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2008 Sierra 2500 SLT, DSP5, Stage 2 turbo, searching for more info..
2 Posts
Discussion Starter · #1 · (Edited)
Hey everyone, I'm new to the forums, and relatively new to Desiel tuning. For better or worse, I bought a pre-built/tuned 2008 Sierra 2500 a couple years ago with 150k miles. It's been a good truck overall, BUT I've had a few issues with it I'm trying to sort out.

First, a little background of things I've noticed about it over the last couple years:
  • Painted Heads and ARP head studs (so they were probably off, at a minimuim)
  • Aftermarket Radiator Support/Grill, but stock-appearing radiator/intercooler (I think)
  • "Stage 2" Garret GT4094VA Turbo
  • DSP5 Switch, some lighter tunes on 4/5, smokey tune on 3, aggressive tunes on 1/2
  • Aftermarket Lift Pump by the tank
Now, I've had a few issues. The problem is, I don't know if I should be looking at the unknown tunes for issues, or looking elsewhere.
  • The dash ALWAYS says check Tire pressure on all 4 tires, I've tried a ton of different pressures
  • Pressing the Tow/Haul button has no effect
  • Pressing the Exhaust Brake button has no effect
  • I occasionally get P2563/P003A, usually under heavy load (towing or hammering down).
    • I'm wondering if this is because the aftermarket turbo shifts it's veins more that stock? I've read it popping up under idle/low load in a few threads now.
    • WOT is sometimes accompanied with P0087 in the performance tunes, apparently not getting enough fuel (a data point more than an issue)
Could any of those be the cause of a tune disabling/modifying parameters? I primarily use my truck for hauling a race car 90min through Upstate NY mountains on the regular, so I'd really like to get the tow/haul issues sorted.

I'll admit, I'm a bit nervous to bring it to a tuner not knowing whats in the engine/trans, because it does run good now. I'm assuming it's an EFILIVE tune in it, although, I'm really not sure. All I've got to go on is the DSP5 Switch on the center console kick panel.

Any information on places to continue investigating is appreciated! I'm not expecting to hash out all these issues in this thread, just determine if I should look for a broken T/H wire or look into the tunes more, check TPMS sensors, etc.

EDIT: Also, anything to look out for would be helpful. I'm a motorhead, but these Diesels are a whole new ballpark for me 馃槗

1,316 Posts
Well sounds like an interesting truck. I'll let others chime in, but as long as you don't talk about emissions deleting tunes and smoke tunes, You should be safe around here.

Super Moderator
2017 GMC Denali 2500HD, 3.5" Rough Country Lift, 305/55R20 Yokohama Geolandar A/T
3,198 Posts
Your T/H not working is most likely just the little orange wire inside the shifter being broken. I bought a new shifter for my LMM for like $45 and took a half hour to install it. That fixed my T/H intermittently not working and made it so I could manually shift again.

I don't think there was an exhaust brake button on the LMM. If you have one it's aftermarket.

I bet the previous owner put new wheels/tires on there and didn't put the TPMS sensors back in.

Lastly, I would not recommend towing without knowing what each tune does. If you're running too hot of a tune with a trailer behind you it's a quick way to smoke that transmission. The problem is it sounds like your truck is deleted, and finding a tuner to work on a deleted truck is harder than finding an honest member of Congress right now. The EPA has gutted the performance industry to the point where we are actively shutting down threads that discuss the process of deleting trucks for fear of the EPA using more of our members' posts in lawsuits.

Is there any way for you to find out who did the tuning or what the tunes are? That info is so very important.

Good luck

2008 Sierra 2500 SLT, DSP5, Stage 2 turbo, searching for more info..
2 Posts
Discussion Starter · #4 ·
Thanks for the reply MelonHead1102, I was watching out for an email but it got sent to the depths of my Inbox.

Yea, the truck is deleted, cats/mufflers/the whole 9. I live up in NY too, so they're pretty strict on emissions things up here - only way to get around it is having a large GVWR. I bought the truck from a dealer a few states away, so I've got basically ZERO info on the tunes :( I called around to a few random places I found on google, but no one told me they had seen the VIN before. I'm not really sure what to do about learning more on the tunes, but there are lots of threads about that, so I left it out of my post.

I knew tuning was getting tougher, but I didn't realize the extent to which tuners won't touch a deleted truck. I'd really like to hold on to this truck for awhile, hence trying to figure out some of it's oddities.

Good to know they didn't have an exhaust brake, I thought that was just a "standard thing". My mechanic told me the TPMS were still in there, and he tried to reset them, but still getting the alert. I'll look into the shifter thing; my manual buttons work fine, but it could just be the T/H wire that's broke.

Thanks for the info!
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