L96?

Hoping this is the right section. Not up on the gas stuff.
A friend just bought an ‘08 2500HD Silverado with the 6.0 gas engine.
It won’t start and history is that it ran fine till they swapped out the gauge cluster so they then tried a bunch of ecm’s and obviously it still wouldn’t start.

I’m assuming this is an L96 engine so what model ecm should it have and where can I find a stock cal file so I can full flash it and make everything happy again?

If all factory, it'll be an LY6 and E38 ECM for 2008 (L96 is the same just has Flex Fuel).

A gauge cluster swap shouldn't matter, swapping ECMs that aren't leaned to the BCM or that have VATS disabled definitely won't allow it to start.

Questions to start troubleshooting:
1. Has the VATS relearn been done?
2. Can you read whatever ECM is in it now? If so, do the VINs match, what is the OS, and is VATS enabled?

If you have to replace the ECM, you need to make sure you have an E38 that is hardware compatible with the OS you need. I looked at a few and they use OS 12617631 for 08 Silverado 2500HD 6.0L V8 gas. If you can find an OS from the same year truck, you may be able to use EFILive and full flash a compatible file in. If not, you'll need to use GM SPS to full flash it back to stock.

LY6 then. Thanks.

I already know the fix I just need the proper cal file. The ecm has definetly not been matched or had any VATS turned off. As I said all this messing around was done before my buddy bought the truck. He and I both know what needs to be done, I’m just struggling to find out which OS is needed and where to find one.

I haven’t had a chance to try to read the ecm, I just know it’s not the original or correct one.

I use SPS to tell me what OS' should be used as there are some oddballs out there. I looked at 2 2008 2500HD 6L gas VINs, each had a different ECM OS' so you'll need to look the OS up by VIN on SPS to be sure.

If the ECM isn't from an 08 Silverado (match the hardware # and also check what OS is in it), you won't be able to solve this with EFILive alone. You need to flash it with GM SPS as EFILive doesn't flash the 2 DBW segments, only SPS does. If the current/donor ECM is from a different E38 application, like a Corvette/Camaro/etc, you can't use SPS or EFILive to make it work for this Silverado, it will brick the ECM.


(It appears you need to read/scan the T43 part number to get the correct TCM OS, hopefully that wasn't touched so you can just match the ECM!)