WenmarOpen by Wenmar Pro

Service bulletin A4524402072977_2

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10252097
Published by NHTSA2024-04-04
Manufacturer's numberA4524402072977_2
Manufacturer's date2024-03-22
NHTSA componentELECTRONIC STABILITY CONTROL (ESC):CONTROL MODULE; SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:ABS WARNING LIGHT

NHTSA's summary

This bulletin provides information when the ABS/ESC control unit cannot be reached, DTC U012100, ABS Control Module not communication.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Brakes, Driver assistance, Anti-lock brakes

Trouble codes named

U0121

Vehicles listed
AUDI E-TRON SPORTBACK2020, 2021, 2022
AUDI E-TRON SPORTBACK2023 (the catalog's model; the bulletin names a series or trim of it)
AUDI Q8 SPORTBACK E-TRON2024
AUDI SQ8 E-TRON2024 (the catalog's model; the bulletin names a series or trim of it)
AUDI SQ8 SPORTBACK E-TRON2024 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
A4524412073483_12024-04-04. Service bulletin. This bulletin provides information when the ABS/ESC control unit cannot be reached "DTC U012100 - ABS Control module no communication" is stored.
A4524392072977_12024-03-06. Service bulletin. This bulletin provides information when the ABS/ESC Control unit cannot be reached; DTC U012100, ABS Control Module no communication is stored.
A4523362072304_12024-01-04. Service bulletin. This bulletin provides information for when the ABS/ESC speed sensor has an implausible signal.
A4623452070679_12023-07-10. Service bulletin. This bulletin provides information for when one or more DC is stored in the ABS control unit related to the parking switch; DTC C100C07 and/or C100C29.
A4523332061908_42023-06-06. Service bulletin. This bulletin provides an SVM update for instances when the DTC P060C00 is stored in the electric drive control module, or DTC C051F00 is stored in the ABS control module.