Contents Wiring diagrams Section: Anti-Lock/traction Control All sections

Anti-Lock Brake System (coupe) Audi A5 I

Anti-Lock/traction Control 17 illustrations ~3960 words

ANTILOCK BRAKE SYSTEM (ABS)

WARNINGThe anti-lock brake system is generally maintenance-free. Testing, assembly, and repair work may only be performed by qualified personnel. By not observing the points described in the repair information, the system can be damaged and vehicle safety could be compromised.
  1. Before performing repair work on the anti-lock brake system, determine the cause of the malfunction using On-Board Diagnostics (OBD).
  2. When installing a new hydraulic control unit, use the vehicle diagnostic tester VAS 5051B or VAS 5052 to check the coding.
  3. Switch ignition off before installation work. If the radio in the vehicle is coded, find out the radio code before disconnecting the battery ground cable.
  4. When working with brake fluid, observe relevant safety precautions and notes, refer to «BRAKE FLUID»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#general-technical-data-brake-system-coupe__brake-fluid) .
  5. Bleed the brake system with the brake charger/bleeder unit VAS 5234 for all work that requires opening the hydraulic system. High and low pressure testing should also be performed on the brake system, refer to «HIGH AND LOW PRESSURE TESTING»(/audi/a5/i-2007-2011/remont/mechanical-hydraulic/#hydraulic-components-brake-system-coupe__high-and-low-pressure-testing) .
  6. During the final road test, ensure that a ABS-controlled brake test is performed at least once (pulsation must be felt at the brake pedal). refer to the vehicle diagnostic tester VAS 5051B or VAS 5052.
  7. Absolute cleanliness is required when working on the anti-lock brake system. Do not use any products which contain mineral oil, such as oils, greases etc.
  8. Thoroughly clean all unions and the adjacent areas before loosening. Do not use aggressive cleaning agents such as brake cleaner, fuel, thinners or similar chemicals.
  9. Place parts that have been removed on a clean surface and cover.
  10. Carefully cover or seal open components, if repairs are not carried out immediately. Use the plug from repair set 1H0 698 311 A.
  11. Only use lint-free cloths.
  12. Only unpack replacement parts immediately prior to installation.
  13. Only use Original Parts still in their original packaging.
  14. Do not work with compressed air and do not move vehicle while the system is open.
  15. Make sure brake fluid cannot get into the connector.

VEHICLE DIAGNOSTIC TESTER VAS 5051B/ 5052 CONNECTING AND SELECTION FUNCTIONS

Special tools and workshop equipment required

  1. Vehicle Diagnostic Tester

Connect the VAS 5051/5a diagnostic cable connector to diagnostic connection.

Scheme 20

Scheme 20

Switch tester on.

The tester is ready for use when the vehicle symbol is displayed.

Turn on the ignition.

Touch the field / the button on the screen: Guided Fault Finding.

Select in succession

  1. Brand
  2. Type
  3. Model year
  4. Version
  5. Engine Code

Confirm data entered.

Wait until tester has checked all control modules in vehicle.

Press the go to button and select "function/component selection".

Select "suspension" on the display.

Select "brake system" on the display.

Select "001 - OBD-capable system" in the display.

Select on display "Antilock brake system...".

Select on display "Function".

Now, all possible functions of the anti-lock brake system installed in the vehicle will be displayed.

Select desired function on display.

ABS/ELECTRONIC STABILIZATION PROGRAM (ESP) OVERVIEW, BOSCH

The Bosch ESP 8.1 has the following functions

  1. ABS - Antilock braking system
  2. ASR - Anti-slip regulation
  3. EBD - Electronic brake pressure distribution
  4. EDL - Electronic differential lock
  5. ESP - Electronic stabilization program
  6. FBS - Fading brake support
  7. HBA - Hydraulic brake assist
  8. MSR - Engine drag torque regulation
  9. Emergency braking signal
  10. Brake rotor cleaning
  11. Trailer stabilization

The brake system is distributed diagonally. The vacuum brake servo unit boosts the brakes pneumatically.

Note. 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.

Scheme 21

Scheme 21
  1. Right Rear ABS Wheel Speed Sensor -G44- Removing and Installing, refer to «RIGHT REAR ABS WHEEL SPEED SENSOR -G44- AND LEFT REAR ABS WHEEL SPEED SENSOR -G46»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__right-rear-abs-wheel-speed-sensor) Can be tested in "guided fault finding" with the vehicle diagnostic tester VAS 5051B or VAS 5052.
  2. Left Rear ABS Wheel Speed Sensor -G46
  3. ESP-Sensor Unit -G419- Component location: under the left seat. Removing and Installing, refer to «ESP SENSOR UNIT -G419»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__esp-sensor-unit-g419) . 9 Nm Combined transverse acceleration sensor G200, rotation rate sensor G202 and longitudinal acceleration sensor G251. Can be tested in "guided fault finding" with the vehicle diagnostic tester. 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, refer to «BRAKE LAMP SENSOR»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__brake-lamp-sensor) . Can be tested in "guided fault finding" with the vehicle diagnostic tester VAS 5051B or VAS 5052 Cannot be reused after removal.
  5. Brake Pedal With bracket for the brake lamp sensor. Removing and Installing, Manual Transmission, refer to «BRAKE PEDAL, MANUAL TRANSMISSION»(/audi/a5/i-2007-2011/remont/mechanical-hydraulic/#mechanical-components-brake-system-coupe) . Removing and Installing, Automatic Transmission, refer to «BRAKE PEDAL, AUTOMATIC TRANSMISSION»(/audi/a5/i-2007-2011/remont/mechanical-hydraulic/#mechanical-components-brake-system-coupe__brake-pedal-automatic-transmission) .
  6. Electromechanical 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 Indicator 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. NOTE: The malfunction is indicated more precisely when the "SET button" in the instrument cluster is pressed.
  8. ABS Indicator Lamp -K47- NOTE: 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. NOTE: The Electronic Differential Lock (EDL) and ABS work together. The ABS indicator light lights up when the EDL malfunctions.
  9. ASR/ESP Indicator 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. Comes on 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, refer to «RIGHT FRONT ABS WHEEL SPEED SENSOR -G45- AND LEFT FRONT ABS WHEEL SPEED SENSOR -G47»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__right-front-abs-wheel-speed-sensor) . Can be tested in "guided fault finding" with the vehicle diagnostic tester VAS 5051B or VAS 5052.
  11. ABS Hydraulic Unit with ABS Control Module -J104- Removing and Installing, refer to «ABS HYDRAULIC UNIT -N55- WITH ABS CONTROL MODULE -J104»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__abs-hydraulic-unit-n55-with-abs) .
  12. Return Ring Removing and Installing, refer to «STEERING ANGLE SENSOR -G85»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__steering-angle-sensor-g85) .
  13. Steering Angle Sensor -G85- Component location: Installed in coil ring with slip ring on steering column. Removing and Installing, refer to «STEERING ANGLE SENSOR -G85»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__steering-angle-sensor-g85) . Perform zero adjustment, using the Vehicle diagnostic tester.
  14. Right Front ABS Wheel Speed Sensor -G45
  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, refer to «AUDI HOLD ASSIST»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__audi-hold-assist) . Removing and Installing, refer to «AUDI HOLD ASSIST SWITCH»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe) .
  17. Parking Brake Pressure Switch -F234- Located in the center console. Removing and Installing, refer to «PARKING BRAKE SWITCH -F321»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe) .
  18. Diagnostic Connection Component location: cover in driver footwell.

Scheme 22

Scheme 22

AUDI HOLD ASSIST

Depending on the model, the vehicle may be equipped with Audi Hold Assist (AHA).

Function

The function assists the driver if the vehicle must remain stopped frequently or for long periods of time when the engine is running.

When the vehicle is stopped and the function is activated, the vehicle is held in place by Audi Hold Assist (AHA).

The driver can release the brake pedal.

The vehicle is held in place by maintaining the brake pressure on all four wheels in ESP.

To prevent the ESP solenoid valves to overheat when stopped for long periods of time, the rear electromechanical parking brake automatically takes over braking when the solenoid valves reach a temperature of 200° C.

The point when the brakes automatically release is based on the following information

  1. Engine speed
  2. Angle
  3. Gear engaged.
  4. With manual transmissions, distance on the clutch pedal through the clutch sensor.
  5. With automatic transmissions, through converter release.

To prevent the vehicle from rolling back, the brakes are only released when there is sufficient engine torque.

Activation

The following conditions must be fulfilled to switch the "stand by" function on

  1. Driver wearing seat belt.
  2. Engine running.
  3. Driver door closed.
  4. No ESP and electronic parking brake malfunctions.

The switch -2- in the center console activates the function.

Scheme 23

Scheme 23

The switch indicates the operating conditions.

  1. Deactivated - the LED in the switch is off.
  2. Stand by - the LED in the switch is on.
  3. Active - the LED in the switch is on and the instrument cluster display shows a green "P".

Braking function is only transferred from ESP to the electronic parking brake if the "green P" in the instrument cluster is visible and if

  1. The solenoid valves in ESP have reached a temperature of 200° C.
  2. The driver door is opened.
  3. The driver seat belt is unlatched.
  4. The engine is stopped.
  5. The ignition is switched off.
  6. The switch is operated.
  7. The brake pedal or gas pedal are pressed.
  8. The Audi Hold Assist switch is operated without pressing the brake.

Note. When braking function is transferred from the ESP to the electronic parking brake, the instrument cluster display changes from a "green P" to a "red P".

Scheme 24

Scheme 24: ABS HYDRAULIC UNIT -N55- WITH ABS CONTROL MODULE -J104- OVERVIEW
  1. ABS Hydraulic Unit -- with ABS Control Module -- Component location: in the left of the engine compartment. Removing and Installing, refer to «ABS HYDRAULIC UNIT -N55- WITH ABS CONTROL MODULE -J104»(/audi/a5/i-2007-2011/remont/anti-locktraction-control/#anti-lock-brake-system-coupe__abs-hydraulic-unit-n55-with-abs) . The hydraulic control unit is comprised of the ABS hydraulic unit N55 with integrated brake pressure sensor G201 and the ABS control module J104. The components must not be separated from each other. Do not disconnect the connector before successfully completing OBD. Switch the ignition off before disconnecting the connector. The brake pressure sensor G201 is integrated into the ABS hydraulic unit N55 and cannot be replaced. CAUTION: The ABS hydraulic unit N55 and ABS control module J104 must not be separated from each other.
  2. ESP Bracket The bracket cannot be removed.
  3. ABS Control Module -- Electrical Connector
  4. Brake Line To the brake master cylinder. 14 Nm
  5. Brake Line To the brake master cylinder. 14 Nm
  6. Brake Lines Hydraulic unit to right front brake caliper. 14 Nm Hydraulic unit to front left brake caliper. 14 Nm Hydraulic control unit to rear left brake caliper. 14 Nm Hydraulic control unit to rear right brake caliper. 14 Nm

FASTENER TIGHTENING SPECIFICATIONS

ComponentFastener SizeNm
Brake line to hydraulic unit
5 mm diameter M10 brake line12
5 mm diameter M12 brake line12
8 mm diameter M12 brake line16
Electronic stabilization sensor to floor panel nut9
Front wheel speed sensor bolt9
Rear wheel speed sensor bolt8

ABS HYDRAULIC UNIT -N55- WITH ABS CONTROL MODULE -J104

The ABS hydraulic unit N55 with ABS control module J104 is located in the left front of the engine compartment.

Special tools and workshop equipment required

  1. Brake Pedal Actuator V.A.G 1869/2
  2. Repair Kit Plugs 1H0 698 311 A
CAUTIONThe ABS control module J104 and ABS hydraulic unit must not be separated.

REMOVING

Read the control module version and make a note of it.

Note. Use the vehicle diagnostic tester VAS 5051B or VAS 5052 for this.

Disconnect the battery, refer to Removal and Installation , noting the radio code.

Insert the V.A.G 1869/2 between the brake pedal and driver seat by pressing the brake pedal down at least 60 mm. By doing this, the valves in the brake master cylinder are closed and the brake fluid reservoir does not run empty.

Scheme 25

Scheme 25: REMOVING

Connect the hose from a bleeder bottle to the bleeder screw on the left front caliper.

Connect the hose from a bleeder bottle to the bleeder screw on the left front caliper.

Open the bleeder screws on the left front and rear brake calipers to reduce the pressure in the ABS hydraulic unit.

Close the left front and left rear bleeder screws.

Note. Do not remove V.A.G 1869/2.

Press the securing clip on the connector to the control module -1- up.

Scheme 26

Scheme 26

Pull the securing bracket in the -direction of the arrow- and remove the connector.

Scheme 27

Scheme 27

Note. Make sure that no brake fluid enters control module connector housing. This could lead to corrosion of the contacts and thereby cause the system to fail. A contaminated connector housing must be carefully cleaned with compressed air.

To protect against escaping brake fluid, place a lint-free cloth in the area under the control module J104 and hydraulic unit.

Mark the brake lines for installation later.

WARNINGDo not bend or kink the brake lines.

Remove the brake lines from the ABS hydraulic unit and brake master cylinder.

Remove the remaining brake lines -arrows- from the ABS hydraulic unit.

Seal brake lines and threaded holes with plugs from repair kit.

Carefully remove the ABS hydraulic unit together with the ABS control module -- upward from the bracket.

Note. When removing the ESP control unit from the bracket, make sure the rubber buffers do not fall into the engine compartment.

WARNINGExcessive shaking (for example dropping, impact) may destroy the control module. Control module must then no longer be used.

Set the ABS hydraulic unit -- with ABS control module -- down on a clean, level surface.

Note. Seal the threaded holes and brake lines with plugs after removing the ABS control module -- and ABS hydraulic unit --.

WARNINGThe hydraulic pump must not be separated from the hydraulic unit N55.

INSTALLING

Installation is the reverse of removal, with special attention to the following

Note. For customer service, the hydraulic unit N55 is filled with brake fluid. Remove the sealing plugs on the new hydraulic unit N55 when the corresponding brake line is going to be installed. If the sealing plugs are removed from the hydraulic unit N55 before installing the corresponding brake line, the brake fluid will drain. If that is the case, sufficient brake system bleeding can no longer be ensured.

Note. All the rubber buffers must be inserted in the bracket.

Press the hydraulic unit with the ABS control module down into the bracket in the vehicle.

Note. When pressing the ESP control unit into the bracket, counterhold the rubber buffers so they do not fall through.

Connect the brake lines according to the markings.

WARNINGIf the brake line connectors are replaced, an ABS/ESP system malfunction will register.

Note. By performing the output check diagnosis, it can be determined if the line connections were interchanged.

Tighten all the brake lines -arrow- on the ABS hydraulic unit --.

ComponentNm
All brake lines to the hydraulic unit14

Connect the electrical connector on the ABS control module.

Press the locking bracket down until it engages audibly.

Press the securing clip -1- down and engage it.

Remove the V.A.G 1869/2.

Bleed the brake system, refer to BRAKE SYSTEM, BLEEDING .

After securing the brake lines on the hydraulic unit, perform output diagnostic test mode.

Note. By performing the output check diagnosis, it can be determined if the line connections were interchanged.

Use the vehicle diagnostic tester VAS 5051B or 5052 for this.

If ABS hydraulic unit -- was replaced, it must be coded.

Use the vehicle diagnostic tester VAS 5051B or 5052 for this.

On display, select

  1. Chassis
  2. Brake System
  3. 001 - OBD-capable systems
  4. 003- Brake electronics.

Select the following functions on the display

  1. ABS/ASR/ESP control module J104
  2. ABS/ASR/ESP control module J104, functions
  3. J104 Coding control module

The Following Sensors Should Also be Calibrated After Replacing ABS control module.

  1. Steering Angle Sensor G85
  2. Transverse Acceleration Sensor G200
  3. Longitudinal Acceleration Sensor G251

Use the vehicle diagnostic tester VAS 5051B or 5052 for this.

On display, select

  1. Chassis
  2. Brake System
  3. 001 - OBD-capable systems
  4. 003- Brake electronics.

Select the following functions on the display

  1. ABS/ASR/ESP control module.
  2. ABS/ASR/ESP control module functions.

Then perform the ESP driving and system test.

Remove the center console, refer to Removal and Installation .

Remove the Audi Hold Assist switch -2-, refer to "Center Console Lamps and Switches" in Electromechanical Parking Brake Button E538 and -AUTO HOLD- Button E540 .

Installation is performed in reverse sequence.

BRAKE LAMP SENSOR

Special tools and workshop equipment required

  1. Release Tool for Brake Light Switch T40168

Note. After removing, the brake lamp sensor can be re-used. The brake light sensor programs itself. It is not necessary to calibrate it after installation.

Remove the driver side storage compartment -1 to 3-.

Scheme 28

Scheme 28: REMOVING

Disconnect the connector -C- for the footwell vent.

Scheme 29

Scheme 29

Remove the footwell vents -A-B-.

Disconnect the electrical connector to the brake light sensor.

The stop -17- on the brake pedal is an assembly aid during production and does not need to be installed again.

Scheme 30

Scheme 30

Press the brake light sensor plunger -10- all the way in using a finger.

With the plunger pressed in, rotate the colored piece on the brake light sensor left as far as the stop to release the switch.

Note. The plunger must remained pressed in when releasing the brake light sensor.

Let go of the brake light sensor plunger after releasing.

Insert a T40168 between the brake light sensor plunger and the brake pedal.

Note. The cone on the tool must face in the direction of the driver seat. The opening on the tool must align with the bulge on the brake light sensor.

Press the T40168 against the brake lamp sensor. This releases the three retaining tabs on the brake lamp sensor.

Remove the brake lamp sensor from the mount.

The stop -17- on the brake pedal is an assembly aid during production and does not need to be installed again.

Note. The plunger adjusts itself automatically when inserting the brake lamp sensor. The brake pedal must remain in end position during installation and must not be moved. The brake pedal must be connected with the brake booster.

Insert the brake lamp sensor in the mount on the brake pedal and press it in lightly.

Note. The brake lamp sensor must engage audibly with all three retaining tabs. The switch must not be rotated in the mount on the brake pedal. The plunger adjusts itself automatically when inserting the brake lamp sensor.

Rotate the colored piece on the brake lamp sensor to the right as far as the stop to secure the switch.

Connect the electrical connector.

Install the footwell vents -A-B-.

Connect the connector -C- for the footwell vent.

Install the driver side storage compartment -1 to 3-.

Note. Check the brake lamp sensor function after installing it and before driving.

ELECTRONIC STABILIZATION PROGRAM BRACKET

The bracket for the ABS hydraulic unit -N55- with ABS control module -J104- cannot be removed.

ESP SENSOR UNIT -G419

WARNINGThe ESP sensor unit is susceptible to strong vibrations and impacts. Strong vibrations and impacts can damage the ESP sensor unit. If the ESP sensor unit has fallen on the floor, correct function is no longer ensured and the unit should not be installed.

The ESP sensor unit -- is installed under the left seat on all models.

Special tools and workshop equipment required

  1. Torque Wrench V.A.G 1410

The ESP sensor unit -- is installed under the left seat.

The arrow on the ESP sensor unit -- points in the direction of travel.

Remove the left seat, refer to Removal and Installation .

Fold the bar on the carpet up.

On vehicles where the bar on the carpet is not cut through, cut through it using a sharp knife.

Remove the footwell vent.

Disconnect the connector -2-.

Scheme 31

Scheme 31: REMOVING

Remove the sensor unit nuts.

Remove the ESP sensor unit -- -1- upward out of the vehicle.

Note. The arrow on the sensor unit points in the direction of travel.

WARNINGStrong vibrations can destroy the ESP Sensor Unit --.

Insert the ESP sensor unit -- -1- into the mounts from above.

When installing ESP sensor unit --, be sure it is properly seated on the bracket and is free of tension.

Install and tighten the sensor unit nuts.

Connect the electrical connector -2-.

Install the footwell vent.

Fold the bar on the carpet down.

Install the left seat, refer to Removal and Installation .

After Replacing the ESP Sensor Unit --, Perform a Basic Setting (Calibration) on the Following Sensors.

  1. Transverse Acceleration Sensor -G200
  2. Longitudinal Acceleration Sensor -G251

Use the Vehicle Diagnosis, Testing and Information VAS 5051B or VAS 5052 for this.

On display, select

  1. Chassis
  2. Brake System
  3. 001 - OBD-capable systems
  4. 003- Brake electronics

Select the following functions on the display

  1. Calibrate the transverse acceleration sensor G200.
  2. Calibrate the longitudinal acceleration sensor G251.

Then perform the ESP driving and system test.

Remove the center console, refer to Removal and Installation .

Remove the parking brake switch -- -1-, refer to "Center Console Lamps and Switches" in Electromechanical Parking Brake Button E538 and -AUTO HOLD- Button E540 .

The switch is clipped into the front of the center console on the side.

Install in reverse order of removal.

RIGHT FRONT ABS WHEEL SPEED SENSOR -G45- AND LEFT FRONT ABS WHEEL SPEED SENSOR -G47

Right front illustration

Scheme 32

Scheme 32: RIGHT FRONT ABS WHEEL SPEED SENSOR -G45- AND LEFT FRONT ABS WHEEL SPEED SENSOR -G47
  1. Speed Sensors
  2. Hex Socket Head Bolt 9 Nm

Note. The sensor ring/rotor is installed in the respective wheel bearing unit and cannot be replaced.

Raise the vehicle.

Unlock and disconnect the connector -1- from the speed sensor.

Scheme 33

Scheme 33: REMOVING

Remove the bolt -2-.

Remove speed sensor from wheel bearing housing.

Installation is the reverse of removal, with special attention to the following

Before inserting speed sensor, clean hole inner surface and coat speed sensor all-round with Polycarbamide grease G 000 650.

Turn the steering completely left and right after installation, making sure the speed sensor wiring has sufficient clearance.

Lower the vehicle.

RIGHT REAR ABS WHEEL SPEED SENSOR -G44- AND LEFT REAR ABS WHEEL SPEED SENSOR -G46

Left rear illustration.

  1. Speed Sensors
  2. Hex Socket Head Bolt 8 Nm.

Note. The sensor ring/rotor is installed in the respective wheel bearing unit and cannot be replaced.

Raise the vehicle.

Unlock and disconnect the connector -1- from the speed sensor.

Remove the bolt -2-.

Remove speed sensor from wheel bearing housing.

Installation is the reverse of removal, with special attention to the following

Before inserting speed sensor, clean hole inner surface and coat speed sensor all-round with Polycarbamide grease G 000 650.

Lower the vehicle.

STEERING ANGLE SENSOR -G85

The steering angle sensor -- is installed between the steering wheel and steering column switch.

Set the wheels to the straight ahead position.

Coil connector with slip ring -1-.

Scheme 34

Scheme 34: REMOVING

Remove the airbag unit and steering wheel, refer to Removal and Installation .

Clipped onto the switch for turn signals, high/low beam headlamps and headlamp flasher.

Clipped to the coil ring with slip ring.

WARNINGThe coil ring with slip ring must not be turned when they has been removed.

Remove the steering column switch module Removal and Installation .

Install in reverse order of removal.

Install the airbag unit and steering wheel, refer to Removal and Installation .

Calibrate the steering angle sensor

Use the vehicle diagnostic tester VAS 5051B or VAS 5052 for this.

On the display, select

  1. Chassis
  2. Brake system (Repair group 01;45)
  3. 001 - OBD-capable systems
  4. 003- Brake electronics ABS/ESP

Select desired function on display.

  1. ABS Control Module -J104-, ASR and ESP functions
  2. Steering angle sensor calibration, refer to vehicle diagnostic tester VAS 5051 B or VAS 5052.

Then perform the ESP driving and system test.

SPECIAL TOOLS

Special tools and workshop equipment required

Scheme 35

Scheme 35: SPECIAL TOOLS

Scheme 36

Scheme 36
  1. Brake Pedal Actuator V.A.G 1869/2
  2. Repair Kit Plugs 1H0 698 311 A
  3. Torque Wrench V.A.G 1410