Troubleshooting Brake Light Working with Hatch Open for ZCI Wiring on 2012 Audi Q5

Updated 03/23/2020 | Published 03/21/2020

Question:

On a 2012 audi Brake lights work only with hatch open. I can find several wires that are live with the hatch closed but the trailer plug stays dead. How long does the unit have to stay unpowered to loose what it learned? Does it really have to be five seconds on to learn? If its longer is that a problem?

asked by: Fred G

Expert Reply:

Since the brake lights are only sending power to the pin on the ZCI # 119250KIT when you have the hatch opened on your 2012 Audi Q5 that leads me to believe that you have some wiring that is pinched somewhere. The ZCI should be getting constant power from your vehicle battery and then should activate those different lighting functions once they have established what wire is for what function (instructions say approx 5 seconds so a little longer is okay). I would recheck all of your connections and wiring to make sure nothing is being pinched when your hatch is closed.

The ZCI will "forget" what it learned as soon as it is disconnected from power (your vehicle battery). This is why the instructions state to connect it to constant power and not an alternating power source. So if you wanted to start all over you can basically just disconnect it from your battery power and that will reset everything.

I have attached an installation video of this kit on a 2018 Q5 that you can check out.

expert reply by: Jon G