1990 Audi 100 Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Anti-Lock Brake System: Description: Notes

The Anti-Lock Brake System (ABS) consists of an ABS control unit, hydraulic modulator, system relays, speed sensors and necessary wiring. See Fig 1 . An ABS defeat switch is located on dashboard. The ABS defeat switch allows the driver to turn system on or off as desired. If ABS system is locked out, stopping and restarting vehicle will automatically re-engage ABS system.

Fig 1: Locating ABS Components
G90D08743Courtesy of AUDI OF AMERICA, INC.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.