Upgrade '16 Denali to HDMI input from '17 models?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

cmatt

Full Access Member
Joined
Apr 29, 2009
Posts
601
Reaction score
646
I may be way off base, but is this as "simple" as swapping the modules and the old harness for the new harness that you posted earlier @cmatt ?

Almost. There’s one more usb that needs to be swapped in the dash.


Sent from my iPad using Tapatalk
 

cmatt

Full Access Member
Joined
Apr 29, 2009
Posts
601
Reaction score
646
So I wanted to document my progress so far with this. It can be done physically. As of the writing of this post, I am still working on the HDMI functionality.

My vehicle is a 2015 Yukon SLT with RPO U42 which is the rear entertainment system with RCA A/V inputs.

To swap in the X82 audio/video adapter module with the additional usb and HDMI outlet from a 2017+ suv, it will require swapping a usb cable in the dash, adding a usb cable to the center console and using a different connector for the module.

To obtain the usb cables, I had to purchase a center console harness and a dash harness. If any of you can help source the individual cables, it would be a great help.

Center console usb cable - 33183241
9cb0a279ca83de25f7f31a64708c0ffd.jpg

Dash harness usb cable - 33308529
07d2a933d989b978f0680b323836a955.jpg

This is what the specific LVDS usb cable that needs to be swapped out looks like out of a 2017+ suv.

e55cdc0efd35f7f15a39974c5cd8b65e.jpg

Notice the HMI bypass module. That was added on 2017+ as a safety feature. I believe it allows a backup reverse camera signal. However, we won’t need it for our purposes.

The other difference is the split off of the DVD player to the center console. 2015s-2016s don’t have that. It brings the LVDS signal to the center console. It then connects to a new usb cable in the center console that connects to the X82 A/V adapter in the rear of the center console.

In the 2015-2016, the blue LVDS usb cable goes from the HMI and connects to the back of the front screen here. You can see it’s a double usb. It travels to the DVD player and terminates there.

a79245af36ea4fdc8556c0f5e5979deb.jpg

Rear of DVD player

19edf9c1c47093b4a3ee3df243e75d72.jpg

On the 2017+, you can see the cable split off again from the dvd

e816a71df9d51baace5eff5890e7eded.jpg

I routed the 2017+ cable along the OE path and plugged everything in.
04276551a8efd1a3aedd19e8799ea266.jpg

If you recall, I said we don’t need the HMI bypass module. The issue becomes the keyed end to the usb. The HMI module is looking for a blue usb plug, but we end up with a gray plug.

f8887c0d26d35bca334fce7f90dec984.jpg

If you look at the keying, it’s very similar. I removed the areas preventing the gray plug from seating to the HMI with a knife.

29eac56bfb38919d73aca0bc2b1bf116.jpg

After that it plugged in fine.

eb5a16fd927eb4618f44e7a9720a3c38.jpg

I then routed the center console usb cable.

8207145fe84925439ad666ce45ca7168.jpg

9980712a5479ec3bfd3c7355d12a749b.jpg

The next task is the 6 pin connector (5 spots used). 2015-2016 has a 12 pin (only 10 spots used). Those additional 5 wires carry the RCA signal and are not needed with the 2017+ A/V adapter. The wires needed are for the power, ground and wireless headphone signal.

7801b9e6838371dedad61288ca07720a.jpg

d66b88b1d208bceccd4babbea5c33dea.jpg



There are a couple ways to accomplish getting the proper wires connected. I am working on a pigtail. The issue is that @pgamboa nor I can’t find a mating 12 pin connector. So I’m left with plugging in the individual wires.

85c91e9446e8e12bc51af462f17fc5cc.jpg

I think a better method for now is just removing the needed wires from the 12 pin and landing them in the 6 pin connector.

Remove the CPA on the 12 pin and use a micro flathead screwdriver to release the terminals.

da8b400ce57e1fcf5ed284baa2e269e6.jpg

47c5b0eb348f3267d8f1078157614885.jpg

Then remove the CPA from the 6 pin connector, land the terminals and reinstall the CPA.

840dfb46216539dba7975d5815dc8040.jpg

c39a615c6114008fca4728b11e77419d.jpg

So both USB ports work including charging.

80c2ee411808dce7c7f46d081c7eac4e.jpg

For the HDMI, I believe the signal is carried along the newly installed blue LVDS usb cable. However, the system doesn’t know to look for it. It doesn’t show as an option in the media menu. So, is it the HMI, dvd or radio that needs to recognize it? Is it swapping out one of those components? Is it a programming thing that @GTPprix can add? I need a fresh set of eyes on this.


Sent from my iPad using Tapatalk
 
Last edited:

mfennema

TYF Newbie
Joined
Sep 10, 2018
Posts
27
Reaction score
10
Can you layout what the original connections look like from the back if the '15 module and where they go?

Sent from my SM-G950U using Tapatalk
 

cmatt

Full Access Member
Joined
Apr 29, 2009
Posts
601
Reaction score
646
Can you layout what the original connections look like from the back if the '15 module and where they go?

Sent from my SM-G950U using Tapatalk

You mean this?

64934ca1501944fe90a7f99ef7425baa.jpg

On the 2015-2016, the usb at the module and in the console compartment come together in this double usb plug at the front of the center console and connect with the black usb cables in the dash harness. It connects to the black plugs on the dvd and HMI.

a1b97977717cf5b340b473d7115d26fb.jpg


Sent from my iPad using Tapatalk
 

cmatt

Full Access Member
Joined
Apr 29, 2009
Posts
601
Reaction score
646
Some additional thoughts I had on the matter:
I’m thinking the circuit board in the A/V adapter at the back of the console is processing the HDMI signal and sending it down the blue LVDS usb cable that was added. From that direction, it enters the dvd first, then on to the front screen and HMI. The signal can also head out to the overhead screen from the dvd. I’m wondering if the DVD player needs to be from a 2017+. Thoughts?
 

mfennema

TYF Newbie
Joined
Sep 10, 2018
Posts
27
Reaction score
10
That could be a real possibility. I'm also wondering if there is something in the HMI that needs to be updated also??

Sent from my SM-G950U using Tapatalk
 

Darren Trokhan

TYF Newbie
Joined
Oct 16, 2018
Posts
2
Reaction score
1
cmatt,

Do you have any other relevant wiring diagrams that you haven't shared yet?

It seems like you have the wiring connected properly. It's just a matter now of getting everything to communicate properly. I wonder if there is some way to let the system know that an HDMI module is connected that doesn't require a firmware change.

The way the DVD and HDMI input modules are spliced together makes me think that you could switch to DVD mode and possibly see the output of your HDMI adapter. Although the system might kill power to the HDMI board when you are trying to watch a DVD.

Can you tell if you are actually getting power to the DVD module? Does the power go on and off as you switch between input modes for the display?

Also, where is the HMI module located? Is it easier to get to than the DVD player?



DPT
 
Last edited:

cmatt

Full Access Member
Joined
Apr 29, 2009
Posts
601
Reaction score
646
cmatt,

Do you have any other relevant wiring diagrams that you haven't shared yet?

It seems like you have the wiring connected properly. It's just a matter now of getting everything to communicate properly. I wonder if there is some way to let the system know that an HDMI module is connected that doesn't require a firmware change.

The way the DVD and HDMI input modules are spliced together makes me think that you could switch to DVD mode and possibly see the output of your HDMI adapter. Although the system might kill power to the HDMI board when you are trying to watch a DVD.

Can you tell if you are actually getting power to the DVD module? Does the power go on and off as you switch between input modes for the display?

Also, where is the HMI module located? Is it easier to get to than the DVD player?



DPT

There aren’t any other wiring diagrams I’ve come across yet.

I think it is a programming thing with the HMI. Remember, my 2015 HMI is looking for the rca inputs. It doesn’t know the HDMI exists. I’m still troubleshooting it.

Yes, everything is getting power. I don’t believe it is switching on and off.

The HMI module is behind the glovebox and below the passenger airbag. You can get to it by removing the same cover that accesses the cabin filter.
 

Jptri

TYF Newbie
Joined
Nov 2, 2018
Posts
8
Reaction score
3
cmatt..
Have you had any revelations? I'm thinking it's a combination of a newer DVD player (84409491) and a newer HMI module (84331776 or 84546904) to make it work.

I have a slightly different problem. I have a 2018 with RSE (hdmi input). The input is not displaying any res higher than 480p. Signal from a Roku appears zoomed in to just the bottom left portion of what the Roku would normally put out. Yet, other 2018 Tahoes on the dealer lot display 720p just fine. I'm thinking the problem is either my version of the DVD player installed during the build (not support more than 480p from the hdmi input coming to it) or the HMI module. I have 84364936 which is an earlier build than the ones listed above. GM infotainment support is aware of the issue. GM tech support is telling the dealer techs that replacing the HMI won't fix the issue. Of course my response to them is "then what will make it output 720p... if you're so confident it's not in the HMI then where is the problem?". I haven't received that answer yet but will pass along if I find out.
 

Seanjordan20

TYF Newbie
Joined
Jun 10, 2017
Posts
8
Reaction score
0
Cmatt have you had any luck with figuring it out. I have a 15 Denali and have upgraded my HMI and DVD to the newer models. I am wanting to start the cabling for the module and don’t want to tear anything apart if it’s not going to work. Please let me know
 

Forum statistics

Threads
128,791
Posts
1,805,528
Members
91,775
Latest member
labans
Top