aerostatwv

Hello,

The battery in my D4 A8L went completely dead and has been replaced with a new battery. I am now getting a "No Hill-Assist", "No ACC", and an EPB failure. VCDS indicated an EPB mechanical switch failure.

I tried clearing the DTC's but still getting the same issue. VCDS is able to engage and disengage the EPB. Any thoughts? The new battery came from Sams and has been coded as unknown to the car. All of the EPB fuses have been checked and are good.

Thanks!

viggense

I replaced my battery a few months back. I called a dealer and an independent shop where my parents take their Audi. In both cases, they required the VIN to determine the build and the appropriate battery and then coding of the battery to the car and I have had no issues. It was unclear based on your initial post whether they required the VIN to find the correct battery for your particular car but was again told by both shops there are several different batteries that were used. Hope that helps and good luck.

camargony

Just use VCDS to code the new battery, change the last digit of the existing serial number (old battery) and you are done! The battery management system will then initialize the new battery, and then you should clear all DTC`s one by one.

Battery Replacement - Ross-Tech Wiki

aerostatwv

A VCDS scan indicated the EPB switch has a mechanical failure. Coded the new battery and replaced the switch, all errors cleared.

Thank you you for all of the suggestions!