Looking for guidance and backup support before flashing LB7 (EFILive / LDS tunes / DSP5 / emissions)

[Mile_high]

Sup nerds? I need your help keeping my old truck on the road. Here’s my situation:

• Truck: 2001 LB7
• Mods: 45% SAC injectors/built trans/lift pump, DSP5 switch, EFILive
• Tuning: Purchased from LDS (they’ve since stopped offering tuning/support — offering only an unlink code at this time)

I currently have two files for those injectors:

• One that passes emissions, but all 5 DSP positions behave the same.
• One that has 5 DSP5 tunes, but won’t pass the opacity-based emissions test we have here.

The way I understand the test, they run it up to around 60 mph, then add load to drag it down to 40 mph and let it recover back up — basically a loaded-lug opacity test. To pass, the truck has to stay under 34% opacity, which means it needs to be tuned pretty soft.

I want to rework this setup so position 1 is an “on-road/emissions” tune and positions 2–5 are “off-road/performance.” The truck currently has the 5-tune DSP file flashed, and emissions are due.

My main concern right now is safely flashing the ECM again. The last time I tried, I got a voltage out of range error on the laptop and a no vehicle detected message on the FlashScan V2 (I didn’t record the exact codes, sorry). The truck was on a charger during that attempt.

I’m nervous about bricking the ECM again, so I want to line up a backup plan or shop that can bench-recover the ECM if something goes wrong.

So my questions are:

1. Is there a tuning shop or remote tuner you’d recommend who can support me if I brick the ECM?
2. Any precautions or fuse checks I should re-verify before attempting another flash? PPEI's site says to pull SEO 1 & 2 from the dash, but those are under the hood on my truck. Dash panel has SEO IGN and SEO ACCY.

Thanks, dudes!

 

[2004LB7]

If they are plugging into the obd during the emissions test then a DSP tune will fail. It has a different OS number and won't pass the compliance test. Probably why your smog tune has all 5 positions the same. Because it's a normal tune that can pass the OBD test.

Best to leave it as is

 

[1FastBrick]

I will say this.

1. the DSP5 switch is an automatic fail if it's visible.

2. That being said, They dont have all the OS from GM and GM didn't start keeping good records till around 06.

3. I have personally seen 2 LLY trucks with a DSP 5 file flashed in pass OBD2 part of the emesions test.
All the correct components were in place for the visual inspection as well.

4. I have never seen a diesel on the rollers in California. They usually do a snap test on the throttle to see if it's blowing excessive smoke. They also bring it up to like 2K and hold it there for like 10-15 seconds. This is to verify the engine is running properly and that they get a live signal from the factory ECU of the vehicle being tested.

 

[gmduramax]

Pull hvac and radio fuse or what terminal do you move under the dash to make it bypass the truck? Theres a thread somewhere about it.

 

[PureHybrid]

Pull hvac and radio fuse or what terminal do you move under the dash to make it bypass the truck? Theres a thread somewhere about it.

 

[Mile_high]

Gentlemen:

Here is what I found; are we on the right track? Same pin out, B & D, no matter if it's 2x6 or this single row 12? That's a green and an orange on this truck.

Also shown is the jumper I planned on using to follow the instructions above. Any advice or issues with this? Suggested fuse size?

 

[Mile_high]

Here is a photo from the truck. The all data repair info I found on other forums indicated it would be a 2x6 connector - not this single row 12. B is called out as dark green, which matches this. D is called out as purple, but it’s orange here. Still B and D?

 

[PureHybrid]

Not sure, haven't actually tried that. I'd say just jump it, as long as it still has comm with the ECM then it'll work

 

[Lennydmaxguy]

This is what my service info shows for the 01. Looks like it would match what you have. You'll want A & B

 

[Chevy1925]

Have yet to brick a lb7 or lly ecm using this method

“It wont brick as long as it doesn't fail during the bootblock when it's locking the ECM. If you don't lock your ECM, you can't brick it lol just pull the pcmB fuse for 2 seconds and put it back in (same as pulling batteries) lol”

This was told to me by some very very smart people in the industry

 

[Mile_high]

View attachment 133513
View attachment 133514
This is what my service info shows for the 01. Looks like it would match what you have. You'll want A & B

This is great! Thank you. Same description per JoshH's details on the 2x6 match to your table here; DLC Class 2 and ECM.

Looks like I pulled the file on a metripack 280 and not the 150.

This closely matches my truck, A and B are the same, and the others look like items that vary with options on the truck. At pin C I have dark green with white - not brown as shown here, but this truck doesn't have any power mirror options. I have no wires at pins at H, J, or L; truck has no memory/programmable seats and has the three knob HVAC controller, no digital readout or dual climate.

 

[Mile_high]

Have yet to brick a lb7 or lly ecm using this method

“It wont brick as long as it doesn't fail during the bootblock when it's locking the ECM. If you don't lock your ECM, you can't brick it lol just pull the pcmB fuse for 2 seconds and put it back in (same as pulling batteries) lol”

This was told to me by some very very smart people in the industry

I don't understand. When is the pcmB fuse to be pulled? Is that part of the recommended procedure for flashing along with this bussed cap removal and jumper?

 

[Chevy1925]

I don't understand. When is the pcmB fuse to be pulled? Is that part of the recommended procedure for flashing along with this bussed cap removal and jumper?

You were worried about bricking the ecm. There are times when the cal or full flash dont take and its stops half way through the flash. Then the truck dont work. People think their shit is bricked because it wont take another flash. Ive had it happen. You do those steps and it will take a flash again.

Only way to brick it is during the bootloader, you yank the cable out.

 

[Mile_high]

ECM was locked. It was a mess, including USPS losing the package on it's way home from SoCal.

At any rate, this all works and was a huge help. Isolating like this is the way to go. Thanks, all.

The truck made 190hp to the tires during the emissions testing and it had a cleaner result than prior years as well. I ended up finding a blown head gasket a few weeks ago, so now this junk has the fleece cylinder heads on it too. Between that and a truetrac rear end, this 25 year old truck runs better than ever right now.

 

[TheBac]

190 whp? Was that a typo?

 

[2004LB7]

They put your truck on the rollers for emissions testing? Even California doesn't do that. And, I've never seen an emissions roller capable of HP testing.

 

[Mile_high]

190 whp? Was that a typo?

No; technician said a stock truck usually runs ~130. That's all the context I have.

 

[Mile_high]

They put your truck on the rollers for emissions testing? Even California doesn't do that. And, I've never seen an emissions roller capable of HP testing.

Yes. In both counties I've registered in here in Colorado, they run it on rollers up to ~50 MPH and add load and let it recover. It sounds like a generator load testing program, ramping up and down. Lasts about a minute and a half.

From the county website regarding standards: "The allowable smoke opacity standard for all light-duty and heavy-duty naturally aspirated diesel vehicles has changed to 20% (for 5 seconds). All diesel vehicles, including heavy-duty turbocharged vehicles, which remain unchanged, must now meet this 20% opacity limit or they will fail the emissions test."

 

[2004LB7]

Yes. In both counties I've registered in here in Colorado, they run it on rollers up to ~50 MPH and add load and let it recover. It sounds like a generator load testing program, ramping up and down. Lasts about a minute and a half.

From the county website regarding standards: "The allowable smoke opacity standard for all light-duty and heavy-duty naturally aspirated diesel vehicles has changed to 20% (for 5 seconds). All diesel vehicles, including heavy-duty turbocharged vehicles, which remain unchanged, must now meet this 20% opacity limit or they will fail the emissions test."

Interesting. In California, it's a BS throttle snap test where the tech rapidly presses the throttle and watches the smoke. Highly subjective even with the "guidelines" given. No rollers

 

[2004LB7]

No; technician said a stock truck usually runs ~130. That's all the context I have.

Sounds incredibly low. I thought I remembered many stock trucks dynoing in the 200's at the wheels

Maybe it's because it's an emissions dyno and not calibrated for accurate numbers???