ABS/ESP system, component overview

The following list pertains to Fig 1 .

1. Bracket for hydraulic control unit 
   • Removing and installing, see HYDRAULIC CONTROL UNIT, REMOVING AND INSTALLING 
2. Vacuum pump for brake servo 
   • Only on gasoline engines in conjunction with an automatic transmission
3. ABS Control Module (w/EDL) -J104- 
   • ABS Hydraulic Unit -N55- and ABS Control Module (w/EDL) -J104- (only on Bosch 5.7) form the hydraulic control unit.
   • Removing and installing, see HYDRAULIC CONTROL UNIT, REMOVING AND INSTALLING 
4. ABS Hydraulic Unit -N55- with ABS Control Module (w/EDL -J104- 
   • ABS Hydraulic Unit -N55 and ABS Control Module (w/EDL) -J104 (only on Bosch 5.7) form the hydraulic control unit.
   • Removing and installing, see HYDRAULIC CONTROL UNIT, REMOVING AND INSTALLING 
5. Sender 1 for brake booster -G201- 
   • Bolted onto hydraulic control unit
6. ABS Hydraulic Unit -N55- with ABS Control Module (w/EDL -J104- 
7. Rotor for right front speed sensor 
   • Checking, see CHECKING ROTOR ON REAR AXLE 
8. Right Front ABS Wheel Speed Sensor -G45- 
   • Removing and installing, see REMOVING AND INSTALLING SPEED SENSOR ON FRONT AXLE 
9. Brake Fluid Level Warning Switch -F34- 
10. Instrument cluster 
11. Anti-Slip Control Switch -E132- 
    • Location: on the center console
12. Steering angle sender -G85- for ESP 
    • Location: Installed on the steering column

      See appropriate Air Bag Restraint System article.

    • Performing zero position compensation

    See Guided Fault Finding in VAS 5051 

13. Sensor for transverse acceleration -G200 and sender for rotation Rate -G202- 
    • Location: underneath the radio
    • Removing and installing, see SENSOR FOR TRANSVERSE ACCELERATION -G200- AND SENDER FOR ROTATION RATE -G202, REMOVING AND INSTALLING 
14. Parking Brake Warning Light Switch -F9- 
    • Location: on the parking brake lever assembly
15. Rotor for right rear speed sensor 

    Checking:

    • FWD, see CHECKING ROTOR ON REAR AXLE 
    • AWD, see REMOVING AND INSTALLING SPEED SENSOR ON REAR AXLE 
16. Right Rear ABS Wheel Speed Sensor -G44- 

    Removing and installing:

    • FWD, see CHECKING ROTOR ON REAR AXLE 
    • AWD, see REMOVING AND INSTALLING SPEED SENSOR ON REAR AXLE 
17. Left Rear ABS Wheel Speed Sensor -G46- 

    Removing and installing:

    • FWD, see CHECKING ROTOR ON REAR AXLE 
    • AWD, see REMOVING AND INSTALLING SPEED SENSOR ON REAR AXLE 
18. Rotor for left rear speed sensor 

    Checking:

    • FWD, see CHECKING ROTOR ON REAR AXLE 
    • AWD, see REMOVING AND INSTALLING SPEED SENSOR ON REAR AXLE 
19. Traction Control Indicator Light-K86- 
    • Installation location: in instrument cluster
    • For further information refer to the Owner's Manual
20. ABS warning light -K47- 
    • Installation location: in instrument cluster
    • For further information refer to the Owner's Manual
21. Warning light for brake system-K118- 
    • Location: in instrument cluster in driver information system
    • For further information refer to Owner's Manual
22. Brake light switch -F- 
    • Removing and installing the brake light switch, see BRAKE LIGHT SWITCH, REMOVING AND INSTALLING 
    • Adjusting, see BRAKE LIGHT SWITCH, REMOVING AND INSTALLING 
23. Rotor for front left speed sensor 
    • Checking, see CHECKING ROTOR ON REAR AXLE 
24. Left Front ABS Wheel Speed Sensor -G47- 
    • Removing and installing, see REMOVING AND INSTALLING SPEED SENSOR ON FRONT AXLE 
Fig 1: Identifying ABS/ESP System Components
Courtesy of AUDI OF AMERICA, INC.