3500 srw programming to 2500

[hogbody]

I would imagine that due to factory restrictions it would not be possible, but wouldn't it be nice for those that have put 265's on their trucks to be able to have the ECM programmed with the 3500 single rear wheel programming (as they have 265's also.)

That way the speedo would work....the DIC would work and the other programs that affect operation would be adjusted to reflect the increase tire size.

Probably can't be done but it would be nice.......

[Mark Rinker]

Your dealer should be able to do this for you. I have watched over the shoulder of my local tech and its all possible. The VIN might be the stumbling block - maybe one of our GM Techs can chime in here...I had my 2001 ECM reflashed with 2002 programming, and to get it to work, my tech actually entered the VIN from my other truck, a 2002...in theory my Diablosport should now work on either truck, but I haven't yet tried it.

You should be able to adjust for the increased tire diameter with a number of aftermarket 'tuners' available as well, even if you aren't interested in running their performance tune for everyday use. Find a friend or an Ebay Diablosport for $100.

[Kennedy]

The problem here is that it's not "ethical" for the dealer to do this. What CAN be done is to flash the stock calibrations from a 3500 truck (VIN and all) into your ECM, BUT now there is a mismatch and this could cause major headaches down the road. You'd also get the calibration for the 34 gallon fuel tank which may or may not create problems. We alter speed signal stuff with our custom tuning, but keep the VIN original.

I'm not sure how Mark's Tech managed to flash a 2002 VIN into a 2001 ECM with a Tech 2 though. Every time that I've done it and everyone else that I know has found that it wipes out the ECM...