2021 GMC Sierra AT4 6.2L ECM swap information

[Caramonx]

I'm looking to get an ECM and send it to HP tuners in preparation for a Whipple Supercharger upgrade to save myself and the person doing the work some time.

My question is what number am I looking for?

The HP Tuners site mentions this information..

Note: Only 2019-2021 E90 ECMs are currently accepted. These include 2019 ? 2021 Serv# 12690388, 12703685, 12711852

In looking up those numbers, each one comes back to something different, so I'm unsure which one I should be ordering. Pulling back the wheel well covering and snapping a pic of my own ECM. I don't see any numbers that match what's given on the site.

Any assistance is appreciated.

[2xLS1]

Probably need to remove it from it's mounting as look for a label on the side facing down.

[blindsquirrel]

Subscribed, this should be good.

You, um, have the stuff needed to program the new ECM when you figure out where the sticker is?

edit:

snapshot_05.26_[2022.12.16_05.39.18].png

[Caramonx]

I shouldn't have to remove it, that seems unnecessary. Many folks have went through this prior to me. I'm just trying to tap someone who has done it and what they did to purchase the correct one to send in.

Of all the #'s listed, the last one seems to be the most likely part # 12711852

https://www.gmpartsbin.com/p/gmc__Si.../12711852.html

[blindsquirrel]

Many folks know how to pop the thing out of the plastic bracket and read off the Service Number.

[Kyle_Customizer]

Even if you call the dealer with your VIN number, they will likely ask you what service number you have. Just pull it and look at it.

[crankz1]

Look for a label like the one below.
Hint: It is on the backside of the ecm.

CA4F4DBF-FB09-4831-9A08-655AFDBE3ED0.jpg

[blindsquirrel]

snapshot_00.55_[2022.12.10_02.14.59].png

[Rfinn]

You will like the Whipple on your AT4, good luck with the install and tuning process.

[Estep40511]

I shouldn't have to remove it, that seems unnecessary. Many folks have went through this prior to me. I'm just trying to tap someone who has done it and what they did to purchase the correct one to send in.

Of all the #'s listed, the last one seems to be the most likely part # 12711852

https://www.gmpartsbin.com/p/gmc__Si.../12711852.html

Only two ways to get part number are to look at back of ECM or use GDS2 to go into identification information and it will give it to you. once you remove the wheelwell cover, theres two little 10mm and it comes right out.