[Nitro66215]

This is by far not the best DIY... but it should explain what is needed to accomplish this task.

You need to have experience crimping terminal ends to create the wires needed.... Also using a multimeter

Terminal pins needed: 928999-1 - Mouser Electronics... get 100... cheaper than I can mail you some... Mouser Electronics

Crimper Tool I used: eBay Crimper tool

22 gauge wire. 4 different colors at around 5ft each. 2 sets of 2 wires twisted together.

OR... You can buy the OEM wires already terminated on a small piece of wire. GM Part: 13575859 . They aren't cheap... and you'll need at least 4. 5 if you do not have the MOST Control wire in pin 5 of the cluster connector.

4x 22 gauge barrel connectors.

Electrical tape...

Some cable ties.... and a multimeter

Disconnect the negative battery terminal so that you do not cause any shorts for the cluster and HMI.

1) Read the instructions (PDF) on removing the front of the instrument panel off. Some of that detail is in my HUD DIY. HUD DIY

The top part of the dash does not have to come off. You'll need a long extension with a 7mm to get the 2 screws on the top part of the cluster.

2) Once out, carefully remove the USB cable and the cluster connector assembly.

3) The Cluster connector....Cut the wire tie. Using a plastic trim tool... or small screwdriver, slide the connector apart. See photo.





Only strip off about 1/16" of wire to crimp on the terminal ends to the wire. Crimp the 4 wire ends on. 1 pair gets put into pin 1 and 2.... the other into pin 17 and 18. once they are cleanly clipped in... fold them over with the other wires.

Pin 5 is the MOST control wire (white / violet). In an IO5 car, this already exists. At least it did for me. If it doesn't, you'll have to create it and find this wire coming from X2 Pin 1 of the HMI module.

Slide the connector back together. (sorry... I currently do not have pictures of it completed.

4) Get your meter ready. Remove the kick panel down on the passenger side to get to the HMI module. There are 4 7mm screws holding it. Because the airbag module goes a little over the panel... it's better to remove the 2 screws near the firewall first. Then the 2 in the front towards you. Again... sorry... no pictures...



Review the MOST wiring...



Put a small piece of wire (I used a straitened out staple and wrapped a stranded wire around the outside tip of it so that I could wrap the other end around 1 end of my multimeter) into pin 2 of X2. X2 is the gray connector in the HMI module.



Now remove the door sill trim from the carpet area by the driver side door. Move the carpet out of the way and open the black plastic box around the wiring harness going back to the trunk. The AMP in the MOST wiring diagram is located in the trunk. You'll find 2 sets of white/green and gray/violet twisted pairs in this batch. 1 set goes from the radio A11 to the AMP. The other set is the return from the AMP to the HMI module. We'll be cutting this one to put the cluster in between.

Using the tip of your other end of the multimeter... slightly pierce the jacket of the white/green wire. This should short out to the HMI module pin 2 that you set the other side of the meter up to. If not... try the 2nd set of wires.

Once found, cut the white/green and the gray/violet both. With the dash apart, you should be able to fish your 2 twisted pairs of wires from the cluster down to this point of the harness.

Look at the MOST diagram and get this right....

I shouldn't have to explain how to strip and barrel connect wires....

Pin 1 of the cluster will go to the white/green wire that is going to the amplifier in the trunk. Pin 2 will go to the gray/violet going to the AMP.

Pin 17 of the cluster will go to the gray/violet wire going towards the dash (to the HMI module). Pin 18 will go to the white/green going to the HMI module.



Now reconnect the HMI module and temporarily connect the Cluster cables.

Reconnect the battery... and make sure it all works.

Double check all of the connections to make sure they are tight.

[Oramac2016]

So this restores steering wheel audio controls? (After upgrading to enhanced cluster) with 7” screen.

[Bumbleboy92]

Originally Posted by Oramac2016

So this restores steering wheel audio controls? (After upgrading to enhanced cluster) with 7” screen.

Sadly no, he has an 8" screen (IO5 which he also upgraded to IO6 for nav) and when you get the upgraded gauge cluster you need an extra wire harness for some things to work I believe like radio info, etc.

Since this thread is a few years old, Gen5DIY has already come out with a harness that does just this. It's nice to have alternative to buying harnesses though. Gen5DIY's harness

I feel your pain though, I have the 7" (IOB) and use my steering controls more than anything. I've been waiting to see if WAMS comes up with a solution in the future but currently our only saving grace is upgrading the 7" to 8" which is a great endeavor in parts (radio, HMI, dash harness, more, etc.)

[Nitro66215]

If you follow the wiring diagram, then yes... you could essentially get the controls back. It is MOST control wiring that is needed.