ABS/Electronic Stabilization Program, Bosch 8.1, Component Overview
ABS/Electronic Stabilization Program, Bosch 8.1, Component Overview
The Bosch ESP 8.1 has the following functions:
• ABS - Anti-lock braking system
• ASR - Anti-slip regulation
• EBD - Electronic brake pressure distribution
• EDL - Electronic differential lock
• ESP - Electronic stabilization program
• FBS - Fading brake support
• HBA - Hydraulic brake assist
• MSR - Engine drag torque regulation
• Emergency braking signal
• Brake disc cleaning
• Trailer stabilization
The brake system is distributed diagonally. The vacuum brake servo unit boosts the brakes pneumatically.
ABS malfunctions do not affect the brake system and the booster. Conventional brake system stays operative even without ABS. A change in braking behavior should be checked. When the ABS warning lamp comes on the rear wheels can lock-up early when braking!
Malfunction sources are reduced by direct connection of components named. The components are replaced instead of repaired.
1 - Right Rear Abs Wheel Speed Sensor G44
• Removing and Installing => [ Rear ABS Wheel Speed Sensors ] Rear ABS Wheel Speed Sensors
• can be tested in "guided fault finding" with the vehicle diagnosis, testing and information system (VAS 5051B) or (VAS 5052)
2 - Left Rear Abs Wheel Speed Sensor G46
• Removing and Installing => [ Rear ABS Wheel Speed Sensors ] Rear ABS Wheel Speed Sensors
3 - ESP-Sensor Unit (-G419-)
• 9 Nm
• Component location: under the left seat
• Removing and Installing => [ ESP Sensor Unit and ESP Sensor Unit 2 ] ESP Sensor Unit and ESP Sensor Unit 2
• Combined transverse acceleration sensor G200, rotation rate sensor G202 and longitudinal acceleration sensor G251.
• can be tested in "guided fault finding" with the vehicle diagnosis, testing and information system (VAS 5051B) or (VAS 5052)
• Observe installation instructions
• Check the arrow in the direction of travel when installing
4 - Brake Lamp Sensor
• Component location: on brake pedal
• Removing and Installing => [ Brake Lamp Sensor ] Service and Repair
• can be tested in "guided fault finding" with the vehicle diagnosis, testing and information system (VAS 5051B) or (VAS 5052)
Cannot be reused after removal.
5 - Brake Pedal
• with bracket for the brake lamp sensor
• Removing and Installing, with Manual Transmission => [ Brake Pedal, with Manual Transmission ] Brake Pedal, With Manual Transmission
• Removing and Installing, with Automatic Transmission => [ Brake Pedal, with Automatic Transmission ] Brake Pedal, With Automatic Transmission
6 - Electro-Mechanical Parking Brake Indicator Lamp
• Located in the tachometer.
• lights up when the parking brake is engaged and the ignition is switched on,
• lights up for 20 seconds when the parking brake is engaged and the ignition is switched off,
• blinks after engaging the parking brake if the brake pressure is not sufficient to prevent the vehicle from rolling.
7 - Brake System Warning Lamp (K118)
• Located in the tachometer.
• Turns on with the ABS indicator lamp when the ABS system malfunctions
• blinks when the brake fluid is too low
• Blinks when there is a malfunction in the brake system
The malfunction is indicated more precisely when the "SET button" in the instrument cluster is pressed.
8 - Abs Warning Lamp (K47)
The indicator lamp monitors the ABS and the Electronic Differential Lock (EDL).
• Component location: in the tachometer
• lights up for several seconds when ignition is switched on and goes out after an automatic ABS system self-check if there are no malfunctions in the ABS system.
• There is an ABS malfunction if the indicator light:
• does not light up when ignition is switched on,
• does not go out after a few seconds,
• lights up while driving.
• ABS malfunctions have no effect on the brake system. However, a change in braking behavior should be checked.
The Electronic Differential Lock (EDL) and ABS work together. The ABS indicator light lights up when the EDL malfunctions.
9 - ABS/ESP Control Lamp (K155)
• Component location: in the tachometer
• blinks when driving if ESP/ASR engages regularly.
• comes on when ignition is switched on and goes out after a short self-check.
• 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 the ASR is switched off.
• lights up during sensor programming if:
• the battery was disconnected and connected,
• vehicle was started with jump start,
• the battery is too weak.
• after the sensor programming procedure, the ESP light goes out after driving a short distance.
10 - Left Front Abs Wheel Speed Sensor G47
• Removing and Installing => [ Front ABS Wheel Speed Sensors ] Front ABS Wheel Speed Sensors
• can be tested in "guided fault finding" with the vehicle diagnosis, testing and information system (VAS 5051B) or (VAS 5052)
11 - Abs Hydraulic Unit With Abs Control Module J104
• Removing and Installing => [ ABS Hydraulic Unit with ABS Control Module ] Service and Repair
12 - Return Ring
• Removing and Installing => [ Steering Angle Sensor ] Service and Repair
13 - Steering Angle Sensor (-G85-)
• Component location: Installed in coil ring with slip ring on steering column => 69
• Removing and Installing => [ Steering Angle Sensor ] Service and Repair
• Perform zero adjustment
Vehicle diagnosis, testing and information system (VAS 5051B) or (VAS 5052)
14 - Right Front Abs Wheel Speed Sensor G45
• Removing and Installing => [ Front ABS Wheel Speed Sensors ] Front ABS Wheel Speed Sensors
15 - ASR/ESP Button (E256)
• Component location: Inside center console
• Switches the ASR off and on
16 - Audi Hold Assist Pressure Switch
• Located in the center console
• Function => [ Audi Hold Assist ] Audi Hold Assist
• Removing and Installing => [ Audi Hold Assist Switch ] Service and Repair
17 - Parking Brake Pressure Switch F234
• Located in the center console
• Removing and Installing => [ Electro-Mechanical Parking Brake Switch ] Electro-Mechanical Parking Brake Switch
18 - Diagnostic Connection
• Component location: cover in driver footwell
