Diesel Place banner
1 - 16 of 16 Posts

·
Registered
Joined
·
561 Posts
Discussion Starter · #1 ·
Forgive me if this has been discussed. I really don't know what to search on to see if this has been discussed.

I was just told that the early 2004 LLY trucks actually has LB7 computer control and there was something that changed in mid-year 2004.

Does anyone have any information about this?

My truck was built in late March of 2004 and I purchased it in April two weeks after it's build date. We're having trouble reading the speedometer signal and I was told that it's because what I'm using was built for the LLY and that since my truck is an early year truck I need to change how the speedometer signal is being read.

The person that told me this had no idea if my truck was an early or late 2004 model, so he wasn't trying to snow me, but he does work with development engineers that are developing systems for our trucks so I'd think this accurate.

My follow-on question is if this is true, how could that impact other systems and the performance-tuning of these systems?

Also, would it actually be LB7 software or would it be the LB7 ECM? I ask this because my computer was reprogrammed by the dealer in November of 2005.

Thanks for any answers or insight!!

Thanks!
 

·
Registered
Joined
·
16,609 Posts
The correct information is that early 04 trucks had LB7 motors and everything in them, they were called LB7's. Mid year it switched to LLY motor and all associated electronics. I doubt there are any LLY trucks with LB7 computers.
 

·
Registered
Joined
·
16,609 Posts
Jan was the switch over.
 

·
Registered
Joined
·
16,609 Posts
It actually would be pretty much impossible to have a LB7 ECM in an LLY due to the variable vane turbo etc.
 

·
Premium Member
Joined
·
20,556 Posts
The ECM's are physically different too IIRC...LLY has 3 connectors on it and the LB7 ECM only has two connectors..
 

·
Registered
Joined
·
201 Posts
Check the 8th digit in your VIN 1=LB7 and 2=LLY. Then you will know what you have!
 

·
Registered
Joined
·
451 Posts
It actually would be pretty much impossible to have a LB7 ECM in an LLY due to the variable vane turbo etc.


I see the LLY turbo called a VVT all the time on this board. Thats not what Garrett calls it. The turbo is a VNT (Variable Nozzle Turbine), same as the one on my TDI Jetta, however it's a tiny VNT-15.
 

·
Registered
Joined
·
561 Posts
Discussion Starter · #10 ·
The correct information is that early 04 trucks had LB7 motors and everything in them, they were called LB7's. Mid year it switched to LLY motor and all associated electronics. I doubt there are any LLY trucks with LB7 computers.

Nope. It was explained to me that the early LLY trucks had LB7 software and that one of the differences is the speedometer signal.

I know for sure that I have an LLY truck. The issue right now is reading the speedometer signal - it works on trucks from late 2004 to present, but not on early 2004 trucks and I was told that the LB7 software could be the culprit.

But, I had my computer reloaded in November of 2005 - so I can't figure out how that could be it!
 

·
Registered
Joined
·
16,609 Posts
To run LB7 software you would need to run and LB7 computer. An Lb7 computer with LB7 software can not control the VNT turbo.

It didn't happen, I guarantee it.

He is confusing the fact that the early 04 trucks were actually LB7's not LLY's with LB7 computers.

What are you trying to do with the speed signal? The Speed signal should be same as far as aftermarket components are concerned.
 

·
Premium Member
Joined
·
20,556 Posts
Nope. It was explained to me that the early LLY trucks had LB7 software and that one of the differences is the speedometer signal.
Explained to you by who...?

Thats just not possible. First of all, the ECMs are physically diferent. Second of all, as Max Power said, LB7 software cant control the VVT (or sorry, VNT) and thirdly, all the 2004 trucks that had LLY's were rated at 310hp/590 ft lbs. LB7 software is calibrated for 300/520...

--Ben
 

·
Registered
Joined
·
561 Posts
Discussion Starter · #13 ·
Good enough for me! Thanks for all the details!

This is for a module that will take the speedometer signals and convert for tire size (without reprogramming the computer). The fellow that told me about the programming was passing a message on from the engineer.

It didn't sound right to me, so I figured I'd go to the experts!


Thanks again!
 

·
Registered
Joined
·
16,609 Posts
Superlift's True speed?
 

·
Registered
Joined
·
1,458 Posts
I bought at 04 GMC max, and it was built in the first week of Dec 2003. That was the last week of the LB7 production. They shut down and began production in Jan 04 with the LLY, and continued with the 04 model year. So, you would be correct that you could not read the speedo signal from the early 04's as they were LB7's and the last half of the year, they were LLY's.
Still not convinced they helped things any by making that switch.
 

·
Registered
Joined
·
561 Posts
Discussion Starter · #16 ·
I bought at 04 GMC max, and it was built in the first week of Dec 2003. That was the last week of the LB7 production. They shut down and began production in Jan 04 with the LLY, and continued with the 04 model year. So, you would be correct that you could not read the speedo signal from the early 04's as they were LB7's and the last half of the year, they were LLY's.
Still not convinced they helped things any by making that switch.
Yes, yes, yes I know about all that. We're talking early 2004 LLY trucks. I'm trying to find out if perhaps the early ones still used the LB7 method for reading the speedo signal and it was later changed.

It doesn't make sense to me since we update the ECM on my truck in Nov 2005 and the module still won't read the signal. Yet the developer tells me they've seen it in other early 2004 LLY trucks.
 
1 - 16 of 16 Posts
Top