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Abs Brake System, Components And Locations

Fig 1: ABS Brake System Components Location
GWWA45-10062Courtesy of AUDI OF AMERICA, LLC
  1. ASR/ESP Indicator Lamp -K155-
    • Location in instrument cluster.
    • Blinks when driving if ESP engages regularly.
    • Comes on for function test after switching ignition on and goes out after driving a short distance.
    • Comes on if there is an ESP system malfunction.
    • Comes on if there is an ABS system malfunction because ESP and ABS work together.
    • Comes on when ESP is switched off.
    • Comes on during sensor adaptation process and goes out after driving a short distance.
      • If battery was disconnected and connected.
      • Vehicle was started with jump start.
      • Battery is very weak.
    • If warning light comes on after starting the engine, there is a system-directed shut down of the system. In this case, ESP can be reactivated by switching ignition on and off.
  2. ABS Indicator Lamp -K47-
    • Location in instrument cluster.
    • Comes on for a few seconds after switching ignition on and then goes out after ABS system self-check if no malfunction was detected.
    • There is an ABS system malfunction if:
      • ABS system warning light does not come on when ignition is switched on.
      • Warning light goes out again after a few seconds.
      • Warning light comes on when driving.
    • If there is a malfunction, vehicle can be braked normally without ABS.
    • In case of a malfunction, ESP warning light comes on in addition to ABS warning light.
      WARNING:

      When ABS warning light and brake system warning light comes on, rear wheels may lock prematurely when braking.

  3. Brake System Indicator Lamp -K118-
    • Location in instrument cluster.
    • Blinks when there is a brake system malfunction.
    • Blinks when there is an ABS system malfunction.
    • Blinks when brake fluid level is too low.
  4. ABS Hydraulic Unit -N55- with ABS Control Module -J104-
    • With integrated brake pressure sensor.
      NOTE:

      Brake pressure sensor in ABS Control Module -J104- cannot be replaced.

    • Disconnecting hydraulic unit -a- and control module -b- is not intended.
    • Installed location: in right plenum chamber below engine control module.
    • Switch ignition off before separating connector.
    • Removing and Installing. Refer to ABS Control Module -J104- WITH HYDRAULIC UNIT, REMOVING AND INSTALLING .
  5. Brake System Vacuum Pump -V192-
    • Installation of vacuum pump depends on engine and transmission.
    • Location in front right engine compartment.
    • The vacuum pump is not designed to be serviced. If there is a malfunction in the pump, pump should be replaced.
    • Removing and Installing. Refer to Brake System Vacuum Pump -V192-, REMOVING AND INSTALLING .
      NOTE:

      Vacuum pump malfunctions are stored in engine control module.

  6. Brake Booster Pressure Sensor -G294-
  7. Brake Booster
  8. Brake Master Cylinder
  9. Brake Lamp Switch -F- and Brake Pedal Switch -F47-
  10. ESP Sensor Unit -G419-
    • Combined Transverse Acceleration Sensor -G200-, Rotation Rate Sensor -G202- and Longitudinal Acceleration Sensor -G251-.
    • Location under center console.
    • Removing and Installing. Refer to ESP Sensor Unit -G419-, REMOVING AND INSTALLING .
  11. Steering Angle Sensor -G85-
  12. ASR/ESP Button -E256-
    • Located in the center console.
  13. Right Front ABS Wheel Speed Sensor -G45- / or Left Front ABS Wheel Speed Sensor -G47-
  14. Front Right/Left Wheel Bearing/Wheel Hub Unit
    • ABS sensor ring is installed in wheel bearing.
  15. Right Rear ABS Wheel Speed Sensor -G44- or Left Rear ABS Wheel Speed Sensor -G46-
  16. Rear Right/Left Wheel Bearing/Wheel Hub Unit
    • ABS sensor ring is installed in wheel bearing
  17. Diagnostic Connection
    • Location under driver side footwell cover.
    • Refer to Fig 2.
  18. Parking Brake Pedal
Fig 2: Connecting VAS5051 To Data Link Connector (DLC)
GWWN40-0647Courtesy of AUDI OF AMERICA, LLC