Chevy and GMC Duramax Diesel Forum banner

1 - 16 of 16 Posts

Registered
Joined
8 Posts
Discussion Starter #1
I bought a used truck a couple days ago, and it came with a DSP 5 switch, but no screen/controller for it, so I have no idea what tunes are on it. Position 1 seems to be stock (my dad has a 2008 LMM), and as far as 2-5 I'm not sure. Im guessing eco, 25+ 50+ 75+hp. 5 definitely has the most increase. Anyways, I was out driving with some friends yesterday evening and i turned the switch to get on it, and shortly after, the trans mad a weird noise, slipped, and then threw a check engine light. Truck would rev, but wouldn't increase speed. I coasted to a stop and shut it off, and turned it back on a couple times, but it kept doing the same thing. I waited about 10 minutes for a buddy to flat tow me, and i started the truck after about 10 minutes of waiting, and it started moving just fine. Check engine light was still on, but other than that, everything seemed normal. It drove home just fine. I babied it at first, because I was worried I would do more damage, but then I was back at 60mph no problem. I got back to my shop and scanned the code and it was P0777 for a fault in one of the solenoids. I cleared the code, and it didn't come back. Im assuming its fine now? Did the truck sense the trans slipping, and de activated the solenoid to not cause damage? I don't know much about these engines/transmissions. It also blew out my oil dipstick and some oil residue was left in the engine, level didn't change, so I'm guessing the high rev caused the crankcase pressure to blow it out? The previous owner installed a blowby tube that vents to the atmosphere, and it has a small amount of blowby, which is normal right? I read a couple other forums on this issue with both the code and the dipstick blowing out, but didn't get much help from that. Any advise on what I should do if anything would be appreciated.
 

LHN...We ARE the Joneses
Joined
26,254 Posts
Fill out your signature so we know what model you have and the mods on it.

One of the reasons I'm not a fan of messing with the Crankcase Venting,....no gains and it's really a minute amount of oil residue in stock config. Get the bypass wrong and......?
Might wanna give their 'mod' a look-see for potential blockage/routing probs.

The switch.
There is no way to know what those 5 settings do....it's not a universal thing where 1-5 are all HP increase points. And you have no idea who's tunes they are. 'uhNo
There could be stock, light tow, heavy tow, economy, lope, valet, plus all kinds of combos for HP that it could have....all mixed up, could be stored on any 1-5 settings.

Yes, the trans didn't like what you did. They don't like beating on it with more than stock HP. People will run the higher stuff, for increased MPG, knowing not to beat on it, lest they have an extra $6k layin' about for a built trans.

I'm assuming its fine now?
Nope....well sorta. Do it again and it'll limp easier the next time...again and again if you keep on, weaker and weaker.
It lets up on the limp after several key cycles...the code was still stored, it didn't heal itself.
Keep your foot out of it and it'll run on.

Might wanna look into flashing tunes that you know are what's what, but that's not a cheap solution....but far cheaper than a new trans and TC.
 

Registered
Joined
8 Posts
Discussion Starter #3
So how do I go about taking off that crankcase mod? Like I said, I don't know much about what it does, I just know what it is. This is a daily driver and wont be beat on very much. However, I do want to be able to launch it and put my foot to the floor at times. I am eventually planning on getting a stage 3 Allison put into it so when I want to be able to do those sorts of things, I wont have to worry about it. I read that those can handle up to 550 hp, and I cant see my truck having a tune that would put it over that range, especially on a stock engine. (or atleast what I think is a stock engine). My dad told me to take it to the dealer to do a trans fluid and filter change, since this happened, plus its a used vehicle, so I want to get all the fluids changed. Is this something you recommend doing, or is that just a waste of money? I dot have a diesel shop around here (Central Illinois) besides the dealer, and they don't like messing with trucks that have mods done to them. What does flashing tunes mean? Is that able to be done at a Chevy dealer with a tech 2, or do I need to go to a diesel shop that knows about tunes? Another thing to mention, the truck has a wire in the engine bay, and it runs to the downpipe, so I'm guessing its a egt sensor. I had looked online into just getting an edge monitor so I can see the balance rates on injectors and some other gauges, just for safety in knowing things, and the wire looks identical to the one the edge sells that connects to their monitors. So I'm guessing thats what the previous owner had in it. Im really not educated in the field of tuning, so I really just don't know. Im definitely going to keep the foot out of it, and leave it in mode 2 (it seems to be the economy mode, since I get best MPG there) and just drive it normally.
 

LHN...We ARE the Joneses
Joined
26,254 Posts
While it is a good idea to service all of the fluids on a used truck you know not the history of, to establish a baseline for future maintenance, changing the fluid isn鈥檛 going to fix damage to hard parts.

Spend some time on researching the forum (DIY section) and you鈥檒l see how easy it is to service the Allison yourself, at a fraction of the price the Dealer would charge.

And this goes for every fluid in the truck. There鈥檚 no fluid or filter maintenance that can鈥檛 be done easily by you鈥gain, for a fraction of the cost.

Crankcase venting; search the pics鈥.stock, you have a hose from each valve cover that Tees into a short hose that taps into the side of the turbo inlet duct (where the 6.6 top cover hooks to).

No telling what method was used to bypass, until you look at it. Some will finagle a hose tied into the Tee to vent (which could be kinked in a bend), others run two lines, one from each valve cover, doing away with the Tee in the middle. And then there's the 3rd, installing a catch can for any oil, returning the draw tube back to the turbo inlet duct, maintaining the stock crankcase pull on gases.

Flashing a control module; is using an interface (like a Tech-II, or EFI V2) to write over the tunes/files with new data. The Dealer can only load/flash a stock tune, and it鈥檚 usually $200 to pull out a Tech-II, for anything.

A few Franklin$ more gets you into an autocal and EFI tunes from a reputable tuner, designed specifically for your truck and your needs/plans/wants.

And it鈥檚 not just unknown tunes to match the Allison strengths to be concerned about. Without knowing the quality of the tunes, there could be abnormal wear on engine parts and such from crap tuning.

We see Users running across this all of the time with a used truck and a DSP switch. I wish people would start leaving a note taped in the glove box on what and who's tunes the bought/installed. Would sure save the next owner a lot of headaches and expense.

The correct spot to place an EGT probe on a Dmax for accurate info (useful in knowing when something鈥檚 gonna melt) is back in the pass side manifold, not the down-pipe.
 

Registered
Joined
8 Posts
Discussion Starter #5
Ok, I will do some research on changing the trans fluid myself, I already ordered a cat oil filter and adapter to install when I change the oil on it. The dealer did an oil change when they got it, so I figured I would wait a couple thousand miles before changing it. Im goin to be using Rotella T6 full synthetic 15w40. That should be the best for the engine in terms of oil quality and filter quality. Unless you have heard bad things about the cat filter swap... Im also planning on changing the fluid in the front end and rear end to Lucas 75-90. As far as flashing the tunes goes. I found a diesel shop about 30 minutes from me, and I will give them a call and see about getting my truck in there and having them flash 5 new tunes on the truck to my liking, as well as hooking me up with the monitor that I want, which is gonna be a stock, eco, 25 50 75hp increase, or 50 75 100, whichever they recommend with stock internals, since I don't plan on opening the truck up. Then once those tunes are installed, I'll just leave the switch in eco tune until I can get enough saved for a stage 3 trans, then I can have that extra power to play around with if I wanted to. Good to know on placement of the EGT probe. I'll check out where they installed it when I check out the crankcase venting, and see about putting it back where it belongs. My dad has a bone stock 08 LMM so I can just look at that too. As far as a reputable dealer, how would I know how good this shop is that I going to be checking out? Or should I try and find one near a big city, such as one a couple hours from me? And if one in a bigger city is the way to go, would i be able to get them to create the new tunes, erase the old ones, and install a monitor all in the same day, or would it take a couple days for them to write the tunes? Thanks so much for all your help by the way, this forum has helped me out a lot with trouble shooting my dads trucks, as well as seeing what other people recommend.
 

LHN...We ARE the Joneses
Joined
26,254 Posts
That's the thing with EFI, it's all Email tunes. You load on your end. No need to find a local shop, it's worldwide if you have the net.
 

Registered
Joined
8 Posts
Discussion Starter #7
So how would they make the tunes for my truck without having my truck there? is it just specific to my engine and the mods that are done to it? Also, what would i need in terms of a monitor to download the tunes onto? Like I said, I would like an edge monitor, but there are many different types on amazon. Also, how would I erase the old tunes to get the new ones put in? Do I have to take it to a dealer to have them do that and then install the new ones when I get my monitor?
 

LHN...We ARE the Joneses
Joined
26,254 Posts

Registered
Joined
8 Posts
Discussion Starter #9
After reading that thread, and watching various videos, but Im still not exactly understanding everything. Let me ask you this. What exactly would an edge cts2 give me in comparison to an autocal? Assuming they both are canned units, I know the cts2 has models that come with canned programs, and some seem to just be a monitor to show some more gauges. I apologize if I am speaking in extremely inaccurate terms
 

LHN...We ARE the Joneses
Joined
26,254 Posts
An AutoCal or V2 device is an interface that plugs into the OBD port, used to load tunes onto the ECM. Then it's unplugged and you run. This is what was done with your DSP install. It's linked to your truck via VIN.

A monitor does just that, it monitors different parameters that you select.

Canned tuners are just a generic spread, not tailored to you or your vehicle.
 

Premium Member
Joined
4,416 Posts
Since you just got your truck and Hook has you well informed regarding the tunes I thought Id add this thread to help you continue your education regarding that magnificent pulling machine you just purchased.

https://www.duramaxforum.com/forum/maintenance/988217-maintenance-info-suggestions-new-owners.html#post12085315

PS, IMHO you should get the tunes from a reputable tuner, not some Local Yokel. Bad tuning can be worse than no tuning and can cause significant damage to your engine/transmission.

I was in that same boat when I purchased my current truck so I dumped the tune in it in favor of a tune from a well respected tuner. Unfortunately he is no longer int he business of tuning.
 

Registered
Joined
8 Posts
Discussion Starter #12
Ok, so I don't necessarily need an AutoCal since my tunes are already loaded into my ECM. If I want a monitor to look at my temps and other gauges, I can just get the Edge Insight CTS2 84130? If that would work, I'll just do that and leave the tunes the was they are, and just keep a mental not to not launch the truck in tune 5.
 

Premium Member
Joined
4,416 Posts
Ok, so I don't necessarily need an AutoCal since my tunes are already loaded into my ECM. If I want a monitor to look at my temps and other gauges, I can just get the Edge Insight CTS2 84130? If that would work, I'll just do that and leave the tunes the was they are, and just keep a mental not to not launch the truck in tune 5.
As Hook pointed out earlier, you dont' really know what you have for tunes do you?

Your transmission can be hurt very badly with much less than a really hot tune.

You received some VERY good advice.............ignore it at your own peril................and DON"T whine when you need to pony up 5-6 grand for a transmission. :wink2:
 

Registered
Joined
8 Posts
Discussion Starter #14
I appreciate the concern. Im definitely going to be upgrading to a stage 3 transmission in the near future, so that it will be able to handle the extra power that my tunes put out, but until then, I'm just gonna keep it chill with the truck, and leave it in position 2, which seems to be a modified stock tune for better economy. As far as when I get enough saved up for a stage 3 trans, would I need additional tuning once that is installed, or will my TCM recognize it as just another stock Allison 1000?
 

LHN...We ARE the Joneses
Joined
26,254 Posts
There is a process you go thru, to re-Learn the trans shifting so it adapts to the higher outputs of the tunes.
 

Registered
Joined
8 Posts
Discussion Starter #16
Ok. I wouldn't be doing the install, I would take up to duramaxtuner near Chicago and have them do it, so I'm sure they will go through all of that. Thanks for all the info guys, this has really helped me tremendously.
 
1 - 16 of 16 Posts
Top