Wiring Needed For 2021 Audi Q7 to Use Brake Controller

Updated 01/12/2026 | Published 08/31/2024

Question:

2021 Audi Q7 with Towing Prep What wiring do I need for this so that the brake controller works as it would have from the factory? Would want both 4 and 7 pin connectors.

asked by: Gary J

Expert Reply:

Hey Gary,

We can get your 2021 Audi Q7 set up with a brake controller, and when you say, "what wiring do I need for this" you seemed to be referring to the Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat # ETBC7.

The wiring needed for that is just a 4-way, which will plug into the 7-way that comes with the # ETBC7. The correct 4-way for your Audi is the ZCI Circuit Protected Vehicle Wiring Harness w/ 4-Pole Flat Trailer Connector and Installation Kit # 119250KIT.

This will allow you to use a brake controller like the Tekonsha Prodigy P3 # TK78UR.

expert reply by: Kyle S

Samuel C.

1/12/2026

Hey Gary, how did the wiring setup go on your Audi Q7 using the ETBC7 kit and ZCI harness? Knowing how everything worked together with your brake controller could help others planning a similar setup.