dash indicator started not showing Drive sometimes, then sometimes it would only go into Park, Neutral, Reverse, and 3rd gear and do no forward gear shifting (so top speed about 50mph at redline).

I heavily greased the area that goes on the shaft and the entire gasketed circumference of the unit with Mobil 1 Grease so as to try to avoid water getting in anywhere again. Put a film of grease on connectors too, for easier removal next time smile.gif Probably will think about hodging up some sort of shield for it when it's warmer outside.

[movemyrv]

MADMATT------ What's an FPR? My o4 LLY hs a slight stuble or pulsing at a stop or very light throttle. almost don't notice it but it's only 30 days off the lot (new) and has only 1900mi. Any ideas are appreciated, haven't tested the helpfulness of the dealer yet.

Mike
04 LLY crew 2500 HD