Retaining USB ports
 

Hello I have a 2018 50th Anniversary BRZ and a Kenwood dnx-997 xr. I have used the subaru usb retention cable but it doesn't work. USB works fine out of the headunit. There is a little usb hub that was part of the stock headunit.

When I plug into that hub it the new headunit says "Hub not supported" If I plug the head unit straight into the pink or blue usb from the brz the ports don't do anything (not even charge). Does anyone know how to at least get the usb ports working for charging?

For charging, I'd look to power the hub from something other than the radio even if it did support the hub. You'll get more amperage from a real charging circuit.

You can use either a Cig to USB adapter in the outlet behind the glove box, and mount the hub wherever, and run a cable to it.
https://www.amazon.com/Anker-Charger...dp/B07PGT7LSR/

Or, you can install a 5v converter to any 12v DC line and do the same.
https://www.amazon.com/Agile-Shop-Co...dp/B07JHH294R/

The headunit USB is really meant for data, so keeping it for things like thumbdrives is ideal.

Thank you for the suggestions. Is there no way to power the old ports just so there arent dead ports in the car? Or no way to make the factory ports the data ports?

It's strange that everything connects together correctly but nothing works. The old hub already is powered by 12v. My attempted connections are:

Old head unit to old hub to pink/blue connectors to factory ports to phone works

New head unit straight to phone works

New Head unit to Subaru USB retention cable to old hub yields hub not supported by new head unit and factory ports dont work

New head unit to subaru USB retention cable to pink or blue connectors yields nothing to factory ports (this one seems like it should work as it is just one long cable (so there must be some unconventional usb wiring on either the retention cable or the factory subaru cable or some kind of chip somewhere disabling the signal in the wire)

Leaving the old hub only connected to power and pink and blue connectors yields nothing at the factory ports. (this one also seems like it should work for powering the ports but the hub must need an active connection on the usb in side to provide power to the ports)

Approach this as two separate things. To get the factory port to work, ignore the hub. It only creates noise and confusion to your testing.

That being said, you may have a faulty USB adapter cable if your factory port never works for data, but you get a good connection when you plug directly into the new headunit. Run that down first.

I think it must be the retention cable since even bypassing the hub doesn't work. I ordered a different four pin cable today that is supposed to work in a forester. The old cable should have worked in the brz but given that the factory harness was more like the forester than the brz I'll try that one. I think its because my brz has a harmon kardin unit. Thank you for your guidance.

I tested two different subaru usb retention cables and the Toyota usb retention cable for the 86. The cable for the 86 didn’t connect. Both of the available subaru cables connected but the usb ports remained non functional. I’m giving up getting them to work.