ChadwickDMAX

Thanks Chris, just sent you an email.

Honestly, not sure if the truck came with OnStar. Never subscribed to it. I took some photos of options sticker and interior for further reference. The Bluetooth input/output on voice worked fine with original IO4 so I’m stumped as to why it’s not functioning now. *tried uploading photo of mic above driver side visor but wasn’t successful. It’s there though.

@NitroDatsik, thanks for your response buddy. I have replaced IO4, 4” screen, radio module, monochromatic DIC and standard steering wheel w/o audio controls with the following: - IO5 / 2.5HMI (Programmed by WAMS) - Radio Module (Programmed by WAMS) - Color Z71 DIC (Programmed by WAMS) - Leather wrapped steering wheel w/ full controls. (Non-heated) The replaced parts mentioned above have already been installed and plugged into the original harnesses. I am experiencing two bothersome issues currently as the truck sits: 1) Steering wheel illumination isn’t lighting up. 2) Bluetooth will connect, I can hear/receive incoming calls BUT can’t communicate. The other side can’t hear my voice. Also, no voice commands function either. (Steering wheel command and Siri AppleCarplay not receiving input) Disclaimer: I have NOT started/completed the modified wiring that needs to be done in order for steering wheel controls to properly function. Will doing this resolve the issues I’m experiencing or am I missing something? I am hiring a mobile electronics technician to do the wiring/splicing needed and want to make sure everything is done in one shot! Hopefully @Harlech , @pgamboa , @GTPprix , @richamor Or any other pros can give some further insight. ? To reiterate; I have a 2015 2500HD WT w/ IO4 option code. Huge thanks to WAMS for the programming and getting my project closer to completion.

Question: Does following this wiring schematic also give illumination to steering wheel controls? I have a 2015 WT that I upfitted pretty much exactly the same as OP did. Had been patiently waiting to get all programmed parts back from WAMS and just spent a couple hours putting together thinking at this point it was all going to be plug and play! Sadly mistaken, steering wheel controls on new leather-wrapped steering wheel aren’t interfacing with cluster or radio... This is why this community is the best because I thought I was going to be S.O.L. until I found this post! You guys are awesome. Hope someone can answer my question about illumination on steering wheel.