LMM Programming History & CVN's Explained

[Cougar281]

Currently the LMM is the only vehicle this programming history is activated on, but it would be a safe bet this will expand in to all new models over the coming years.

I think his point was that a heavily modded tune was showing a stock CVN...

[Duramax 6.6L]

I don't know this first hand, But a very good friend of mine that works at a Chevrolet dealer that is performance friendly, has never been able to tell if a truck has been programed, even with a hand help programmer. I know that this dealership has warranted a few transmissions and transfer cases, that were blown because of modifications. This dealer does not even care if you have a lift kit installed with oversized tires

I have sold to this dealer and they have installed quite a few finger stick / blocker plate combos.

[MMLMM]

current solution right now is the fry your ecm and tow truck in for service....yes, no?

[vortecfcar]

current solution right now is the fry your ecm and tow truck in for service....yes, no?

Don't click the 'Dealer Visit' button on the DVT panel until you blow out the dipstick tube.

[Redline Motorsports]

I guess install a pre-computer controler, like Edge etc...., will beat that system......

[GMPX]

Ross.

I'm getting the same CVN with a HEAVILY modified tune and with a stock tune flashed with a Tech2.

This is on a 2005 Duramax.

Seems the Tech2 doesn't "calculate" the CVN on this model, it just reads it. If EFILive does not alter those 2 bytes, it won't change? Dunno for sure.

If it's the ECM that is generating these CVN's and the Tech2 just reads their stored location, the ECM should have a value that tells the Tech2 where to look for these. Move the pointer?

Pat, the LMM CVN system is a little more complex. The LLY does use a simple adding checksum system, not CRC, I think it is just reporting the adding checksum value to the TechII. Having said that, I thought it would change!
I know what you mean on fooling the ECM to just send back a known value, however, that means that we would need to know the CVN for EVERY segment GM ever released for the LMM and store them in the ECM somewhere, too hard.
Did you get my Email on this BTW?

Cheers,
Ross

[Cougar281]

Pat, the LMM CVN system is a little more complex. The LLY does use a simple adding checksum system, not CRC, I think it is just reporting the adding checksum value to the TechII. Having said that, I thought it would change!
I know what you mean on fooling the ECM to just send back a known value, however, that means that we would need to know the CVN for EVERY segment GM ever released for the LMM and store them in the ECM somewhere, too hard.
Did you get my Email on this BTW?

Cheers,
Ross

How about if EFILive was programmed to read the "current" GM CVN, then program it into the ECM with the redirect for the Tech2?

[GMPX]

How about if EFILive was programmed to read the "current" GM CVN, then program it into the ECM with the redirect for the Tech2?

My head hurts just thinking about that process

Without saying too much we've made some great progress with Bosch ECM's over the last few weeks. Once we get our full flashing working for these ECM's we will probably be able to offer a 'reset ECM' option.

Cheers,
Ross

[fire0021]

current solution right now is the fry your ecm and tow truck in for service....yes, no?

didint work on mine i put a completley new un modded ecm in my truck and it still showed all my old check sums from my previous ecm. wich meens to me the info is stored also somewhere else. ambey the tcm not sure

[Cougar281]

Probably not TCM.... GPCM would be my guess.