Head lights adjustment

[Hey you]

OK, my 21 Tahoe LT has the Led headlights.
I decided to adjust my headlights; they were too low. The passenger side adjusted fine with the adjuster... but the driver side would not. Turning the plastic "thingy" (Technical term!) resulted in it moving down regardless of which way I turned the white plastic thingy. So it was at its max height and would not go up to match the passenger side.
Anybody have this issue? Will I have to buy a replacement headlight and housing? Looks like the bumper will have to be removed to install a new assembly.

I also installed LED turn signal and backup bulbs on the rear... so far they work Gr8.

Finally, I have the OBD plugin for the cylinder disable that I used on my 2015. That car would display what mode the cylinders were operating in 4, 6, or 8 on the Driver DIC display.
Tried it with the 2021, and cannot find any display to see if its working, as I prefer to keep all the cylinders operational.

Thanks in advance, hope everyone had a Gr8 Xmas and New Year.

 

[Big Mama]

Is that area dented? Just wondering if it got pushed in so you it won’t adjust up. For the DFM I think since it can turn off any number of cylinders 1-7 it isn’t available to see like the previous AFM .

 

[Hey you]

There was not damage, but the driver side headlight did drop to the bottom of the housing, complete disconnect from the adjuster mechanism. After more searching here, this problem seems to be quite common, after searching (headlight adjuster repair) I was able to remove the mechanism, apply liberal amount of epoxy and re-assemble. Seems to be holding after adjustments. Note... the warning of do not drop the adjuster mechanism!
The DFM module did not display the actual number of cylinders firing on my 2015 Tahoe, it did that prior to purchasing the plug in. After which it always displayed 8 cylinders firing. I cannot find how to display the cylinders firing on the newer 2021 I just upgraded to! I am not sure of the difference between AFM and DFM, but could that be the reason?

 

[Big Mama]

Nice repair job. I think that’s why you can’t see cylinder deactivation. AFM in early days shot off 4 cylinders. DFM can shut off any number of cylinders 1-7 not just even numbers or the same 4. I still think it’d be easy enough to display though. I’m going to see what’s in development through the infotainment screen. If you go to settings then tap the about button rapidly you’ll see what’s not otherwise visible. Be careful though.

 

[CMoore711]

The OBD dongle you used to plug into your 2015 and deactivate AFM will not work on your newer 2021 model. They're completely different in a couple ways; As @Big Mama indicated the 2015-2020 models used AFM and the newer 2021+ models use DFM. You can do some searching for the differences, but in short AFM would operate on all 8 cylinders or just 4 cylinders, whereas DFM has the ability to operate off any number or combination of cylinders. Additionally, the the ECM software on the newer 2021+ models is different and so requires a different DFM disabling module.

There are some DFM disable options available from Range as well as a Carbyte brand option for the newer 2021+. There are various threads here on the forums you can search for with members who have used them and their feedback.

 

[Big Mama]

The OBD dongle you used to plug into your 2015 and deactivate AFM will not work on your newer 2021 model. They're completely different in a couple ways; As @Big Mama indicated the 2015-2020 models used AFM and the newer 2021+ models use DFM. You can do some searching for the differences, but in short AFM would operate on all 8 cylinders or just 4 cylinders, whereas DFM has the ability to operate off any number or combination of cylinders. Additionally, the the ECM software on the newer 2021+ models is different and so requires a different DFM disabling module.

There are some DFM disable options available from Range as well as a Carbyte brand option for the newer 2021+. There are various threads here on the forums you can search for with members who have used them and their feedback.

Thanks for confirming that. My reply was a guess of sorts after a lot of digging.

 

[Hey you]

Thanks Guys, I am going to look into that. Hope to be able to keep it running on all 8, all the time.

 

[Hey you]

OK, going back to the headlight adjuster issue. After two attempts with the epoxy, which has failed after time, I decided to do the other method used by several members.
I drilled a hole in the housing, cleaned up the excess old epoxy, and after drilling a pilot hole inserted a small screw being careful not to make contact with the black plastic
shaped ball that turns with the adjuster mechanism. The pics and descriptions from other members really helped with the process, and my thanks to all who contributed,
West 1, Tahoe Rob, New Guy, Bdbdzz and everyone else who posted info on this problem.
Too bad GM does not own up to this issue, and do the right thing.

This repair seems to be the way to go.