How To Do a VATS Relearn After Replacing Your L5P Duramax E41 ECM

DURAMAXTUNER.COM has put this guide together for performing a VATS relearn on your 2017, 2018, 2019, 2020, or 2021 L5P 6.6L Duramax. Our experience has been that if this process does not work, you will need to reach out to local HPTUNERS dealer or experienced diesel shop for in-person support. At this time, we are not able to offer extensive phone support for the L5P VATS relearn process.


- You will need an MDI2 GM Tool, an ACdelco techline account & lic, and a windows based computer. 

- For 2017-2019 Trucks if you follow these instruction you will only need 1 key. If you have a 2020 or newer truck with a keyless remote, or mess this procedure up, then you will need both keys.

Before you start:

-Insure the Vin Number is Correct.

-Insure the battery is charged

-Insure you have at least an hour available.

Note- A "vats on tune" is not required to do this procedure. 

1. Download/Install/Run Techline connect

2. Drop Down to Replace & Reprogram

3. Find the Immobilizer Relearn procedure

Step 2

4. Follow the steps

step 3

5. **VERY IMPORTANT** --> Select Engine control module IMMO LEARN. Anything else will require much more work and headache.

step 4

6. Follow the prompts on the screen. For 2020+ Trucks 1 key fob must be placed in the "key hub", the other must be outside of the vehicle.


7. Follow the prompts on the screen. The first part of this process should take 12 minutes.

step 5

8. After the 12 minute security cycle, the truck will continue to walk you through-key on, key off, etc.

9. Yes.

step 6

10. If you have a 2017-2019 Trucks you can select no and follow the prompts on the screen. For 2020 trucks with Push to start you must click yes.

11. 2020 Trucks  you will need to relearn the 2nd key. Your dash may refer to this as "key3"

12. Place your first key outside of the vehicle, and place your second key into the cup holder.

13. Follow the remaining steps. The process should not take longer then a couple minutes. At the end when you have learned your 2nd key. You can click no for more keys, and follow the steps until you are done.

14. When completed, insure the vehicle starts with both keys. Also, insure the remote start works. 


**For any questions regarding the tuning of your vehicle, please call 815-568-7920.**