The Bose system is lacking IMO but I thought I would share my findings with the forum. The biggest challenge with this system is it uses a new version of MOST-50 digital signal from the radio to the Bose amp. The Bose amp then Eq, filters, and time delays you speakers. Additionally your chimes, noise cancelation, and phone call all run through this amp. It tried to use a JL Fix to correct this to get a flat audio output but the comb filters Bose uses is too much for it to correct. I kept failing calibrations.
As of this post there are no audio interfaces available for this generation truck, however Nav-TV and PAC may have some in the coming months. There are some sites like LLJ customs offering complete wiring harnesses for LOC interfaces. These are well made wiring harnesses and the service they offer is great for those that just want plug and play.
Today I decided to take a look at the Bose Wiring of my 2021 Z71 Tahoe. This vehicle is equipped with a 9 speaker audio system. (2 dash spk, 2 front door spk, 2 rear door speakers, 2 rear trim speakers, and a single 6.5" sub in the center arm rest). The amp is located on the rear left side fender well. If you remove the fuse/jack cover panel you will see it mounted to the fender well.
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To there are three plugs that connect to the bottom of this amp. These will fit perfectly with the APH-GM02 harness offered by PACs.
https://catalog.pac-audio.com/catalog/amplifier-integration-harness/aph-gm02
The wiring pinout listed for this harness is incorrect for this 2021 vehicle.
I tone generated the each of the speaker pairs and re-mapped the pinouts for anyone that would like to make their own harness to interface with this system. When an interface becomes available this would allow you to amplify your speakers without cutting factory wiring or give you a solid subwoofer output signal for an aftermarket sub. Please note you will need to disable ANC mics if you add a sub.
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I did not need Harness 3. Please note the rear trim speakers are tied to the rear door speakers in parallel.
Hope this helps
