On Board Diagnostic (OBD) - Abs/edl/asr Audi A8 D3

General

This is intended as a practical aid for technicians in the dealership when working on the Audi A8 and dealing with symptoms and malfunctions reported by the customer.

If the malfunction is related to one of the systems with the On Board Diagnostic (OBD) capability covered here, this provides the information necessary for the repair.

Function

The control module of a system with OBD detects malfunctions during vehicle operation and stores them as Diagnostic Trouble Codes (DTCs) in a permanent memory. The DTCs remain intact in the memory if the power supply from the battery is interrupted.

The OBD function relates to the electrical and electronic parts of a system, i.e. it only registers malfunctions which have an effect on the electric signals.

OBD enables malfunctions to be traced quickly and efficiently using the VAG1551 or VAG1552 Scan Tool (ST) or the VAS5051 Tester in the "Rapid data transfer" operating mode 1. To do this, the control module must communicate with the scan tool via the data link.

The Data Link Connector (DLC) is the interface for communication between the control module and the scan tool.

To initiate On Board Diagnostic, connect the scan tool to the DLC and establish the communication link with the control module. See VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD .

When the data link has been established, you can then select the required troubleshooting functions provided. These functions are programmed in the form of fixed diagnostic routines, which are described in the relevant sections of this manual. After first checking the control module version, start the troubleshooting procedure with "Check DTC Memory" function 02. All possible OBD functions, see SELECTING FUNCTIONS .

DTCs which may be stored in DTC memory will be indicated on the scan tool display. The information displayed can then be used in conjunction with the DTC table, which enables you to trace the cause of the malfunction and carry out the necessary repair quickly and efficiently.

The OBD distinguishes between "static" and "sporadic" malfunctions. If a malfunction which has been stored as "static" is no longer present when the ignition is switched on, it is converted to "sporadic."

Sporadic malfunctions are identified as such by "/SP" appearing in the display of the VAG1551 scan tool.

A sporadic malfunction is erased automatically if it no longer occurs after a certain number of driving cycles.

Static malfunctions remain stored in DTC memory until the memory is erased using the VAG1551 scan tool.

If the control module has to be replaced, first read the control module version. This appears in the display of the scan tool together with the coding when communication is established between the control module and the scan tool, see VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD .

VAG1551 Scan Tool (ST), connecting and entering address word

Note. The VAG1551 scan tool can be used instead of the VAS5051 diagnostic tester.

1. Note the test conditions for each scan tool.

1. With the ignition off, connect VAS5051 (or VAG1551 using VAG1551/3 adapter cable) to the Data Link Connector (DLC) under the dash to the left of the steering column.

Indicated on display

Scheme 1

1) Two operating modes are displayed alternately.

Note. If there is no display, test the data link connector terminals. See Scan tool operating instructions and the appropriate wiring diagram. Pressing the "PRINT" button switches the VAG1551 printer on; indicator light in button comes on. Pressing the "HELP" button on the VAG1551 scan tool prints additional operating information.

1. Switch ignition on.
2. Press the "PRINT" button to switch the scan tool printer on.
3. Press button -1- to select "Rapid data transfer."

Indicated on display

Scheme 2

Note. The address word selects the control module that you wish to test using the scan tool. It is made up of two digits, which are listed in the relevant sections of this article.

Example: pressing buttons -0- and -3- selects the "Brake Electronics" address word 03

Indicated on display

Scheme 3

1. Press the -Q- button to confirm input.

Rapid data transfer Scan Tool sends address word 03

Indicated on display after entering address word 03

Note. If a malfunction occurs when establishing communication between the VAG1551 scan tool and the control module, refer to the four displays and instructions that follow.

Scheme 4

Scheme 5

Scheme 6

1. Press the "HELP" button to print a list of possible causes of the malfunction.
2. Test power supply and Ground (GND) connections for ABS control module (w/EDL) -J104-.
3. Test cable connections for data link connector wire-K-.

If displayed

Scheme 7

1. Repair the malfunction.
2. After repairing the malfunction, once again enter "Brake Electronics" address word 03 and press -Q- button to confirm input.

If the data link between the VAG1551 scan tool and the control module is established and works properly, the display will now show the control module identification (X), the system identification (Y), the hardware and software versions (Z), and the dealership number (W).

Scheme 8

Note. The --> button is used for advancing through the program sequence. The various On Board Diagnostic (OBD) systems to be tested are described in more detail in the relevant sections of this Repair Manual. The control module version can only be changed by replacing the control module. See Parts catalog. If the control module identification number does not appear in the display, check the diagnostic wiring.

See appropriate System Wiring Diagrams article.

1. Press --> button.

Indicated on display

Scheme 9

Selecting functions

After establishing the data link, checking the control module version, and pressing the --> button

Indicated on display (function selection, example 02 "Check DTC Memory")

Scheme 10

You can now select one of the functions listed below. Start the troubleshooting procedure using the "Check DTC Memory" function 02.

1. Check Control Module Versions
2. Check DTC Memory
3. Output Diagnostic Test Mode
4. Basic Setting
5. Erase DTC Memory
6. End Output
7. Code Control Module
8. Read Measuring Value Block
9. Read Individual Measuring Value
10. Adaptation
11. Login Procedure

Comprehensive descriptions of how to use the functions "Erase DTC Memory" and "End Output" are found in the next section.

Descriptions of how to use the other functions are found in the relevant sections of this Repair Manual.

When a function has been completed, press the --> button to return to the beginning of the troubleshooting procedure ("Select function XX").

Requirements

1. DTC memory checked

1. Press --> button.

Indicated on display

Scheme 11

1. Press buttons -0- and -5- to select "Erase DTC Memory" function 05.

Indicated on display

Scheme 12

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 13

1. Press --> button.

Indicated on display

Scheme 14

Note. If this is displayed, the check sequence has not been carried out. (Scheme 16) Follow the test sequence exactly, that is first check DTC memory, then erase DTC memory in the same diagnostic cycle.

End Output

Indicated on display

Scheme 15

1. Press buttons -0- and -6- to select "End Output" function 06.

Indicated on display

Scheme 16

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 17

1. Switch ignition off.
2. Disconnect scan tool.

Bus

In electronics, a bus is a system used to transport or distribute data.

CAN

The Controller Area Network (CAN) is a bus system that uses two wires called bus lines. Two bus lines are used to detect malfunctions in the lines. Data is transferred to the connected control modules in series (one after the other) across the bus lines.

These control modules communicate with each other via the CAN-bus.

The DTC table indicates the bus must be checked

1. Using the relevant wiring diagram, determine how many control modules are connected to the CAN-bus.
2. Check that the multiple connectors of the control modules are properly connected.
3. Connect the VAG1551 (or VAG1552) scan tool and press the -0- button twice to select the "Automatic Test Sequence" function 00.
4. Before checking the bus lines, make sure that none of the control modules connected are malfunctioning.

Note. In this context, a malfunction means a malfunction that doesn't directly affect the bus system, but that interrupts the functioning of a system. This could be a malfunctioning sensor, for example. A malfunctioning sensor would mean that the sensor signal could no longer be used for data transfer in the bus system. This type of malfunction indirectly affects the bus system. Communication to the control modules that use the relevant sensor signal is interrupted.

Is there is a malfunction?

1. Repair the malfunction before proceeding.
2. Make a note of the malfunctions and erase the DTC memory in all the control modules, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. Press buttons -0- and -6- to select "End Output" function 06. Press -Q- button to confirm input.
4. Refer to the DTC table in the relevant repair manual for help in fixing malfunctions.

All malfunctions have been repaired

1. If communication to the control modules is still interrupted, check the bus lines.

While checking the bus lines, differentiate between the following two situations

1. Two control modules communicating across a "two-line bus system"
2. Three or more control modules communicating across a "two-line bus system"

Scheme 18

Scheme 19

1. Switch ignition off.
2. Disconnect both control modules.
3. Check the bus lines for an open circuit. See appropriate System Wiring Diagrams article.
4. Check whether there is a short circuit between the bus lines. See appropriate System Wiring Diagrams article.
5. Check the bus lines for a short circuit to B+ or Ground (GND).

If no malfunction is found in the bus lines

1. As a test, replace one of the control modules. Select a control module that will take the least amount of time, and cost the least amount of money to replace.
2. If communication between the control modules across the bus is still interrupted, replace the second control module.

Scheme 20

Three or more control modules are communicating across a "two-line bus system"

1. Analyze the DTCs stored in the memories of the control modules.

Note. This analysis will help you locate the cause of the line malfunction.

Example 1

From the DTCs stored in the control module memories, it is determined that control module not 1 is not communicating with control modules 2 and 3.

Scheme 21

Scheme 22

1. Switch ignition off.
2. Disconnect the control modules connected across the bus lines and check the bus lines for an open circuit. See appropriate System Wiring Diagrams article.
3. If no malfunction is found in the bus lines, replace control module 1.

Example 2

From the DTCs stored in the memories, it is determined that control module 2 is not communicating with control modules 1 and 3.

Scheme 23

Scheme 24

1. Switch ignition off.
2. Disconnect the control modules connected across the bus lines and check the bus lines for an open circuit. See appropriate System Wiring Diagrams article.
3. If no malfunction is found in the bus lines, replace control module 2.

Example 3

Using the DTCs stored in the memories, it is determined that none of the control modules are sending or receiving signals.

Scheme 25

Scheme 26

Scheme 27

1. Switch ignition off.
2. Disconnect the control modules connected across the bus lines and check for a short circuit between the bus lines. See appropriate System Wiring Diagrams article.
3. Check the bus lines for a short circuit to B+ or Ground (GND).
4. If the cause for the DTC "Hardware malfunction" cannot be determined, check whether the DTC is caused by one of the control modules. All control modules that use the CAN-bus are still disconnected. The ignition is switched off.
5. Connect one of the control modules. Connect VAG1551 (or VAG1552) scan tool or VAS5051 tester. Switch ignition on, and erase the DTC memory of the control module you just connected. End scan tool output using the "End Output" function 06. Switch ignition off and then on. Leave ignition on for 10 seconds. Then, check the DTC memory of the control module you just connected. If the DTC "Hardware malfunction" is displayed, replace the control module you just connected. If the DTC "Hardware malfunction" is not displayed, connect the next control module and repeat the procedure.

Reconnecting battery, procedures

After connecting the battery terminals, do the following

1. Enter anti-theft radio code. See Radio Operating Manual.

Basic setting for the up and down power windows function

1. Switch ignition on.
2. Using driver's-side power window switch, raise window to stop. Release switch and again apply switch for approximately 2 seconds.
3. Repeat procedure for passenger side window. Up and down power window function is activated.

Setting the clock

1. The clock is located within the tachometer display. The clock is set using the button next to the bottom of the tachometer.
2. A quick pull on the knob and the clock hands move forward minute by minute. If you pull the knob and hold it, the hands move slowly at first and then faster.

Adaptation of throttle valve control module

1. Perform adaptation of throttle valve control module to Engine Control Module (ECM). Use Function 10, Adaption on scan tool.

Application notes

Information in this section applies to ABS/EDL Bosch 5.0 and ABS/EDL/ASR Bosch 5.0, for FWD, from MY 1994 to MY 1997 and for ABS/EDS Bosch 5.0, for AWD, from MY 1994 to MY 1996.

This ABS system featuring an electronic differential lock, ABS/EDL, was introduced as standard equipment with the launch of the Audi A8. A traction control system (ASR) is also available as an optional extra for FWD vehicles.

Scheme 28

1. The ABS/EDL systems and the ASR are system that affect the safety of the vehicle. Work on these systems must only be carried out by qualified personnel.
2. When the ignition is on and the On Board Diagnostic (OBD) detects a malfunction in the system, the ABS/EDL warning light -K47-, the Traction Control Indicator Light - K86- and the red brake warning light come on. The warning lights are in the instrument cluster. The red brake warning symbol is incorporated in the display of the driver information system. The warning lights for ABS/EDL and ASR are located underneath the display. For further information refer to "Warning light functions", see «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__table-of-warning-light-functions) .
3. If the brake system is not fully functional, but the ABS/EDL warning light -K47- and the red brake warning light do not light up, this means the malfunction must be sought in the conventional braking system (mechanical/hydraulic components).

Road test

1. Certain malfunctions are only detected by the On Board Diagnostic (OBD) when the vehicle is moving. The system can be tested by carrying out a test drive. Maintain a speed above 60km/h for a period of 30 seconds. Observe the traffic conditions and perform a braking controlled by the ABS. The control can be felt by a pulsing sensation at the brake pedal.

If there is a complaint, a pin-pointed troubleshooting must be carried out

1. First switch on the ignition and observe lighting up of the warning lights. «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__table-of-warning-light-functions) enables an initial determination.
2. Determine test preconditions. See «TEST REQUIREMENTS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-requirements) .
3. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
4. Check control module version (see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) ) and press --> button.
5. Check DTC memory (see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) ). If a DTC is stored: Make a note of the DTC and erase DTC memory (see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) ).
6. Complete data transfer with the function "End output". See «CAN-BUS, FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
7. Repair malfunction according to DTC table (see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) ). Reselect "Brake Electronics" with address word 03. Check and erase DTC memory.
8. Complete data transfer with the function "End output". Disconnect V.A.G 1551.
9. Make sure that all connectors are connected correctly. Perform road test, see «ROAD TEST»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__road-test) . The warning lights must not light up during the road test. If the warning lights light up during the road test the troubleshooting must be performed again.

Note. If the connector is disconnected from the control module during the drive there is danger of setting a false DTC entry in the DTC memory of another control module. The mechanical and hydraulic functions of the brake system remain effective. However, due to the failure of the ABS/EDL system the brake pressure regulator will also no longer work, which could endanger the safety of the vehicle when driving.

1. Switch off the ignition before removing and installing components. If the vehicle is equipped with a coded radio, obtain the security code before disconnecting the battery Ground (GND).
2. If a component is indicated as being faulty, only replace it if you are sure that the wiring for that component is in proper condition. The wiring must be able to transmit the necessary signals without interference or resistance. Check the wiring for: Corrosion and loose connections in the plug connectors and Ground (GND) connections. If any of the connector terminals are bent, broken or corroded, use the wiring repair kit VAS 1978 to install new terminals Open circuits Short circuits to Ground (GND) or to positive See appropriate System Wiring Diagrams article. NOTE: The instructions supplied with wiring repair kit VAS 1978 normally do not permit repairs to the wiring of the ABS and its associated systems. However, this only applies to the screened wiring in the systems.
3. If control module has to be replaced make sure the correct version is installed. Check the control module index first. This appears on the display of the Scan tool V.A.G 1551 together with the encoding once communications have been established between control module and Scan tool, or it can be called up by selecting function 01 "Checking control module version". See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) .
4. If the hydraulic control module has to be replaced make sure the correct version is installed. Check the control module version first. This appears on the display of the Scan tool V.A.G 1551 once communications have been established between control module and Scan tool, or it can be called up by selecting function 01 "Checking control module version". See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) . It is also possible to identify the equipment installed on the vehicle from a combination of letters on the vehicle data sticker. The sticker is in the spare wheel well. 1AC: Anti-lock brake system 1AH: Anti-lock brake system with electronic differential lock 1AJ: Anti-lock brake system with electronic differential lock and traction control system (ASR) 1AT: Anti-lock brake system with electronic differential lock, traction control system (ASR) and electronic stability program (ESP)
5. Absolute cleanliness is required when working on the hydraulic unit. Carefully clean the hydraulic connections and adjacent parts. Never use aggressive cleaning agents such as brake cleaner, gasoline, thinner or products containing mineral oil, oils and greases. Do not disconnect hydraulic lines before they have been cleaned.
6. Do not remove bolts securing individual components of the hydraulic unit. This does not apply to the bolt securing the cover. The cover must be detached in order to replace either of the two relays for the return pump or the solenoid valves.
7. Observe the relevant information when handling brake fluid. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
8. Place removed parts on a clean surface and cover. Only use lint-free cloths.
9. Only use genuine wrapped parts. Only remove them from their packaging immediately prior to installation.
10. Bleed the brake system if connections in the system have to be opened. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
11. Welding work with an electric welding unit can affect the ABS, ABS/EDL and ABS/EDL/ASR system.

Test requirements

1. Permissible and identical wheels and tire size Correct tire pressure at all wheels.
2. Mechanical and hydraulic parts of the brake system must be in order: Hydraulic connections and lines are not leaking (visual check of hydraulic unit, brake callipers, wheel brake cylinder, tandem brake master cylinder).
3. Wheel bearings and wheel bearing play OK. See «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) . See «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. Wheel speed sensors must be installed correctly. See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
5. Supply voltage OK (min. 10.5 V).
6. Ground (GND) connection for return pump -V39- on hydraulic unit must be OK.
7. Connector properly attached to ABS Control Module (w/EDL) -J104-, catch engaged.
8. The diagnosis procedure can only be started with the vehicle stationary and the ignition switched on (or with engine running). The diagnosis cannot be started if wheel speed exceeds 1.65 mph (2.75 km/h). Diagnosis is terminated if speed exceeds 12.4 mph (20 km/h).
9. While testing the ABS, ABS/EDL and ASR systems, ensure that the vehicle's electrical devices are not subjected to electromagnetic interference: keep the vehicle away from equipment with a high current draw such as electric welding units.

Technical publications required

1. Applicable electrical wiring diagram See appropriate System Wiring Diagrams article.
2. Locations of electrical components: See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. Brakes, brake mechanics: See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
4. Brakes, brake hydraulics: See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
5. Notes on elimination of current Diagnostic Trouble Codes (DTC)

Function of Bosch ABS 5.0 Series

This Bosch 5.0 series ABS system featuring an electronic differential lock was introduced as standard equipment with the launch of the Audi A8. A traction control system (ASR) is also available as an optional extra for FWD vehicles.

The brake system is split diagonally into two. One supplying the left front and right rear brakes and one supplying the right front and left rear brakes.

Electronic brake force distribution

The ABS Control Module (w/EDL) -J104- is programmed with specially designed software for electronic brake distribution which assumes the function of the brake pressure regulator.

The anti-lock brake system (ABS) prevents the wheels from locking when the brakes are applied by the driver.

The electronic differential lock (EDL) is an aid when driving away from a standstill. An electronically controlled brake application on the spinning driven wheel provides a torque reaction point for the differential. This enables the wheel with better traction to make use of the engine power. This also applies when reversing.

EDL is standard equipment on vehicles with AWD. While EDL acts on all four wheels in vehicle with AWD on vehicles with FWD it acts only on the front wheels. A mechanical differential lock is not required.

The EDL control function can be initiated at road speeds up to 40 km/h.

To stop the brakes overheating the EDL control function is suppressed if the temperature of the brakes exceeds a certain value. The temperature value is defined in ABS Control Module (w/EDL) -J104-. The temperature of the brakes is calculated by the control module using a simulation formula. The EDL is then reactivated if the calculated temperature drops below a predetermined lower threshold. The operation of the conventional brake system and the ABS and ASR traction control functions are not affected by this automatic cut-off feature.

When the brakes are hot, the control module still remains active for up to one hour after the ignition is switched off. It switches itself off when the calculated brake temperature drops below the predetermined threshold. During this time the control module operates with an increased current draw of 500 mA compared to less than 0.5 mA when the control module is not in operation.

The EDL on AWD models manufactured as of 05/95 is actuated via the suction side of the circuit. The pressure which is built up in the brake system to restrain a spinning wheel when the EDL operates is now controlled via the suction side of the ABS return pump, and not via the pressure delivery side, as on previous models. The control process is defined by the control module.

This technology reduces the operating noise during an EDL control cycle.

The pressure dampers that were previously screwed into the hydraulic unit and were used to reduce the operating noise are no longer installed. The working range of the pressure limiting valve in the hydraulic unit is raised from 90 +/-25 bar to 170 +/-25 bar.

ASR (traction control system, is installed only on vehicles with front-wheel drive: In these vehicles observe control module encoding. See ENCODE CONTROL MODULE . The traction control function requires an exchange of signals between ABS Control Module (w/EDL) -J104-, the Engine Control Module (ECM) and the transmission control module. The control modules communicated with each other.

The ASR traction control system prevents the driven wheels from spinning under acceleration: The system operates by reducing engine torque and is active at all speeds. The EDL and ASR functions act together to assist acceleration.

If required, the ASR function can be switched off (and on again) by means of the ASR switch in the center console. The ASR will be reactivated automatically the next time the ignition is switched on. When the system is deactivated the Traction Control Indicator Light lights up in the instrument cluster "Read measured value block". See READ MEASURED VALUE BLOCK . The warning light flashes at a rate of three times per second when the control function starts working.

Table of warning light functions

1. First switch on the ignition and check that the warning lights light up. The status of the ABS Warning Light -K47-, the Traction Control Indicator Light -K86- and the red brake warning light will give you a first indication of the operating status of the system.

The red brake warning light is incorporated in the display of the driver information system.

Scheme 29

The ABS Warning Light -K47-, (-4-), and the Traction Control Indicator Light -K86-, (-12-), are located underneath the display.

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

1. For Electrical check, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__electrical-testing) .
2. For DTC Memory, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) .

Function of On Board Diagnostic (OBD)

On vehicles with ABS/EDL, the On Board Diagnostic (OBD) function can detect 24 different causes of malfunctions. A total of 29 malfunctions can be detected on vehicles additionally equipped with ASR.

Note. The system performs a self test routine when the ignition is switched on before every trip. This process is indicated by the yellow ABS/EDL warning light -K47-. On vehicles with ASR the Traction Control Indicator Light -K86- will also light up. The warning lights will go out after about 2 seconds. The self test routine continues for a short time when the vehicle is moving, as some malfunctions can only be detected above a certain speed. During the self-test process there will be some audible noise from the relays and the return pump in the hydraulic control module, and a slight pulsation at the brake pedal. This is unavoidable, and is not a malfunction which requires correction. If a malfunction is detected by the On Board Diagnostic (OBD) function, the system concerned is switched off automatically for the duration of the current driving "cycle". This is indicated by the relevant warning light in the instrument cluster. For further details refer to section "Warning light functions". See TABLE OF WARNING LIGHT FUNCTIONS . The above does not apply to either of the two DTCs "00526 Brake light switch" and "00668 Vehicle voltage, terminal 30". See CHECK DTC MEMORY . If one of these malfunctions is detected the EDS function is suppressed. None of the warning lights light.

Note. If Scan tool V.A.G 1551 is connected and the diagnostic link has been established with ABS Control Module (w/EDL) -J104-, no control function will be active. The ABS/EDL warning light -K47- and the red brake warning symbol should light up. On vehicles with ASR the Traction Control Indicator Light -K86- will also light up.

Technical data of On Board Diagnostic (OBD)

1. DTC memory Non-erasable memory, contents are retained even after disconnecting supply voltage.
2. Data output Rapid data transfer (mode 1)
3. Functions: OBD FUNCTIONS: BOSCH 5.0 Function No. Function Go to 01- Check control module Version «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) 02- Check DTC memory «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) 05- Erase DTC memory «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 06- End output «CAN-BUS, FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 07- Encode control module «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__encode-control-module) 08- Read measured value block «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__read-measured-value-block)

Check control module version

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03, see «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Go back to the initial settings of the program by pressing the --> button

Indicated on display

Scheme 35

1. Press buttons -0- and -1- for the function "Check control module version" and confirm entry with -Q-button.

Note. The control module version can only be altered by installing a new control module. Also refer to the Parts List for the correct ABS Control Module (w/EDL) -J104- for the vehicle.

Indicated on display

Scheme 36

Code is only shown for vehicles with traction control system (ASR). Encode control module, see ENCODE CONTROL MODULE .

The workshop code, WSC XXXXX, identifies the workshop which performed the last coding of the control module.

1. Control module index
2. System designation
3. Hardware and software status

CONTROL MODULE VERSIONS - 1 OF 2

CONTROL MODULE VERSION - 2 OF 2

Scheme 37

1. Press --> button. Indicated on display

Check DTC memory

1. Determine test preconditions. See «TEST REQUIREMENTS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-requirements) .
2. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
3. Check control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) and press --> button.
4. Press buttons 0 and 2 for "Check DTC memory" function and press -Q- button to confirm entry.

Note. Each malfunction is assigned a 5-digit DTC. It is listed in the left-hand column of the DTC table. The message identifying the malfunction and the DTC will be printed out on the printer of Scan tool V.A.G 1551 if the Print button is pressed. The DTC does not appear on the display of V.A.G 1551. The content of the DTC memory is retained until it is erased. See ERASE DTC MEMORY . Sporadic DTCs (see FUNCTION ) are additionally identified as such with "/SP" appearing on the right of the display. Static malfunctions which cannot be detected when the vehicle is stationary are also identified with "/SP" after the ignition has been switched off and then on again.

Scheme 38

Scheme 39

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Scheme 51

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Scheme 58

Scheme 59

1. The following table includes all the DTCs which can be detected by the ABS Control Module (w/EDL) -J104- and displayed and printed out by V.A.G 1551. Malfunctions are listed according to DTCs.

1. For "Warning light functions", see «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__table-of-warning-light-functions) .
2. For "Electrical check", see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__electrical-testing) .
3. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
4. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front)
5. For speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
6. For read measured value block (Display Group 1), see «TEST TABLE, DISPLAY GROUP 1»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-table-display-group-1) .
7. For read measured value block (Display Group 2), see «TEST TABLE, DISPLAY GROUP 2»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-table-display-group-2) .
8. For read measured value block (Display Group 3), see «TEST TABLE, DISPLAY GROUP 3»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-table-display-group-3) .
9. For control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) .
10. For ABS Control Module (w/EDL) encoding info, see «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__encode-control-module) .

Encode control module

If a control module with traction control function (ASR) is replaced, or if the following malfunction is stored in the DTC memory of the control module.

1. "ABS/EDL/transmission - electrical connection"

The control module must be coded according to the type of engine and transmission.

Note. The coding can only be performed if a workshop code is stored in V.A.G 1551 See Operating instructions for V.A.G 1551 The 5-digit coding will appear when the control module identification is displayed. The ABS/EDL/ASR control module with index "N" was additionally introduced as of 05.95 together with automatic transmission 01V for vehicles with ASR traction control. Alternative control module codes for automatic transmission 01V were added accordingly. Control modules with index "N" supplied as replacement parts can be used to replace previous control modules with index "M". Control modules with index "M" will no longer be supplied as replacement parts for vehicles prior to 05.95 once existing stocks have been used up.

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Check control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) . Press --> button.

Note. A 3-digit or 5-digit code must always be displayed. The control module must be coded as follows if the display does not show the correct code for the vehicle or if a new control module has been installed.

Indicated on display

Scheme 60

1. Press buttons -0- and -7- for "Coding control module" function.

Indicated on display

Scheme 61

1. Confirm input with -Q- button.

Indicated on display

Scheme 62

1. Enter the required code number and confirm with -Q- button.

CONTROL MODULE CODE NUMBER - BOSCH 5.0

Scheme 63

Scheme 64

The display shows the control module identification and the code entered (For example, 00000). (Scheme 67)

Scheme 65

1. Press --> button.

Indicated on display

Scheme 66

1. Press buttons -0- and -6- for the "End output" function and press the -Q- button to confirm entry.

Read measured value block

The control module can transfer measured values to the Scan tool V.A.G 1551. This test data delivers information about the condition of the system and the sensors connected. In many cases the transferred test data can be used to support the troubleshooting and remedy. The measured values available from the Bosch type 5.0 system are grouped in three display groups, which can be called up via display group numbers.

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . NOTE: When the printer is switched on, the contents of the display will be printed out on the Scan tool log. When "Read measured value block", also check wiring and connectors for loose connections.
2. Check the control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-control-module-version) and press the --> button.

Indicated on display

Scheme 67

1. Press buttons -0- and -8- for "Read measured value block" function.

Indicated on display

Scheme 68

1. Confirm input with -Q- button.

Indicated on display

Scheme 69

1. Press buttons -0-, -0- and -1-.
2. Confirm input with -Q- button.

Test table, Display group 1

Note. The display zones 1 to 4 show the actual wheel speeds at the tire circumference in km/h. These are calculated by ABS Control Module (w/EDL) -J104- on the basis of the pulses received from the wheel speed sensors. If one of the display zones shows no reading, proceed as for DTCs 00283, 00285, 00287, 00290 "Speed sensor". See CHECK DTC MEMORY . In order to check that the speed sensor signals are correctly assigned to the four wheels, the vehicle must be raised. On vehicles with manual transmission put the gear lever in neutral. On vehicles with automatic transmission move the selector lever to position "N". Turn appropriate wheel by hand. The other wheels must be prevented from rotating. When the vehicle is accelerated uniformly on a dry surface, the displayed values will increase continuously in rising whole numbers, e.g.... 6 km/h, 7 km/h, 8 km/h.... The difference between displayed values 1 to 4 should be no more than +/- 1 km/h (rounding errors). If the values jump, for instance from... 6km/h, 7km/h, to 12 km/h... or if the difference between the displayed values is greater than +/- 1 km/h then check the installation of the wheel speed sensors and rotors.

See SUSPENSION - FRONT .

See SUSPENSION - REAR .

Scheme 70

1) ABS Control Module (w/EDL) -J104- terminates On Board Diagnostic (OBD) if speed exceeds 19 km/h.

By pressing the buttons <-1 and 3-> the display group numbers may be selected consecutively.

1. Press button -C- in order to enter the display group number manually.

Indicated on display

Scheme 71

1. Press buttons -0-, -0- and -2-.
2. Confirm input with -Q- button.

Scheme 72

1. For "Electrical check", see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__electrical-testing) .

By pressing the buttons <-1 and 3-> the display group numbers may be selected consecutively.

1. Press button -C- in order to enter the display group number manually.

Indicated on display

Scheme 73

Note for display group 3

If display zones for engine speed and actual engine torque are to be read out with engine running communication between Scan tool and control module must be terminated with "End output" function, see END OUTPUT . Then start engine and set up diagnostic link between Scan tool and control module again.

1. Press buttons -0- and -8- for "Read measured value block" function.
2. Confirm input with -Q- button.
3. Press buttons -0-, -0- and -3-.
4. Confirm input with -Q- button.

Test table, Display group 3

1. For "Electrical check", see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__electrical-testing) .
2. For DTC Table, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__dtc-table) .

Scheme 74

Electrical testing

1. For vehicles for which the self - diagnosis does not give any indication of the source of the malfunction the complete electrical check must be worked through.
2. In vehicles in which the self- diagnosis provides a direct indication of the source of the malfunction only perform the test steps recommended in the DTC table (specific testing).

1. An "Automatic test sequence" must first be performed to establish that any DTCs present in the transmission and Engine Control Module (ECM)s can only originate from the ABS. Connect up Scan tool V.A.G 1551 and select address word 00 with ignition switched on. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . After completing the "Electrical check", check and erase the DTC memories of the transmission and Engine Control Module (ECM)s.
2. Make sure multiple connector between wiring harness and ABS Control Module (w/EDL) -J104- is in perfect condition, i.e. not bent, broken or corroded terminals. Replace any damaged terminals using wiring repair kit VAS 1978.

Note. The instructions supplied with wiring repair kit VAS 1978 normally do not permit repairs to the wiring of the ABS and its associated systems. However, this only applies to the screened wiring in the systems.

Scheme 75

1. Switch ignition and electrical devices off before beginning the check (headlights, lighting, fan, etc.).
2. For test steps 13 to 16 the vehicle must be raised so that the wheels can turn freely. On vehicles with manual transmission put the shift lever in neutral. On vehicles with automatic transmission move the selector lever to position "N".

The following equipment is required

1. VAG 1598/20 Test box
2. VAG 1594 Adapter cable set
3. VAG 1526 Hand-held multimeter
4. VAG 1310 A Pressure gauge

Connecting test box VAG 1598/20 and checking ABS/EDL and ASR systems.

Scheme 76

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Scheme 81

1. Switch ignition off.
2. Remove ABS Control Module (w/EDL) -J104- See «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. Disconnect the multi-pin connector from ABS Control Module (w/EDL) -J104-.
4. Check multi-pin connector between wiring harness and ABS Control Module (w/EDL) -J104-. Socket designations of test box VAG 1598/20 are identical with terminal designations on ABS Control Module (w/EDL) -J104- as well as those on wiring harness connector. See appropriate System Wiring Diagrams article.
5. Connect test box VAG 1598/20 to multi-pin connector on ABS harness.

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Scheme 102

1. The terminal descriptions of test box VAG 1598 are identical to the terminal descriptions of ABS Control Module (w/EDL) -J104- in the wiring diagram. Incorrect test procedures can cause system damage. Do not make connections between any terminals other than those listed in the test table. See appropriate System Wiring Diagrams article.
2. The specified values refer to the readings obtained on tester VAG 1526 and are not necessarily applicable to other test units.
3. If the readings obtained do not match the specified values, carry out the DTC correction measures in the right-hand part of the table. See appropriate System Wiring Diagrams article.
4. If the specified values are achieved, also check wiring for loose connections and short circuit to positive and Ground (GND). This applies especially to sporadic DTCs.
5. Use test leads VAG 1594 for checking continuity (bridging leads).
6. If the measured figures only differ slightly from the specified values, clean the terminals of the testers and test leads (with terminal spray G 000 700 04) and repeat the check. Before replacing components, check wiring and connections again. This is particularly important if the specification calls for a resistance reading of less than 10 ohm.. The output connections on ABS Control Module (w/EDL) -J104- are wired differently for the various different versions. 1) FWD with Bosch ABS/EDL 5 only 2) FWD with Bosch ABS/ASR 5 only 3) 4WD with Bosch ABS/EDL 5 only (pressure-side control) 4) 4WD with Bosch ABS/EDL 5 only (suction-side control) For the DTC Table, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__dtc-table) . For brake bleeding instructions, see «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) . For ABS Hydraulic Unit info, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) . For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03). For speed sensor circuit information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) . For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03). For information about connecting V.A.G. 1551, see «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . To check DTC memory, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) . To erase DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03).

Information in this section applies to ABS/EDL Bosch 5.3 for AWD vehicles from MY 1997 and for ABS/EDL/ASR Bosch 5.3 for FWD vehicles from MY 1998.

Bosch ABS/EDL 5.3 was introduced for the Audi A8 from MY 1997 on AWD vehicles. The new version supersedes the Bosch type 5.0.

Bosch ABS/EDL/ASR 5.3 was introduced for the Audi A8 from MY 1998 as an optional extra on FWD vehicles. The new version supersedes the Bosch type 5.0.

The Bosch type 5.3 system has a more compact design. The ABS Return Flow Pump -V39-, the ABS Hydraulic Unit -N55- and the ABS Control Module (w/EDL) -J104- are combined to form the Hydraulic Control Module -N174-. The bolts that connect the individual components of the ABS Hydraulic Unit must not be loosened.

Scheme 103

1. The ABS/EDL systems and the ASR are system that affect the safety of the vehicle. Work on these systems must only be carried out by qualified personnel.
2. When the ignition is on and the On Board Diagnostic (OBD) detects a malfunction in the system, the ABS Warning Light -K47-, the Traction Control Indicator Light -K86- and the red brake warning light come on. The warning lights are located in the instrument cluster. The red brake warning light is incorporated in the display of the driver information system. The warning lights for ABS/EDL and ASR are located underneath the display. For further information refer to "Warning light functions". See «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. If the brake system is not fully functional, but the ABS Warning Light -K47- and the red brake warning light do not light up, this means the malfunction must be sought in the conventional braking system (mechanical/hydraulic components). See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .

1. Certain DTCs are only detected by the On Board Diagnostic (OBD) when the vehicle is moving. The system can be tested by carrying out a test drive. Maintain a speed above 60 km/h for a period of 30 seconds. Observe the traffic conditions and perform a braking controlled by the ABS. The control can be felt by a pulsing sensation at the brake pedal. WARNING: If the vehicle is driven after a malfunction has been detected there is danger of an accident! The function of the brake system will be impaired. As the brake pressure is no longer controlled by the electronic brake force distribution the rear wheels tend to break excessively. Due to this the tail of the vehicle may break away unexpectedly. If test and measuring instruments are required during a test drive, these must always be secured to the rear seat and operated by a second person from this position. If test equipment were operated from the front passenger seat, the person sitting there could be injured if the front passenger airbag were triggered in the event of an accident. If there is a complaint a pin-pointed troubleshooting must be carried out: First switch on the ignition and observe lighting up of the warning lights. The «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) enables an initial determination. Determine test preconditions. See «TEST REQUIREMENTS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . Check control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) and press --> button. Check DTC memory. See «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . If a DTC is stored: Make a note of the DTC and erase DTC memory. See «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . Complete data transfer with the function "End output". See «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) . Repair malfunction according to DTC table, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . Reselect "Brake Electronics" with address word 03. Check and erase DTC memory. Complete data transfer with the function "End output". Disconnect Scan tool V.A.G 1551. Make sure that all connectors are connected tightly and correctly. Perform test drive. See «ROAD TEST»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . The warning lights must not light up during the test drive. If the warning lights light up during the test drive the troubleshooting must be carried out again. NOTE: If the connector is disconnected from the control module during the road test, there is danger of a false DTC entry into the DTC memory of another control module. The mechanical and hydraulic functions of the brake system remain effective. However, due to the failure of the ABS/EDL system, the brake pressure regulator will also no longer work, which could endanger the safety of the vehicle when driving.
2. Switch off the ignition before removing and installing components. If the vehicle is equipped with a coded radio, obtain the security code before disconnecting the grounding strap of the battery.
3. If a component is indicated as being faulty, only replace it if you are sure that the electrical wiring for that component is in proper condition. The wiring must be able to transmit the necessary signals without interference or resistance. Check the wiring for: Corrosion and loose connections in the connectors and Ground (GND) connections. If any of the connector terminals are bent, broken or corroded, use the wiring repair kit VAS 1978 to install new terminals. Open circuits Short circuits to Ground (GND) or to positive NOTE: The instructions supplied with wiring repair kit VAS 1978 normally do not permit repairs to the wiring of the ABS and its associated systems. However, this only applies to the screened wiring in the systems.
4. If the hydraulic control module has to be replaced make sure the correct version is installed. Check control module version first. This appears on the display of the Scan tool V.A.G 1551 once communications have been established between control module and Scan tool, or it can be called up by selecting function 01 "Checking control module version". See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . It is also possible to identify the equipment installed on the vehicle from a combination of letters on the vehicle data sticker. The sticker is located in the spare wheel well. 1AC: Anti-lock brake system 1AH: Anti-lock brake system with electronic differential lock 1AJ: Anti-lock brake system with electronic differential lock and traction control system (ASR) 1AT: Anti-lock brake system with electronic differential lock, traction control system (ASR) and electronic stability program (ESP)
5. Absolute cleanliness is required when working on the hydraulic control module. Carefully clean the hydraulic connections and adjacent parts. Never use aggressive cleaning agents such as brake cleaner, gasoline, thinner or products containing mineral oil, e.g. oils and greases. Do not disconnect hydraulic lines before they have been cleaned.
6. Observe the relevant information when handling brake fluid. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
7. Place removed parts on a clean surface and cover. Only use lint-free cloths.
8. Only use genuine wrapped parts. Only remove them from their packaging immediately prior to installation.
9. Bleed the brake system if connections in the system have to be opened. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .

1. Permissible and identical wheels and tire size Correct tire pressure at all wheels.
2. Mechanical and hydraulic parts of the brake system must be in order: Hydraulic connections and lines are not leaking (visual check of ABS Hydraulic Unit, brake callipers, wheel brake cylinder, tandem brake master cylinder).
3. Wheel bearings and wheel bearing play OK. See «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) . See «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. Wheel speed sensors must be installed correctly. See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
5. Supply voltage OK (at least 10.0 V).
6. Connector properly attached to ABS Control Module (w/EDL) -J104-, catch engaged.
7. The diagnosis procedure can only be started with the vehicle stationary and the ignition switched on (or with engine running). The diagnosis cannot be started if wheel speed exceeds 2.75 km/h. Diagnosis is terminated if speed exceeds 20 km/h.
8. While testing the ABS, ABS/EDL and ASR systems, ensure that the vehicle's electronics are not subjected to electromagnetic interference: keep the vehicle away from equipment with a high current draw such as electric welding units.

Function of Bosch ABS 5.3 Series

The Bosch type 5.3 system has a more compact design. The ABS Return Flow Pump -V39-, the ABS Hydraulic Unit - N55- and the ABS Control Module (w/EDL) -J104- are combined to form the hydraulic control module. The bolts that connect the individual components of the ABS Hydraulic Unit -N55-must not be loosened.

The direct connection between these components reduces possible sources of DTCs. There is no provision for repairing the hydraulic control module - it must be replaced if faulty.

The brake system is split diagonally into two. One supplying the left front and right rear brakes and one supplying the right front and left rear brakes.

The ABS Control Module (w/EDL) -J104- is programmed with specially designed software for electronic brake force distribution which assumes the function of the brake pressure regulator.

The anti-lock brake system (ABS) prevents the wheels from locking when the brakes are applied by the driver.

The electronic differential lock (EDL) is an aid when driving away from a standstill. An electronically controlled brake application on the spinning driven wheel provides a torque reaction point for the differential. This enables the wheel with better traction to make use of the engine power. This also applies when reversing.

EDL is standard equipment on vehicles with AWD. While EDL acts on all four wheels in vehicle with AWD on vehicles with FWD it acts only on the front wheels. A mechanical differential lock is not required.

The EDL control function can be initiated at road speeds up to 40 km/h. Once EDL has been activated it cuts out automatically at a predetermined upper speed threshold of 40 km/h on vehicles with FWD and 80 km/h on vehicles with all wheel drive.

Suction dampers are screwed into the ABS Hydraulic Unit. They assist the build-up of pressure in the corresponding wheel brake cylinders when EDL is active. The operating range of the pressure limiting valve in the ABS Hydraulic Unit is 170 + 25 bar.

To stop the brakes overheating the EDL control function is suppressed if the temperature of the brakes exceeds a certain value. The temperature value is defined in ABS Control Module (w/EDL) -J104-. The temperature of the brakes is calculated by the control module using a simulation formula. The EDL is then reactivated if the calculated temperature drops below a predetermined lower threshold. The operation of the brake system and the ABS function are not affected by this automatic cut-off feature.

When the ignition is switched off, the calculated temperature of the hot brakes is stored in the memory until the ignition is switched on again. When the ignition is switched on, the instrument cluster sends a time signal which enables the ABS Control Module (w/EDL) -J104- to calculate the period the vehicle has been left standing. This period is put into the temperature simulation formula to calculate the new temperature of the brakes. If the vehicle has been left standing for more than one hour, the control module will automatically assume a brake temperature equal to the lowest value in the simulation formula.

If EDL is deactivated on account of the temperature limit being exceeded, this is indicated in the measured value block for a period of 20 ignition cycles. See READ MEASURED VALUE BLOCK .

ASR (traction control system is installed only on vehicles with front-wheel drive: In these vehicles observe control module encoding. See ENCODE CONTROL MODULE . The traction control function requires an exchange of signals between ABS Control Module (w/EDL) -J104-, the Engine Control Module (ECM) and the transmission control module. The control modules communicated with each other.

Two communications systems are in use

1. Data transfer takes place on several individual wires.
2. Data are transferred by way of the CAN-bus. See «CAN-BUS, FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . The CAN-bus employs only two wires These are capable of transmitting all the necessary data.

To find out which communications system is being used for data transfer, check the control module version (see CHECK CONTROL MODULE VERSION ) and read out the table of control module versions (see CHECK CONTROL MODULE VERSION ).

The ASR traction control system prevents the driven wheels from spinning under acceleration: The system operates by reducing engine torque and is active at all speeds. The EDL and ASR functions act together to assist acceleration.

Depending on the engine version, the ASR also incorporates an overrun torque limiting function (MSR). MSR prevents the driven wheels from locking up due to excessive engine braking torque, for instance when the driver changes down from 3rd to 2nd gear. The engine braking effect is reduced via the idle volume control.

If required, the ASR function can be switched off (and on again) by means of the ASR switch in the center console. The ASR switch has no influence on MSR. The ASR will be reactivated automatically the next time the ignition is switched on. When the system is deactivated the Traction Control Indicator Light lights up in the instrument cluster "Read measured value block". See READ MEASURED VALUE BLOCK . The warning light flashes at rate of three times per second when the control function starts working.

1. First switch on the ignition and check that the warning lights light up. The status of the ABS Warning Light -K47-, the Traction Control Indicator Light -K86- and the red brake warning light will give you a first indication of the operating status of the system.

The red brake warning light is incorporated in the display of the driver information system.

Scheme 104

The ABS Warning Light -K47-, (-4-), and the Traction Control Indicator Light -K86-, (-12-), are located underneath the display.

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

1. For information about performing an "Electrical check", see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03).
3. To check DTC memory, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. For reading of the measured value block, see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

On vehicles with ABS/EDL, the On Board Diagnostic (OBD) function can detect 14 different causes of DTCs. A total of 23 DTCs can be detected on vehicles additionally equipped with ASR

Note. The system performs a self test routine when the ignition is switched on before every trip. This process is indicated by the yellow ABS Warning Light -K47- On vehicles with ASR the Traction Control Indicator Light -K86- will also light up. The warning lights will go out after about 2 seconds. The self test routine continues for a short time when the vehicle is moving, as some DTCs can only be detected above a certain speed. During the self-test process there will be some audible noise from the relays and the return pump in the hydraulic control module, and a slight pulsation at the brake pedal. This is unavoidable, and is not a malfunction which requires immediate correction. If a malfunction is detected by the On Board Diagnostic (OBD) function, the system concerned is switched off automatically for the duration of the current driving "cycle". This is indicated by the relevant warning light in the instrument cluster. For further details refer to section "Warning light functions". See TABLE OF WARNING LIGHT FUNCTIONS . The above does not apply to either of the two DTCs "00526: Brake light switch" or "01203: ABS/instrument cluster electrical device" DTC table. See CHECK DTC MEMORY onward. If one of these DTCs is detected, none of the warning lights will light up. These DTCs only affect the operation of the EDL.

Note. If Scan Tool V.A.G 1551 is connected and the diagnostic link has been established with ABS Control Module (w/EDL) -J104-, no control function will be active. The ABS Warning Light -K47- and the red brake warning light should light up. On vehicles with traction control (ASR) the Traction Control Indicator Light -K86- will also light up.

1. DTC memory Non-erasable memory, contents are retained even after disconnecting supply voltage.
2. Data output Rapid data transfer (mode 1)
3. Functions: OBD FUNCTIONS - BOSCH 5.3 Function No. Function Go to 01- Check control module version «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 02- Check DTC memory «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 03- Output Diagnostic Test Mode (DTM) «OUTPUT DIAGNOSTIC TEST MODE (DTM)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__output-diagnostic-test-mode-dtm) 05- Erase DTC memory «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 06- End output «CAN-BUS, FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 07- Encode control module «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) 08- Read measured value block «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Go back to the initial settings of the program by pressing the --> button

Indicated on display

Scheme 111

1. Press buttons -0- and -1- for the function "Check control module version" and confirm entry with -Q- button. NOTE: The control module version can only be altered by installing a new control module. Also refer to the Parts List for the correct ABS Control Module (w/EDL) -J104- for the vehicle.

Indicated on display

Scheme 112

Code is only shown for vehicles with traction control system (ASR). Encode control module. See ENCODE CONTROL MODULE .

The workshop code, WSC XXXXX, identifies the workshop which performed the last coding of the control module.

1. Control module index
2. System designation
3. Hardware and software status

Scheme 113

Scheme 114

Scheme 115

1. Press --> button.

Indicated on display

Scheme 116

1. For encoding, see «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Note. Determine test preconditions. See TEST REQUIREMENTS . Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD . Check control module version (see CHECK CONTROL MODULE VERSION ) and press --> button. Press buttons -0- and -2- for "Check DTC memory" function and press -Q- button to confirm entry. Each malfunction is assigned a 5-digit DTC. It is listed in the left-hand column of the DTC table. The message identifying the malfunction and the DTC will be printed out on the printer of Scan tool V.A.G 1551 if the Print button is pressed. The DTC does not appear on the display of V.A.G 1551. The content of the DTC memory is retained until it is erased. See ERASE DTC MEMORY . Sporadic DTCs (see FUNCTION ), are additionally identified as such with "ISP" appearing on the right of the display. Static DTCs which cannot be detected when the vehicle is stationary are also identified with "ISP" after the ignition has been switched off and then on again. The following table includes all the DTCs which can be detected by the ABS Control Module (w/EDL) -J104- and displayed and printed out by V.A.G 1551. Malfunctions are listed according to DTCs.

Scheme 117

1. For warning light functions information, see «TABLE OF WARNING LIGHT FUNCTIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
2. For Output Diagnostic Test Mode, see «OUTPUT DIAGNOSTIC TEST MODE (DTM)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__output-diagnostic-test-mode-dtm)

Scheme 118

1. For ABS Wheel Speed Sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) .
4. For "read measured value block", see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
5. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 119

1. For ABS Wheel Speed Sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) .
4. For "read measured value block", see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
5. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
6. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 120

1. For ABS Wheel Speed Sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) .
4. For "read measured value block", see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
5. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
6. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 121

1. For ABS Wheel Speed Sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) .
4. For "read measured value block", see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
5. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 122

1. For DTC memory erasure, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For end output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .

Scheme 123

Scheme 124

Scheme 125

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 126

1. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 127

1. For ABS Wheel Speed Sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .

Scheme 128

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 129

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 130

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 131

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 132

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To encode the ABS Control Module, see «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 133

1. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 134

1. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 135

Scheme 136

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 137

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To check bus wires, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 138

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To check bus wires, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
4. To encode the ABS Control Module, see «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 139

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 140

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To check bus wires, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 141

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To check bus wires, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 142

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 143

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 144

1. For "Function of Bosch ABS/EDS 5.3 Series", see «FUNCTION OF BOSCH ABS 5.3 SERIES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__function-of-bosch-abs-53-series) .
2. For more information about checking control module identification, see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 145

Output Diagnostic Test Mode (DTM)

Output Diagnostic Test Mode (DTM) permits checking of the function of the control elements. The control elements are also called actuators. These are components which actuate the control module when it responds to the incoming sensor signals.

The function of the "final control elements" includes all functions and properties of the final control elements under operating conditions. This means, for example

1. An electrically operated hydraulic valve which opens and closes when activated by the control module.
2. The relay of an electric motor which starts the motor when activated by the control module. Engine starts and produces the required power.

Before running a Output Diagnostic Test Mode (DTM), it is advisable to make sure that there are no electrical DTCs in the system you wish to test. This will enable you to recognize any mechanical DTCs. Perform troubleshooting procedure as described in ROAD TEST .

Are you sure there are no electrical DTCs in the system? If yes, you will recognize the DTCs in the mechanics of the individual control elements as soon as the Output Diagnostic Test Mode (DTM) deviates from its description. In this case, replace the affected component.

Output Diagnostic Test Mode (DTM) with the Bosch ABS/EDL 5.3 system permits checking of the electrically actuated hydraulic valves and the pump motor in the hydraulic control module. You can also check that the brake lines going to the four wheels are connected correctly.

Note. The vehicle must be raised until all wheels are free to run. Ask a second mechanic to help. It must be checked whether the wheels are locked or can be turned. The -C- button can be used to exit from the test sequence at any time. To avoid overloading the "final control elements" they are only actuated during the test sequence for a period of 60 or 90 seconds. The final control test will be terminated if the "-->" button is not pressed within this period. The ABS/EDL warning light and the red brake warning light flash during the Output Diagnostic Test Mode (DTM). If the brake pedal is pressed repeatedly this will exhaust the vacuum in the brake booster. For this reason, the brake pedal must be pressed harder in order to achieve the same braking effect. It may be advisable to start the engine briefly. The vacuum in the booster is then built up again.

When implementing the Output Diagnostic Test Mode (DTM) function, the individual test steps are shown in the second line of the V.A.G 1551 display. The following abbreviations are used

I = Inlet valve

O = Outlet valve

FL = front left

FR = front right

RL = rear left

RR = rear right

VBAT = Battery voltage applied to valve

0V = No voltage at valve; 0 Volt

Locked/free = Wheel condition; must be checked by 2nd technician

Hydr-P = Hydraulic pump

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Check the control module version (see «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) ) and press the --> button.

Indicated on display

Scheme 146

1. Press buttons -0- and -3- for "Output Diagnostic Test Mode" function

Indicated on display

Scheme 147

1. Confirm input with -Q- button.

Indicated on display

Scheme 148

ABS Return Flow Pump -V39- must run. It can be heard.

When you put your foot on the brake pedal you can feel it vibrating. The brake pedal vibrates because the hydraulic pump generates pressure pulses in the brake lines. These pressure pulses induce vibrations. These are transferred to the brake pedal and the vibrations can be detected there.

The pressure pulses in the brake lines are not sufficient to lock the wheels.

Scheme 149

(Scheme 153) is a schematic diagram of the hydraulic circuit of an ABS/EDL system. This will give a better understanding of the various test steps in the Output Diagnostic Test Mode (DTM).

Scheme 150

1. The shaded components are active.
2. Thin solid lines represent hydraulic lines or hoses which are not under pressure.
3. Thick broken lines represent hydraulic lines or hoses working as suction lines.
4. Thick solid lines represent hydraulic lines or hoses which are under pressure. Press --> button.

Indicated on display

Scheme 151

1. Press --> button.

Indicated on display

Scheme 152

When you press the brake pedal, brake fluid pressure will be built up in all four wheel brake cylinders. All four wheels will be locked.

This presupposes proper functioning of the mechanical and hydraulic components of the brake system. This means, that the brake master cylinder is able to build up pressure in all wheel brake cylinders and that there are no leaks in the hydraulic connections and lines. If the wheels do not lock, perform a visual inspection of the brake fluid reservoir, the master cylinder, the ABS Hydraulic Unit and the wheel cylinders.

To start with, however, concentrate on the front left wheel. The function of the control elements for this wheel is tested first.

Note. This test step in the Output Diagnostic Test Mode (DTM) corresponds to the "pressure build-up" phase during ABS-controlled braking.

Scheme 153

1. Press --> button.

Indicated on display

Scheme 154

Keep pressing the brake pedal.

The inlet valve is actuated. It interrupts the brake line. However, the fluid pressure is still maintained in the wheel cylinder. The left front wheel remains locked.

Scheme 155

Note. This test step in the Output Diagnostic Test Mode (DTM) corresponds to the "maintain pressure" phase during ABS-controlled braking.

1. Press --> button.

Indicated on display

Scheme 156

Keep pressing the brake pedal.

The inlet valve and the outlet valve for the left front wheel are activated. The hydraulic pump starts running and reduces the fluid pressure in the wheel cylinder via the open outlet valve.

Scheme 157

The brake pedal must not give, and should press back harder against your foot.

You should now be able to turn the left front wheel.

If you cannot turn the wheel, check whether the brake line for the left front wheel is correctly connected. If this is the case, this indicates that there is a mechanical malfunction in one of the valves, providing that there is no electrical malfunction in the system. Replace the hydraulic control module.

If the brake pedal gives under your foot, this means that the inlet valve or the non-return valve connected in parallel with the inlet valve is leaking. Replace the hydraulic control module.

Note. This test step in the Output Diagnostic Test Mode (DTM) corresponds to the "pressure reduction" phase during ABS-controlled braking.

1. Press --> button.

Indicated on display

Scheme 158

ABS Return Flow Pump -V39- stops running.

Keep pressing the brake pedal. Only the inlet valve is now actuated and interrupts the brake line. Left front wheel can be turned if inlet valve is not leaking.

Scheme 159

If wheel cannot be turned, there is a leak either in the inlet valve or in the non-return valve connected in parallel with it. Replace the hydraulic control module.

1. Press --> button.

Indicated on display

Scheme 160

Keep pressing the brake pedal. Inlet valve is no longer actuated. It no longer interrupts brake line. Brake pedal sags perceptibly. Fluid pressure is built up in left front wheel brake cylinder. Wheel locks.

1. Press --> button.

Scheme 161

Indicated on display

Scheme 162

1. Press --> button.

Continue the Output Diagnostic Test Mode (DTM) in order to check the right front, left rear and right rear wheels in turn. The test steps are the same as for the left front wheel. Thus there are not described in detail.

Indicated on display

Scheme 163

1. Press --> button.

Indicated on display

Scheme 164

1. Press --> button.

Indicated on display

Scheme 165

1. Press --> button.

ABS Return Flow Pump -V39- must run.

Brake pedal must not give.

Indicated on display

Scheme 166

1. Press --> button.

ABS Return Flow Pump -V39- stops running.

Indicated on display

Scheme 167

1. Press --> button.

Brake pedal should give perceptibly.

Indicated on display

Scheme 168

1. Press --> button.

Indicated on display

Scheme 169

1. Press --> button.

Indicated on display

Scheme 170

1. Press --> button.

Indicated on display

Scheme 171

1. Press --> button.

Indicated on display

Scheme 172

1. Press --> button.

ABS Return Flow Pump -V39- must run.

Brake pedal must not give.

Indicated on display

Scheme 173

1. Press --> button.

ABS Return Flow Pump -V39- stops running.

Indicated on display

Scheme 174

1. Press --> button.

Brake pedal should give perceptibly.

Indicated on display

Scheme 175

1. Press --> button.

Indicated on display

Scheme 176

1. Press --> button.

Indicated on display

Scheme 177

1. Press --> button.

Indicated on display

Scheme 178

1. Press --> button.

Indicated on display

Scheme 179

1. Press --> button.

ABS Return Flow Pump -V39- must run.

Brake pedal must not give.

Indicated on display

Scheme 180

1. Press --> button.

ABS Return Flow Pump -V39- stops running.

Indicated on display

Scheme 181

1. Press --> button.

Brake pedal should give perceptibly.

Indicated on display

Scheme 182

1. Press --> button.

Indicated on display

1. Press --> button.

Display: Only required for vehicles with EDL and from 1998 models onward. The hydraulic pump is not actuated on vehicles before 1998 models. This test step can be disregarded on vehicles not equipped with EDL. (Scheme 187)

Scheme 183

The EDL change-over valve (left) and the EDL inlet valve (right) are actuated. ABS Return Flow Pump -V39- runs for one second. Pump draws brake fluid out of fluid reservoir. The hydraulic pump builds up brake fluid pressure in the EDL controlled wheel brake cylinders. These wheels lock.

Scheme 184

If this is not the case, this indicates that there is a mechanical malfunction in one of the valves, provided that there are no electrical DTCs in the system. Replace the hydraulic control module.

This test step cannot be performed on vehicles not equipped with EDL. These vehicles do not have the EDL valves and the pressure limiting valve.

1. Press --> button.

Indicated on display

Scheme 185

The Output Diagnostic Test Mode is complete. The ABS/EDL warning light and the brake system warning light go out.

1. Press --> button.

Indicated on display

Scheme 186

Note. If the ABS Warning Light -K47- does not go out then there is a malfunction in the system. Keep exactly to the specified test sequence. See SAFETY MEASURES AND BASIC RULES FOR TROUBLESHOOTING .

1. Press buttons -0- and -6- for the "End output" function and press the -Q- button to confirm entry.

Have you just replaced a control module with traction control function (ASR), or is one of the following DTCs stored in the DTC memory of the control module?

1. "ABS/EDL/transmission - electrical connection"
2. "Control module incorrectly encoded"
3. "CAN-bus - No message from transmission control module"

The control module must be coded according to the type of engine and transmission.

Note. The coding can only be performed if a workshop code is stored in V.A.G 1551. See Operating instructions for V.A.G 1551. The 5-digit coding will appear when the control module identification is displayed.

1. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Check the control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) and press the --> button.
3. Press --> button.

Indicated on display

Scheme 187

1. Press buttons -0- and -7- for "Coding control module" function.

Indicated on display

Scheme 188

1. Confirm input with -Q- button.

Indicated on display

Scheme 189

Scheme 190

Scheme 191

1. Enter the required code number and confirm with -Q- button.

The display shows the control module identification and the code entered (For example, 00000).

Scheme 192

1. Press --> button.

Indicated on display

Scheme 193

1. Press buttons -0- and -6- for the "End output" function and press the -Q- button to confirm entry.

The control module can transfer measured values to the Scan tool V.A.G 1551. These measured values deliver information about the status of the system and the connected sensors. In many cases the transferred measured values can be used to assist with troubleshooting and malfunction correction. The measured values available from the Bosch type 5.3 ABS are grouped in four display groups, which can be called up via display group numbers.

1. Observe the safety precautions applicable to test drives. See «ROAD TEST»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. Connect Scan tool V.A.G 1551 and select "Brake electronics" with address word 03. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . NOTE: When the printer is switched on, the contents of the display will be printed out on the Scan tool log. When "Read measured value block", also check wiring and connectors for loose connections.
3. Check the control module version. See «CHECK CONTROL MODULE VERSION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) and press the --> button.

Indicated on display

Scheme 194

1. Press buttons -0- and -8- for "Read measured value block" function.

Indicated on display

Scheme 195

1. Confirm input with -Q- button.

Indicated on display

Scheme 196

1. Press buttons -0-, -0- and -1-.
2. Confirm input with -Q- button.

1. The display zones 1 to 4 show the actual wheel speeds at the tire circumference in km/h. These are calculated by ABS Control Module (w/EDL) -J104- on the basis of the pulses received from the wheel speed sensors. If one of the display zones shows no reading, proceed as for DTCs 00283, 00285, 00287, 00290 "Speed sensor". See «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. In order to check that the speed sensor signals are correctly assigned to the four wheels, the vehicle must be raised. On vehicles with manual transmission put the gear lever in neutral. On vehicles with automatic transmission move the selector lever to position "N". Turn appropriate wheel by hand. The other wheels must be prevented from rotating.
3. When the vehicle is accelerated uniformly on a dry surface, the displayed values will increase continuously in rising whole numbers, e.g .... 6 km/h, 7 km/h, 8 km/h .... The difference between displayed values 1 to 4 should be no more than +/- 1 km/h(rounding errors).If the values jump, for instance from ... 6 km/h, 7 km/h, to 12 km/h ... or if the difference between the displayed values is greater than +/- 1 km/h then check the installation of the wheel speed sensors and rotors.

See SUSPENSION - FRONT .

See SUSPENSION - REAR .

Scheme 197

By pressing the buttons <-1 and 3-> the display group numbers may be selected consecutively.

1. Press button -C- in order to enter the display group number manually.

Indicated on display

Scheme 198

1. Press buttons -0-, -0- and -2-.
2. Confirm input with -Q- button.

Test table, Display group 2

1. For more information about performing an electrical check, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 199

By pressing the buttons <-1 and 3-> the display group numbers may be selected consecutively.

1. Press button -C- in order to enter the display group number manually.

Indicated on display

Scheme 200

Note for display group 3

If display zones for engine speed and actual engine torque are to be read out with engine running communication between Scan tool and control module must be terminated with "End output" function, see END OUTPUT . Then start engine and set up diagnostic link between Scan tool and control module again.

1. Press buttons -0- and -8- for "Read measured value block" function.
2. Confirm input with -Q- button.
3. Press buttons -0-, -0- and -3-.
4. Confirm input with -Q- button.

Scheme 201

1. For more information about performing an electrical check, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For the DTC table, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

By pressing the buttons <-1 and 3-> the display group numbers may be selected consecutively.

1. Press button -C- in order to enter the display group number manually.

Indicated on display

Scheme 202

1. Press buttons -0-, -0- and -4-.
2. Confirm input with -Q- button.

Scheme 203

1. For vehicles for which the On Board Diagnosis (OBD) does not give any indication of the source of the DTC the complete electrical check must be worked through.
2. In vehicles in which the self- diagnosis provides a direct indication of the source of the DTC only perform the test steps recommended in the DTC table (specific testing).

Scheme 204

1. An "Automatic test sequence" must first be performed to establish that any DTCs present in the transmission and Engine Control Module (ECM)s can only originate from the ABS/EDL. Connect up Scan tool V.A.G 1551 and select address word 00 with ignition switched on. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . After completing the "Electrical check", check and erase the DTC memories of the transmission and Engine Control Module (ECM).
2. Make sure multiple connector between wiring harness and ABS Control Module (w/EDL) -J104- is in perfect condition, i.e. not bent, broken or corroded terminals. Replace any damaged terminals using wiring repair kit VAS 1978. NOTE: The instructions supplied with wiring repair kit VAS 1978 normally do not permit repairs to the wiring of the ABS and its associated systems. However, this only applies to the screened wiring in the systems.
3. Switch ignition and electrical consumers off before commencing the check (headlights, lighting, fan, etc.).

The following equipment is required

1. VAG 1598 Test box
2. 1598/27 Adapter
3. VAG 1594 Adapter cable set
4. VAG 1526 Hand-held multimeter

Connecting test box VAG 1598 with adapter 1598/27

1. Switch ignition off.
2. Connect adapter VAG 1598/27 to test box VAG 1598. Disconnect multi-pin connector from ABS Control Module (w/EDL) -J104-. Connect adapter VAG 1598/27 and test box VAG 1598 to connector of ABS/EDL wiring harness.

The socket designations on test box VAG 1598 are identical with the terminal designations on ABS Control Module (w/EDL) -J104- and the designations of the connector on the wiring harness.

Terminal assignment of wiring harness/ABS Control Module (w/EDL) -J104- multiple connector.

Scheme 205

Note. All terminals not listed are currently not assigned and must not be connected to other components!

Scheme 206

Scheme 207

Scheme 208

Note on DTC table

1. The socket descriptions of test box VAG 1598 are identical to the terminal descriptions of ABS Control Module (w/EDL) -J104- in the current flow diagram. Incorrect test procedures can cause system damage. Do not make connections between any terminals other than those listed in the test table.
2. The specified values refer to the readings obtained on tester VAG 1526 and are not necessarily applicable to other test units.
3. If the readings obtained do not match the specified values, carry out the DTC remedy measures in the right-hand part of the table. See the appropriate System Wiring Diagrams article.
4. If the specified values are achieved, also check wiring for loose connections and short circuit to positive and Ground (GND). This applies especially to sporadic DTCs.
5. Only use test lead set VAG 1594 for checking continuity (bridging leads).
6. If the measured figures only differ slightly from the specified values, clean the sockets and plugs of the testers and test leads (with terminal spray G 000 700 04) and repeat the check. Before replacing components, check wiring and connections again. This is particularly important if the specification calls for a resistance reading of less than 10 ohm..

Scheme 209

Scheme 210

Scheme 211

Scheme 212

Scheme 213

Scheme 214

Scheme 215

Scheme 216

Scheme 217

Scheme 218

Scheme 219

Scheme 220

Scheme 221

Scheme 222

1. For brake light switch information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system)
2. For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03).
3. For more information about front speed sensor lines, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
4. For more information about connecting V.A.G. 1551, see «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
5. For checking the DTC memory, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
6. For erasing the DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Electronic Stabilization Program (ESP)

The Electronic Stabilization Program (ESP) is a driving dynamics regulation system. It stabilizes the vehicle both in understeer and oversteer situations.

ESP is an addition to the driving safety systems

ESP increases the ability to control the vehicle during critical driving situations. It reduces the likelihood of skidding and improves steering control.

It can only function within physical limits

Safety measures and troubleshooting basics

ESP is a vehicle safety system. The technician must understand the system completely before working on the system.

1. If the On Board Diagnostic (OBD) has recognized a malfunction in the system, the ABS Warning Light -K47-, the symbol for "Brake system malfunction" and the Traction Control Indicator Light -K86- are lit when the ignition is switched on. The red brake warning light for "Brake system malfunction" appears in the display of the driver information system. The ABS/EDL and ASR/ESP indicator lights are located below the display. For additional information, see the section entitled "Indicator light functions, overview". See «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__check-dtc-memory) .
2. If the ABS Warning Light -K47- and the red brake warning light for" Brake system malfunction" are not lit, but the brake system is not functioning properly, check for malfunctions in the mechanical/hydraulic brake system components. See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .

Scheme 223

Test drive

1. Some DTCs are only recognized by the On Board Diagnostic while the vehicle is moving. You can check the system by carrying out a test drive. During the test drive, drive at 60 km/h for 30 seconds. Make sure the traffic is clear and then brake hard enough to activate the ABS. You will feel a pulsing in the brake pedal indicating the system is active.

If the customer has reported a malfunction or problem, troubleshoot according to the customer complaint

1. First switch the ignition on, and note whether the indicator lights light up. The table in «INDICATOR LIGHT FUNCTIONS, OVERVIEW»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__indicator-light-functions-overview) will provide a starting point.
2. Observe test conditions. See «TEST CONDITIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-conditions) .
3. Connect the VAG1551 scan tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
4. Check the control module version (see «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) ) and press --> button.
5. Check DTC memory. See «DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . If a DTC is stored: make a note of the DTC and erase the DTC memory. See «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
6. End data transfer using the "End Output" function. See «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
7. Repair the malfunction with the help of the DTC table. See «DTC TABLE; DTCS 00000 TO 00526»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . Select again the address word 03 "Brake Electronics." Check and erase DTC memory.
8. End data transfer using the "End Output" function. Disconnect VAG1551 scan tool.
9. Make sure all connections are connected properly. Carry out a test drive. See «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) . The indicator lights must not light up during the drive. If the indicator lights light up during the test drive, repeat the troubleshooting procedure. NOTE: If the control module connector is disconnected during the drive, an unfounded DTC may be stored in the memory of another control module. The mechanical and hydraulic brake system functions will continue to work. However, with a system failure the brake pressure regulator is deactivated meaning there is an increased chance of an accident while driving. CAUTION: On vehicles equipped with Audi Telematics by OnStar(R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting the vehicle battery. See «EXAMPLE: SWITCH OFF EMERGENCY (BACK-UP) BATTERY»(/audi/a8/d3-2002-2005/remont/communication-devices/#on-board-diagnostic-obd-radio-navigation-steering-telematics__example-switch-off-emergency-back-up-battery) . Switch-on the emergency (back-up) battery after reconnecting the vehicle battery. See «EXAMPLE: SWITCH ON EMERGENCY (BACK-UP) BATTERY»(/audi/a8/d3-2002-2005/remont/communication-devices/#on-board-diagnostic-obd-radio-navigation-steering-telematics__example-switch-on-emergency-back-up-battery) . Switch ignition off before carrying out any work on vehicle. Determine anti-theft radio code for radios with anti-theft radio code and disconnect battery Ground (GND) strap.
10. Remember that there are certain procedures that must be carried out after connecting the battery, such as: setting the clock. Read procedures under «RECONNECTING BATTERY, PROCEDURES»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__reconnecting-battery-procedures) .
11. Only replace a malfunctioning component if you are certain that all electrical lines to this components are functioning properly. The lines must work properly and be capable of carrying all signals without any problems. Check the lines for the following: Corrosion or loose connections in the connectors or Ground (GND) straps. If there are bent, broken or corroded terminals on the connectors, replace the terminals using VAS1978 wiring harness repair kit. Open circuit in wiring Short circuit to B+ or Ground (GND) NOTE: The instruction manual for the VAS1978 wiring harness repair kit generally forbids the repair of any lines in the ESP or related systems. This rule only pertains to the shielded lines in these systems.
12. When replacing a control module, make sure you install the correct control module. First check the control module version. The version is displayed after the communication is established between the VAG1551 scan tool and the control module, in the VAG1551 display, or after selecting the "Check Control Module Versions" function 01. See «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) . You can also determine which equipment is installed in the vehicle using the letter combinations on the vehicle data label. 1AC: Anti-lock Brake System (ABS) 1AH: Anti-lock Brake System with Electronic Differential Lock (ABS/EDL) 1AJ: Anti-lock Brake System with Electronic Differential Lock and traction control system (ABS/EDL/ASR) 1AT: Anti-lock Brake System with Electronic Differential Lock and traction control system (ABS/EDL/ASR) and Electronic Stabilization Program (ESP) All work on the ABS Hydraulic Unit must be carried out with the utmost cleanliness. Thoroughly clean the hydraulic line connections and the area around them. Do not use any aggressive cleaning agents, such as brake fluid, gasoline, thinning agents, or any fluids containing mineral oil, such as oils and greases. Do not disconnect hydraulic lines until you have cleaned the connections. Note the appropriate precautions regarding handling of brake fluid. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) . Place removed parts on clean surface and cover them. Only use lint-free cloths. Only use genuine packaged parts, and only remove replacement parts from their packaging immediately prior to installation. Bleed brake system if connections in system have been opened. See «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) . Welding using electrical welding equipment can affect the ESP system.

Test conditions

1. Vehicle equipped with approved wheel and tire sizes, which must be the same on all four wheels. All tire inflation pressures checked according to specifications.
2. Mechanical and hydraulic parts of brake system in good condition; no leaks in hydraulic lines and connections (visually inspect ABS Hydraulic Unit, brake calipers, tandem master brake cylinder).
3. Wheel bearings and wheel bearing play OK See «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. Wheel speed sensors installed correctly See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
5. Supply voltage must be OK (not less than 10.0 volts).
6. Parking brake released
7. Harness connector on ABS Control Module (w/EDL) -J104- properly connected, with retainer catch engaged.
8. The OBD sequence can only be started with the vehicle stationary and the ignition switched on (or with the engine running). The diagnosis cannot be started if wheel speed exceeds 2.75 km/h (1.75 MPH), and will be terminated if the speed exceeds 20 km/h (13 MPH).
9. While testing the ESP system, make sure that the vehicle's electrical system is not subjected to electromagnetic interference; keep the vehicle away from equipment with a high current draw such as electric welding units.

Technical information required

1. Applicable electrical wiring diagrams See appropriate System Wiring Diagrams article.
2. Installation locations of electrical components: See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. Brake mechanical information: See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
4. Brake hydraulic information: See «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
5. Information on repairing common malfunctions on current models (as applicable).

ESP function

ESP includes the functions of EBD, ABS, EDL and ASR. The individual components have the following functions

EBD

The two brake circuits are split diagonally. One circuit supplies the left-front and right-rear brakes with appropriate hydraulic pressure, the other supplies the right-front and left-rear.

Matched software in the ABS Control Module (w/EDL) -J104-, Electronic Brake Distribution (EBD) carries out the function of the mechanical/hydraulic brake pressure regulator.

The signal sent to the instrument cluster when the ABS fails is pulsed, if the EBD function continues in emergency mode. The instrument cluster distinguishes between no signal, a pulsed signal, and a steady signal. The ABS/EDS indicator light and the red symbol for "Brake system malfunction" light accordingly.

Scheme 224

1. Terminal 15
2. Signal for controlling the ABS/EDL indicator light and the red brake warning symbol
3. Voltage supply for the ABS/EDL indicator light
4. Voltage supply for the red brake warning symbol

Scheme 225

1. In interval "A" (with "ignition on(" a self-test of the ABS/EDL indicator light is carried out for two seconds using signal "2" (light lights up). During this interval, the instrument cluster suppresses the red brake warning symbol.
2. Signal "2" is not available in interval "B." The ABS/EDL indicator light and the red brake warning symbol do not light.
3. In interval "C", the On Board Diagnostic recognized a DTC, which did not deactivate the EBD. Signal "2" is pulsed. Only the ABS/EDL indicator light comes on.
4. In interval "D", the On Board Diagnostic recognized a DTC, which did deactivate the EBD. Signal "2" is steady. The ABS/EDL indicator light and the red brake warning symbol light.

The red brake warning symbol indicates the EBD is deactivated. The vehicle is only allowed to be driven under restricted conditions. Test Drive the vehicle, see TEST DRIVE .

For additional information about EBD indicator light control, see: "Indicator light functions, overview". See INDICATOR LIGHT FUNCTIONS, OVERVIEW .

ABS prevents the wheel from locking up during hard braking initiated by the driver. ABS regulates the brake system pressure in the individual brake cylinders with respect to the individual wheel speed, brake deceleration and slip, to ensure optimal braking of the wheels on the road surface.

The Electronic Differential Lock (EDL) is a traction control aid for driving away from a standstill. An electronically-controlled brake application at the wheel that is spinning provides a torque reaction point for the differential. This enables the wheel with better traction to make use of the engine power. EDL is effective in both forward and reverse.

On vehicles with all-wheel-drive, EDL controls all four wheels. This makes it possible to eliminate the driver operated mechanical differential lock.

EDL as part of ESP and is effective at any speed.

The function of ASR requires an exchange of signals between the ABS Control Module (w/EDL) -J104-, the Engine Control Module (ECM) and the Transmission Control Module (TCM) (only for vehicles with automatic transmission). The control modules communicate with each other.

The data is transferred via CAN-bus. See CAN-BUS, FUNCTION .

The ASR traction control system prevents the driven wheels from spinning under acceleration; the system operates by reducing engine torque and is active at all speeds. The EDL and ASR functions are combined in order to assist acceleration.

ESP

The Electronic Stabilization Program (ESP) is a driving dynamics regulation system. It stabilizes the vehicle both in understeer and oversteer situations. ESP regulation includes the functions of EBD, ABS, EDS and ASR. A special function of ESP is that it can brake individual wheels.

Examples

During over-steering, the rear of the vehicle breaks out toward the outside of the curve. The vehicle rotates more on its vertical axis than required to maneuver through the curve. Braking the outside front wheel counters the over-steering effect.

Scheme 226

In under-steering, it is the front of the vehicle that does not follow the curve. The front of the vehicle breaks out. The vehicle rotates less on its vertical axis than is required to maneuver through the curve. Braking the inside rear wheel counters the under-steering effect.

Scheme 227

The component locations (except for the new components) are the same as the Bosch 5.0 components. The procedures for removal and installation of the components are found in ANTILOCK BRAKE SYSTEM .

Hydraulic pump for traction control -V156- and the sensor for brake pressure -G201

The hydraulic pump for traction control -V156- and the sensor for brake pressure -G201- are located in the engine compartment on the left (in the direction of travel) underneath the ABS Hydraulic Unit -N55-.

The ABS Hydraulic Unit -N55- and ABS return flow pump -V39- are supported by the hydraulic pump for traction control -V156-. This ensures brake pressure is quickly increased in the brake cylinders at each wheel, as needed.

Scheme 228

Do not remove any bolts from the individual components, such as the ABS Hydraulic Unit -N55- and the hydraulic pump for traction control -V156-. The hydraulic pump for traction control -V156- and the sensor for brake pressure -G201- comprise one unit and must always be replaced as a set.

The sensor for brake pressure -G201- measures the build up of brake fluid pressure in the brake system.

Steering Angle Sensor -G85

There are two different versions of steering angle sensor -G85-.

In conjunction with control module 4D0 907 389, the steering angle sensor -G85- is installed over the shaft of the steering column.

Scheme 229

The sensor cannot be replaced individually. In the event of a malfunction on the sensor the entire steering column needs to be replaced.

See ANTILOCK BRAKE SYSTEM .

The steering angle sensor -G85- is housed together with the airbag spiral spring/return spring with slip ring -F138-.

Airbag spiral spring/return spring with slip ring -F138

The airbag spiral spring/return spring with slip ring -F138- is installed on the steering column shaft and secured to the steering wheel switch.

The airbag spiral spring/return spring with slip ring -F138- may be installed with or without lines for steering wheels with additional functions. The illustration shows steering wheels with additional functions.

See Parts catalog.

Scheme 230

The removal and installation procedures for the steering angle sensor -G85- are identical to those for the airbag spiral spring/return spring with slip ring -F138- are described in appropriate Air Bag Restraint Systems article.

The steering angle sensor -G85- does not have its own DTC memory. It is monitored using the DTC memory of the ABS Control Module (w/EDL) -J104- via the CAN-bus.

Scheme 231

Steering angle sensor -G85- is supplied with voltage through a line connected to terminal 30. After the ignition is switched off, the sensor still uses the voltage for an hour. During this hour, the current used is a maximum 100 mA. After this hour, current used is less than 0.5 mA; the sensor is no longer active. When the ignition is switched on, the sensor is activated via terminal 15.

The current pulled from terminal 30 after the ignition is switched off is required to be able to detect a turn of the steering wheel after the ignition is off.

If the ignition was off more for than an hour, the sensor always reports a steering angle of 0 degrees. The steering angle is correctly detected only after the steering wheel was turned more than 4.5 degrees.

Sender for rotation rate -G202

Sender for rotation rate -G202- is installed under the driver's seat (in bottom of illustration, below -G200-)

Scheme 232

This sensor measures the rotation of the vehicle around its vertical axis (yaw).

Bolt tightening torque: 5 Nm

Sensor for transverse acceleration -G200

Installed under the drivers' seat (in top of illustration, above -G202-)

Scheme 233

Be careful!

The sensor for transverse acceleration is sensitive to strong vibrations.

If the sensor drops on the ground, full function of the sensor is no longer guaranteed. If this is the case, you cannot reuse the sensor.

Bolt tightening torque: 2 Nm

The parking brake switch

Informs the ABS Control Module (w/EDL) -J104- if the parking brake is set or released. This is important as the parking brake influences ESP control.

The ABS solenoid valve relay -J106- and the ABS return flow pump relay -J105

Are no longer installed in the ABS Hydraulic Unit -N55- as in the Bosch 5.0 system. They are now installed in the relay carrier under the driver's side storage compartment.

See appropriate System Wiring Diagrams article.

ABS/ESP Control Module CAN Bus

The function of the ESP requires that the ABS Control Module (w/EDL) -J104- (item -2-) transfer data to and from the Engine Control Module (ECM) (item -3-), the Transmission Control Module (TCM) (item -4-) and the steering angle sensor -G85- (item -1-).

The data is transferred via the CAN-bus. For information and test procedure, see TWO-LINE BUS SYSTEM, CHECKING . The CAN-bus only contains two lines. These are called bus lines. These transfer all required data. Two bus lines are used to be able to detect malfunctions in the lines.

Scheme 234

The CAN-bus is connected in the Engine Control Module (ECM) with a resistance of approximately 66 ohm. All other control modules connected to the CAN system (for example the ABS Control Module (w/EDL) -J104-) are connected with a high ohm resistance (2.6 k ohm).

The ASR and ESP functions can be switched on and off using the ASR/ESP switch on the center console. If the driver steps on the brake pedal, the status of the ESP switch is ignored. When braking, ESP is always active. When the ignition is switched on, the ASR and ESP functions are activated.

You can check the function of the ASR/ESP switch by selecting the "Read Value Measuring Block" function 08. See MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING , Display group 002.

When switched off, the ASR/ESP indicator light is lit up in the instrument cluster. During normal operation the indicator light blinks three times per second.

Indicator light functions, overview

1. First switch the ignition on, and note whether the indicator lights in the instrument cluster lights up. The status of the ABS warning light -K47-, the red brake warning symbol, and the traction control indicator light -K86- provide an initial indication of the current condition.

The red symbol for "Brake system malfunction" appears in the display of the driver information system.

Scheme 235

The ABS warning light -K47- and the traction control indicator light -K86- are located below the display.

Scheme 236

Scheme 237

Scheme 238

Scheme 239

Scheme 240

Scheme 241

Scheme 242

Scheme 243

Scheme 244

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To check DTC memory, see «DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
3. For "read measuring value block", see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
4. To check basic setting, see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .

On Board Diagnostic (OBD), specific functions

The OBD function of the ESP system can recognize malfunctions and store a total of 41 different Diagnostic Trouble Codes (DTCs).

Note. If a malfunction is recognized by OBD, the system concerned is switched off automatically for the duration of the current driving cycle. This is indicated by the relevant warning light in the instrument cluster. See INDICATOR LIGHT FUNCTIONS, OVERVIEW for more information.

Note. The above does not apply to the DTC "01119 gear recognition signal" DTC table starting on DTC TABLE; DTCS 00000 TO 00526 . If this DTC is recognized, no warning light goes on. This malfunction affects the front and reverse gear recognition function. The ABS Control Module (w/EDL) -J104- can determine the gear using plausibility criteria.

If VAS5051 tester or VAG1551 scan tool was connected and is communicating with the ABS Control Module (w/EDL) -J104- no regulation is possible. The ABS warning light -K47-, traction control indicator light -K86- and the red brake warning symbol are lit.

Each time the ignition is switched on, the system conducts a self-test. The yellow ABS warning light -K47- and the traction control indicator light -K86- come on to indicate that this self-test is being conducted. The lights go out after about 3 seconds. The self-test continues after the vehicle starts moving, as certain malfunctions cannot be recognized until the vehicle is moving.

The self-test may be recognized by the switching of relays, the clicking of valves, the start-up noise of the ABS return flow pump (at the ABS Hydraulic Unit) and the pressurizer pump, and by a slight vibration at the brake pedal (usually at about 6 km/h).

These system-related effects are part of the self-test program, and this should be explained to the customer in the event of complaints.

On Board Diagnostic (OBD), technical data

Diagnostic Trouble Code (DTC) memory

1. Permanent memory; the contents are retained even if the power supply is switched off. Data output
2. Rapid data transfer (operating mode 1).
3. The ABS warning light -K47-,the red brake warning symbol, and the traction control indicator light -K86- in the instrument cluster are lit, when a malfunction is detected and the relevant system is switched off.

ON BOARD DIAGNOSTIC (OBD) - ABS WITH ESP SYSTEM

1. Use VAS5051 tester or VAG1551 scan tool for On Board Diagnostic.

Control module versions (scan tool function 01), checking

1. Connect VAS5051 tester or VAG1551 scan tool and select address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . NOTE: The following explanations refer to the use of the VAG1551 scan tool. A similar procedure is used for the VAS5051 tester for On Board Diagnostic.
2. Advance through program sequence by pressing --> button.

Indicated on display

Scheme 245

1. Press buttons -0- and -1- to select "Check Control Module Version" 01. Press -Q- button to confirm input.

Note. Refer to the parts catalog for the correct ABS Control Module (w/EDL) -J104- for the vehicle.

Indicated on display

Scheme 246

Scheme 247

1. ABS control module Part. No. including control module version
2. System designation
3. Hardware and software status

DTC table

1. Observe test conditions, see «TEST CONDITIONS»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-conditions) .
2. Connect VAS5051 tester or VAG1551 scan tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
3. Check the control module version. See «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) and press --> button.
4. Press buttons -0- and -2- to select "Check DTC Memory" function 02. Press -Q- button to confirm input.
5. Every malfunction that the system can detect has a 5-digit Diagnostic Trouble Code (DTC), which is listed in the left-hand column of the DTC table. If the printer is switched on by pressing the "PRINT" button, the VAG1551 scan tool (ST) prints out a message identifying the malfunction and the DTC. Otherwise, DTCs are not displayed by the VAG1551 scan tool.
6. The contents of the DTC memory remain stored until the memory is erased. See «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
7. Sporadic malfunctions (see «ON BOARD DIAGNOSTIC (OBD)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) ) are identified by "ISP" appearing on the right-hand side of the display.
8. Static malfunctions that cannot be detected when the vehicle is stationary are also identified with "ISP" if the ignition has been switched off and then on again.
9. The following DTC table includes all the DTCs that can be stored by the ABS Control Module (w/EDL) -J104- and displayed and printed out by the VAS5051 tester or VAG1551 scan tool. Malfunctions are listed according to the DTC number.

Scheme 248

Scheme 249

1. For "read measuring value block" and related information. See «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For Indicator light functions, see «INDICATOR LIGHT FUNCTIONS, OVERVIEW»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__indicator-light-functions-overview) .
3. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 250

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 251

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 252

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 253

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 254

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 255

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 256

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 257

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 258

Scheme 259

1. For ABS wheel speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
5. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 260

1. For ABS wheel speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
5. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 261

1. For ABS wheel speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
5. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 262

1. For ABS wheel speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
3. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
4. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
5. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 263

Scheme 264

Scheme 265

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 266

Scheme 267

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 268

Scheme 269

Scheme 270

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For information regarding the ABS Control Module, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
4. For master cylinder and brake booster information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .

Scheme 271

Scheme 272

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 273

1. For rotor information, see «DISC»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
2. For wheel bearing information, see «SUSPENSION - FRONT»(/audi/a8/d3-2002-2005/remont/suspension-front/#suspension-front) or «SUSPENSION - REAR»(/audi/a8/d3-2002-2005/remont/suspension-rear/#suspension-rear) .
3. For ABS wheel speed sensor information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
4. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 274

Scheme 275

Scheme 276

Scheme 277

Scheme 278

1. For "ESP Functions", see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
2. For steering angle sensor, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) . For installation information, see «STEERING»(/audi/a8/d3-2002-2005/remont/electronic-steering/#steering) .
3. For "Login Procedure", see «CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__code-control-module-scan-tool-function) .
4. For ABS control module (w/EDL) -J104-coding, see «CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__code-control-module-scan-tool-function) .
5. For "Basic Setting", see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .
6. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
7. For suspension alignment information, see «SPECIFICATIONS & PROCEDURES»(/audi/a8/d3-2002-2005/remont/wheel-alignment/#specifications-procedures) .

Scheme 279

1. For ABS control module (w/EDL) -J104-coding, see «CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__code-control-module-scan-tool-function) .

Scheme 280

1. For "ESP Functions", see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .

Scheme 281

Scheme 282

Scheme 283

Scheme 284

1. For A/C Control Module information, see «ON BOARD DIAGNOSTIC (OBD)»(/audi/a8/d3-2002-2005/remont/heated-glassdefoggers/#on-board-diagnostic-obd-hvac-can-defrosters) .
2. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .

Scheme 285

Scheme 286

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 287

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 288

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 289

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 290

Scheme 291

Scheme 292

Scheme 293

Scheme 294

1. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. To replace hydraulic pump for traction control -V156-, see «HYDRAULIC PUMP FOR ELECTRONIC STABILIZATION PROGRAM (ESP), REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 295

Scheme 296

Scheme 297

Scheme 298

Scheme 299

Scheme 300

Scheme 301

Scheme 302

Scheme 303

Scheme 304

1. For transverse acceleration sensor information, see «SENSOR FOR TRANSVERSE ACCELERATION -G200- AND SENDER FOR ROTATION RATE -G202-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
4. For "Basic Setting", see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .
5. For End Output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
6. For test drive information, see «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) .
7. For Electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 305

Scheme 306

1. For transverse acceleration sensor information, see «SENSOR FOR TRANSVERSE ACCELERATION -G200- AND SENDER FOR ROTATION RATE -G202-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 307

Scheme 308

Scheme 309

Scheme 310

Scheme 311

Scheme 312

Scheme 313

Scheme 314

1. For brake light switch replacement, see «BRAKE LIGHT SWITCH, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
2. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
3. To replace hydraulic pump for traction control -V156-, see «HYDRAULIC PUMP FOR ELECTRONIC STABILIZATION PROGRAM (ESP), REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
4. For brake bleeding information, see «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
5. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
6. To erase DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
7. For End Output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
8. For test drive information, see «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) .

Scheme 315

Scheme 316

1. To erase DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For End Output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
3. For test drive information, see «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) .
4. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 317

1. For "Basic Setting", see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .

Scheme 318

Scheme 319

Scheme 320

Scheme 321

Scheme 322

Scheme 323

Scheme 324

Scheme 325

Scheme 326

Scheme 327

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For "Basic Setting", see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .
3. To erase DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. For End Output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
5. For test drive information, see «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) .
6. To replace sender for rotation rate -G202-, see «SENSOR FOR TRANSVERSE ACCELERATION -G200- AND SENDER FOR ROTATION RATE -G202-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
7. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
8. To erase DTC memory, see «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
9. For End Output, see «END OUTPUT»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__end-output) .
10. For test drive information, see «TEST DRIVE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__test-drive) .

Scheme 328

Scheme 329

Scheme 330

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
3. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 331

Scheme 332

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
3. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 333

Scheme 334

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
3. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. To replace the steering angle sensor -G85-, see «STEERING ANGLE SENSOR -G85-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system__steering-angle-sensor-g85-removing-and) .
5. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 335

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .

Scheme 336

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
2. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 337

Scheme 338

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
3. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. To replace ABS Control Module (w/EDL) -J104-, see «ABS CONTROL MODULE (W/EDL) -J104-, REMOVING AND INSTALLING»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Scheme 339

1. For "read measuring value block" and related information, see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) .
2. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
3. For CAN-bus lines, see «TWO-LINE BUS SYSTEM, CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Scheme 340

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .
2. To check control module version, see «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) .

Scheme 341

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .

Scheme 342

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .

Scheme 343

1. For ESP Functions, see «ESP FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__esp-function) .

Scheme 344

Basic setting (scan tool function 04)

Note. Initiating "Basic Setting" function 04 does the following for ESP

The steering angle sensor -G85- is zeroed using display group 1. See DISPLAY GROUP 1: ZEROING THE STEERING ANGLE SENSOR -G85-.

Before you can zero the sensor, you must have successfully carried out the "Login Procedure" function 11 using the VAG1551/1552 scan tool (see LOGIN PROCEDURE (SCAN TOOL FUNCTION 11) ) and the ABS Control Module (w/EDL) -J104- must be coded (see CODE CONTROL MODULE (SCAN TOOL FUNCTION 07) ).

The hydraulic pump for traction control -V156- is activated using display group 2

Activation of the hydraulic pump for traction control -V156- does not require any preparations. It is used to bleed the hydraulic system. See DISPLAY GROUP 2: ACTIVATING HYDRAULIC PUMP FOR TRACTION CONTROL -V156 .

The ESP driving test is activated using display group 3

The ESP driving test is used to test the plausibility of the signals from the sensor for transverse acceleration, sender for rotation rate and pressure sensor. See DISPLAY GROUP 3: ACTIVATING ESP DRIVING TEST .

Login procedure (scan tool function 11)

Note. In order to carry out this function, the dealer code in the VAG1551/VAG1552 scan tool must have been entered. This is the dealer code for your dealership.

See Operating manual for VAG1551 scan tool, information about OBD

Indicated on display

Scheme 345

1. Press buttons -1- and -1- to select "Login Procedure" function 11.

Indicated on display

Scheme 346

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 347

1. Enter the relevant code for the vehicle and press -Q- button to confirm input.
2. The code for logging in for zeroing of steering angle sensor -G85- is 40168.
3. For the codes for logging in to code the ABS Control Module (w/EDL) -J104-, see «TEST SEQUENCE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Display group 1: Zeroing the steering angle sensor -G85

Zeroing of the steering angle sensor -G85- must be accurate to + 5 degrees.

The steering angle sensor -G85- must be zeroed

1. If the ABS Control Module (w/EDL) -J104-, the steering angle sensor -G85-, or the steering column was replaced
2. After coding the ABS Control Module (w/EDL) -J104
3. If adjustments were made to the running gear
4. If you found a DTC in the DTC memory of the ABS Control Module (w/EDL) -J104- and the DTC table indicated the sensor needs to be zeroed.

1. Turn the engine on.
2. Turn the steering wheel one turn to the right and one turn to the left.
3. On a level surface, carry out a short test drive. Drive straight ahead and do not exceed 20 km/h.
4. If the steering wheel is level during the test drive, stop the car.
5. Zero the sensor (see the page after the next page).

Do not move the steering wheel.

Do not switch ignition off.

or

1. If the steering wheel is not level, check the wheel alignment and adjust as necessary. See «WHEEL ALIGNMENT PROCEDURES»(/audi/a8/d3-2002-2005/remont/wheel-alignment/#specifications-procedures__wheel-alignment-procedures) .
2. Check the suspension geometry and center the steering according to the operation manual for the alignment machine. This means you adjust the front wheels to face directly ahead.
3. Zero the sensor.

Do not move the steering wheel.

Do not switch ignition off.

1. Connect VAS5051 tester or VAG1551 scan tool and select the address word 03 "Brake Electronics", see «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .

Indicated on display

Scheme 348

1. Press buttons -1- and -1- to select "Login Procedure" function 11.

Indicated on display

Scheme 349

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 350

1. Press buttons -4-, -0-, -1-, -6- and -8- to input code 40168. Press -Q- button to confirm input.

Indicated on display

Scheme 351

1. Press buttons -0- and -4- to select "Basic Setting" function 04.

Indicated on display

Scheme 352

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 353

1. Press buttons -0-, -0- and -1-. Press -Q- button to confirm input.

If this appears in display, the "Login Procedure" has not been successfully carried out

Scheme 354

Indicated on display

Scheme 355

1. Check the zero position using "Read Measuring Value Block" function 08 (see «MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__measuring-value-block-scan-tool-function) ) and display group 5 (Scheme 45)

or

Indicated on display

Scheme 356

Note. If message in (Scheme 361) appears, perform the following sequence.

1. Check DTC memory. See «DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING.»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
2. Erase DTC memory. See «ERASE DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. Switch ignition off.
4. Switch ignition on.
5. Then repeat zeroing.
6. Advance through program sequence by pressing --> button.

Indicated on display

Scheme 357

or

Indicated on display

Scheme 358

If the message in (Scheme 363) appeares, the steering wheel was not rotated one turn to the right and one turn to the left.

1. Switch ignition off.
2. Switch ignition on.
3. Then repeat zeroing.
4. Advance through program sequence by pressing --> button.

Indicated on display

Scheme 359

Display group 2: Activating hydraulic pump for traction control -V156

The hydraulic pump for traction control -V156- is activated to bleed the hydraulic system.

See BLEEDING BRAKE SYSTEM .

1. Connect the VAG1551 Scan Tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .

Indicated on display

Scheme 360

1. Press buttons -0- and -4- to select "Basic Setting" function 04.

Indicated on display

Scheme 361

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 362

1. Press buttons -0-, -0- and -2-. Press -Q- button to confirm input.

Indicated on display

Scheme 363

The hydraulic pump for traction control -V156- is activated for ten (10) seconds.

1. Advance through program sequence by pressing --> button.

Indicated on display

Scheme 364

Display group 3: Activating ESP driving test

The ESP driving test is used to test the plausibility of the signals from the sensor for transverse acceleration, sender for rotation rate and pressure sensor.

The ESP driving test should be carried out after any components of the ESP system are removed or replaced.

1. Connect the VAG1551 Scan Tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .

Indicated on display

Scheme 365

1. Press buttons -0- and -4- to select "Basic Setting" function 04.

Indicated on display

Scheme 366

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 367

1. Press buttons -0-, -0- and -3-. Press -Q- button to confirm input.

Indicated on display

Scheme 368

1. The ESP driving test is activated.
2. The ABS warning light -K47- and the traction control indicator light -K86- go on.

1. Press buttons -0- and -6- to select "End Output" function 06. Press -Q- button to confirm input.

Indicated on display

Scheme 369

1. Disconnect VAG 1551 scan tool.
2. Start engine.
3. Press the brake pedal hard (brake pressure higher than 35 bar) until the traction control indicator light -K86- turns off. This completes the adjustment with the engine not running
4. Perform the following test drive: Drive around a right (left) hand curve and then around a left (right) hand curve.
5. The ABS warning light -K47- must go out. This completes the ESP driving test and the system is OK. NOTE: Always follow the rules of the road and pay attention to traffic conditions. While driving around the curves, a sender for rotation rate of around 10°/sec must be attained. A curve with a radius of 10 - 12 m and a speed of 15 - 20 km/h for around 4 sec. fulfills this requirement. The test drive must not require the use of ESP, ASR, EDL, or ABS. Other maneuvers required while driving around the curves do not influence the test.
6. If the ABS warning light -K47- does not go out, the ESP driving test was not carried out correctly.
7. If the ABS warning light -K47- does not go out and the traction control indicator light -K86- comes back on, there are malfunctions in the system. See «DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . NOTE: If the ESP driving test was interrupted, by switching off the ignition, for example, you must repeat the entire test.

Output Diagnostic Test Mode (DTM) (scan tool function 03)

The output Diagnostic Test Mode (DTM) can be used to check the function of the components that are actuated by the control module after it processes incoming signal from the sensors.

Note. Output Diagnostic Test Mode can and must only be selected once after the ignition is switched on.

These check include all functions and properties under operating conditions, for example

1. Electrically operated hydraulic valves that open and close when activated by the control module.
2. The relay of an electrical motor when activated by the control module. The motor switches on and carry outs the task.

Before initiating the output Diagnostic Test Mode (DTM), make sure there are no electrical malfunctions in the system to be tested. This will enable you to recognize any mechanical problems. Check Diagnostic Trouble Code (DTC) memory before starting the output DTM. See DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING .

The technician must be sure there are no electrical malfunctions in the system. If the technician has made sure that there are no electrical malfunctions in the system, it will be possible to identify any mechanical malfunctions in the individual actuators if the results of the output DTM are not as specified here. Replace the relevant component.

With the Bosch 5.3 ABS/ESP the output Diagnostic Test Mode (DTM) can be used to check the electrically actuated hydraulic valves and the pump motor in the hydraulic module. It is also possible to check that the brake lines going to the four wheels are connected correctly.

Note. The vehicle must be raised until all wheels are free to turn. A second technician is required to check whether the wheels are locked or can be turned. You can stop the test sequence at any time by pressing the -C- button. To avoid overloading the components being checked, they are actuated during the test sequence for a period of 60 (or 90) seconds. The output diagnostic test will be terminated if the --> button is not pressed within this period. The ABS warning light and the red brake warning symbol blink during the test. If the brake pedal is pressed repeatedly this will exhaust the vacuum in the brake booster. For this reason, the brake pedal must be pressed harder in order to achieve the same braking effect. It may be advisable to start the engine briefly to build up vacuum in the booster.

During the test, the individual test steps are shown in the second line of the VAG1551 scan tool display. The following abbreviations are used.

IV = Inlet valve

OV = Outlet valve

LF = Left-Front

RF = Right-Front

LR = Left-Rear

RR = Right-Rear

B+ = Battery Positive Voltage (B+) at valve

0V = 0 volts; No voltage at valve

Locked/free = Wheel condition; must be checked by second technician

hyd.pump = Hydraulic pump

1. Connect the VAG1551 Scan Tool and select the address word 03 "Brake Electronics" See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. Check the control module version. See «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) and press --> button.

Indicated on display

Scheme 370

1. Press buttons -0- and -3- to select "Output Diagnostic Test Mode" function 03.

Indicated on display

Scheme 371

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 372

ABS return flow pump -V39- should start running audibly.

The brake pedal can be felt to vibrate. This is because the hydraulic pump is producing pressure pulses in the brake lines, which induce the vibrations that can be felt at the pedal.

The pressure pulses in the brake lines are not sufficient to lock the wheels

Scheme 373

Illustration A01-0015 is a schematic diagram of the hydraulic circuit of an ABS/EDL system. This will give a better understanding of the various test steps in the output Diagnostic Test Mode (DTM).

1. The gray-shaded components are active.
2. Thin solid lines represent hydraulic lines or hoses that are not under pressure.
3. Thick broken lines represent hydraulic lines or hoses working as suction lines.
4. Thick solid lines represent hydraulic lines or hoses that are under pressure.

Scheme 374

1. Press --> button.

Indicated on display

Scheme 375

1. Press --> button.

Indicated on display

Scheme 376

When the brake pedal is pressed, brake fluid pressure will be built up in all four calipers. All four wheels will be locked.

This indicates that the mechanical and hydraulic components of the brake system are working properly, which means that the master cylinder is able to build up pressure in all four calipers and there are no leaks in the hydraulic lines, hoses, and connections.

Scheme 377

If the wheels do not lock, visually inspect brake fluid reservoir, master brake cylinder, hydraulic unit, and calipers.

Concentrate on the left-front wheel first. The function of the control elements for this wheel is tested first.

Scheme 378

Note. This test step in the output diagnostic test mode corresponds to the "pressure build-up" phase during ABS-controlled braking.

1. Press --> button.

Indicated on display

Scheme 379

Keep pressing brake pedal.

The inlet valve is activated, which interrupts the brake line. However, the fluid pressure is still maintained in the caliper. The left-front wheel remains locked.

Note. This test step in the output diagnostic test mode corresponds to the "maintain pressure" phase during ABS-controlled braking.

1. Press --> button.

Indicated on display

Scheme 380

Keep pressing brake pedal. The inlet valve and the outlet valve for the left-front wheel are activated. The hydraulic pump starts running and reduces the fluid pressure in the caliper via the open outlet valve.

The brake pedal must not give, and should press harder against foot.

You should now be able to turn the left-front wheel.

Scheme 381

If you cannot turn the wheel, check whether the brake line for the left-front wheels is connected correctly.

If yes, this indicates a mechanical malfunction in one of the valves, providing there is no electrical malfunction in the system. Replace hydraulic control module.

If the pedal gives under foot, this means that the inlet valve or the check valve activated in parallel to the inlet valve is leaking. Replace hydraulic control module.

Note. This test step in the output diagnostic test mode corresponds to the "pressure reduction" phase during ABS-controlled braking.

Scheme 382

1. Press --> button.

Indicated on display

Scheme 383

ABS return flow pump -V39- will stop running.

Keep pressing brake pedal. Only the inlet valve is still activated and interrupts the brake line. If the inlet valve is not leaking, it should be possible to turn the left-front wheel.

If you cannot turn the wheel, this means that the inlet valve or the check valve activated in parallel to the inlet valve is leaking. Replace hydraulic control module.

Scheme 384

1. Press --> button.

Indicated on display

Scheme 385

Keep pressing brake pedal. The inlet valve is no longer activated and does not interrupt the brake line. The brake pedal will give perceptibly under foot. Fluid pressure is built again in the left-front caliper. The wheel will be locked.

Scheme 386

1. Press --> button.

Indicated on display

Scheme 387

1. Press --> button.

Continue the output diagnostic test mode in order to check the right-front, left-rear, and right-rear wheels in turn. The test steps are the same as for the left-front wheel, so they are not described in detail.

Indicated on display

Scheme 388

1. Press --> button.

Indicated on display

Scheme 389

1. Press --> button.

Indicated on display

Scheme 390

1. Press --> button.

ABS return flow pump -V39- should start running.

The brake pedal must not give.

Indicated on display

Scheme 391

1. Press --> button.

ABS return flow pump -V39- will stop running.

Indicated on display

Scheme 392

1. Press --> button.

The brake pedal will give perceptibly under foot.

Indicated on display

Scheme 393

1. Press --> button.

Indicated on display

Scheme 394

1. Press --> button.

Indicated on display

Scheme 395

1. Press --> button.

Indicated on display

Scheme 396

1. Press --> button.

Indicated on display

Scheme 397

1. Press --> button.

ABS return flow pump -V39- should start running.

The brake pedal must not give.

Indicated on display

Scheme 398

1. Press --> button.

ABS return flow pump -V39- will stop running.

Indicated on display

Scheme 399

1. Press --> button.

The brake pedal will give perceptibly under foot.

Indicated on display

Scheme 400

1. Press --> button.

Indicated on display

Scheme 401

1. Press --> button.

Indicated on display

Scheme 402

1. Press --> button.

Indicated on display

Scheme 403

1. Press --> button.

Indicated on display

Scheme 404

1. Press --> button.

ABS return flow pump -V39- should start running.

The brake pedal must not give.

Indicated on display

Scheme 405

1. Press --> button.

ABS return flow pump -V39- will stop running.

Indicated on display

Scheme 406

1. Press --> button.

The brake pedal will give perceptibly under foot.

Indicated on display

Scheme 407

1. Press --> button.

Indicated on display

Scheme 408

1. Press --> button.

Indicated on display

Scheme 409

The EDL change-over valve (left) and the EDL inlet valve are activated. ABS return flow pump -V39- runs for one second. The pump draws brake fluid out of the fluid reservoir via the EDL inlet valve and builds up pressure in the EDL-controlled calipers. These wheels will then be locked.

If not, this indicates a mechanical malfunction in one of the valves, providing there is no electrical malfunction in the system. Replace hydraulic control module.

Scheme 410

1. Press --> button.

Indicated on display

Scheme 411

Note. The output diagnostic test mode is completed. The ABS warning light and the red warning symbol for brake system go out.

1. Press --> button.

Indicated on display

Scheme 412

Note. If the ABS warning light does not go out, this indicates a malfunction in the system. Follow the procedure in SAFETY MEASURES AND TROUBLESHOOTING BASICS exactly.

1. Press buttons -0- and -6- to select "End Output" function 06. Press -Q- button to confirm input.

Code Control Module (scan tool function 07)

Coding the ESP control module adapts the control module to the vehicle.

New control modules from the parts distribution center are un-coded and must be coded after being installed.

Coding is only possible if a dealership number is stored in the VAG1551 scan tool.

Before the control module can be coded, "Login Procedure" function 11 must have been successfully carried out using the VAG1551/1552 scan tool. See LOGIN PROCEDURE (SCAN TOOL FUNCTION 11) .

After the control module is coded, the steering angle sensor -G85- must be zeroed without leaving "Basic Setting" function 04, display group 001. See BASIC SETTING (SCAN TOOL FUNCTION 04) .

Note. If the control module is coded with code 00000 or with a code that does not match the vehicle, the ABS warning light -K47- and the traction control indicator light -K86- light continuously, and the DTC01044 - "Control module incorrectly coded" is stored in the DTC memory of the control module.

Scheme 413

Scheme 414

1. Determine type of brake caliper installed on front axle of vehicle. The illustration shows the brake type FN3 made by Teves/Ate (recognized by: clip on brake pad carrier). The illustration shows the brake type HP2 made by Lucas (recognized by: double-piston brake caliper).
2. Connect VAS5051 tester or VAG1551 scan tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .

Indicated on display

Scheme 415

1. Press buttons -1- and -1- to select "Login Procedure" function 11.

Indicated on display

Scheme 416

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 417

1. Enter code according to the following table and press -Q- button to confirm input. LOGIN CODE - BOSCH 5.3 WITH ESP Type of brake caliper on front axle Login code FN3 Teves/Ate 05397 HP2 double-piston brake caliper 05497

Indicated on display

Scheme 418

1. Press -0- and -7- buttons to select "Code Control Module" function 07 and press -Q- button to confirm input.

Indicated on display

Scheme 419

1. Confirm input using the -Q- button.

Indicated on display

Scheme 420

1. Enter code according to the following table and press -Q- button to confirm input. CONTROL MODULE CODE - BOSCH 5.3 WITH ESP Type of brake caliper on front axle Coding FN3 Teves/Ate 08297 HP-2 double-piston or Brembo caliper 08397

VAG1551 scan tool display indicates control module coding, for example: 4D0 907 379 D ABS/EPS front.

Scheme 421

1. Press --> button.

Indicated on display

Scheme 422

1. Press -0- and -4- buttons to select "Basic Setting" function 04 and press -Q- button to confirm, to start zeroing procedure for steering angle sensor -G85-, display group 001, see «BASIC SETTING (SCAN TOOL FUNCTION 04)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__basic-setting-scan-tool-function-04) .

Note. If the control module is coded with code 00000 or with a code that does not match the vehicle, the ABS warning light -K47- and the traction control indicator light -K86- light continuously, and the DTC01044 - "Control module incorrectly coded" is stored in the DTC memory of the control module.

Measuring Value Block (scan tool function 08), reading

The control module can transfer measuring values to the VAS5051 tester and VAG1551 scan tool. These measured values provide information about the operational status of the system and the sensors connected to it. In many cases the data supplied can be used to troubleshoot and repair malfunctions. The measured values provided by ESP are accessible in six display groups, which can be called up according to their display group numbers.

1. Connect VAS5051 tester or VAG1551 scan tool and select the address word 03 "Brake Electronics". See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) . NOTE: When the printer is switched on, the contents of the display will be printed out on the scan tool log. When reading the measuring value block, also check wiring and connectors for loose terminals.
2. Check the control module version. See «CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__control-module-versions-scan-tool-function) and press --> button.

Indicated on display

Scheme 423

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.

Indicated on display

Scheme 424

1. Press the -Q- button to confirm input.

Indicated on display

Scheme 425

1. Press buttons -0-, -0- and -1-.
2. Press the -Q- button to confirm input.

Test table: display group 1 (001)

Note. Display fields 1 to 4 show the actual wheel speeds in km/h. These are calculated by the ABS Control Module (w/EDL) - J104- on the basis of the signals received from the wheel speed sensors. If one of the display fields shows no reading, proceed as for DTCs 00283, 00285, 00287, 00290 "ABS Wheel Speed Sensor". See DTC TABLE; DTCS 00000 TO 00526 . In order to check that the wheel speed sensor signals are correctly assigned to the four wheels, the vehicle must be raised. On vehicles with manual transmission put the gear shift lever in neutral. On vehicles with automatic transmission move the selector lever to position "N." Turn the relevant wheel by hand, and at the same time prevent the other wheels from rotating. When the vehicle is accelerated uniformly on a dry surface, the displayed value will increase continuously in rising whole numbers (e.g. 6 km/h, km/h, 8 km/h...). The difference between displayed values 1-4 should not be more than +/-1 km/h (error from out-of-round wheels). If the values jump, for instance from ... 6km/h, 7 km/h to 12 km/h... or if the difference between the displayed values is greater than +/-1 km/h, then check the installation of the wheel speed sensors and rotors.

See SUSPENSION - FRONT or SUSPENSION - REAR .

Scheme 426

1) OBD is terminated by ABS Control Module (w/EDL) -J104- if road speed exceeds 19 km/jh (12 MPH). 1 Km/h is the minimum speed that can be displayed (at 0 Km/h, for example, the tester, displays 1 Km/h).

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons "UP" and "DOWN" on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 427

1. Press buttons -0-, -0- and -2-.
2. Press the -Q- button to confirm input.

Scheme 428

1. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For the DTC table, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons "UP" and "DOWN" on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 429

1. Press buttons -0-, -0- and -3-.
2. Press the -Q- button to confirm input.

Note for display group 3 (003)

If you want to read the display fields engine speed and actual engine torque with the engine running, you must end the communication between the scan tool and the control module by selecting the "End Output" function. See END OUTPUT . Start the engine and re-initiate communication between the scan tool and the control module.

Indicated on display

Scheme 430

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.
2. Press the -Q- button to confirm input.

Indicated on display

Scheme 431

1. Press buttons -0-, -0- and -3-.
2. Press the -Q- button to confirm input.

Scheme 432

1. For the DTC table, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Note. OBD is terminated by ABS Control Module (w/EDL) -J104- if road speed exceeds 19 km/h (12 MPH). The actual engine speed (RPM) is calculated by subtracting the dissipation torque from the engine torque.

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons "UP" and "DOWN" on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 433

1. Press buttons -0-, -0- and -4-.
2. Press the -Q- button to confirm input.

Scheme 434

1. For more information about the EDL, see «EDL»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For the DTC chart, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Note. OBD is terminated by ABS Control Module (w/EDL) -J104- if road speed exceeds 19 km/h (12 MPH).

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons "UP" and "DOWN" on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 435

1. Press buttons -0-, -0- and -5-.
2. Press the -Q- button to confirm input.

Note for display group 5 (005)

To read the display fields sender for rotation rate and transverse acceleration while the vehicle is moving, use the "End Output" function (see END OUTPUT ) to end the communication between the scan tool and the control module. Start the engine and re-initiate communication between the scan tool and the control module.

Indicated on display

Scheme 436

1. Press buttons -0- and -8- to select "Read Measuring Value Block" function 08.
2. Press the -Q- button to confirm input.

Indicated on display

Scheme 437

1. Press buttons -0-, -0- and -5-.
2. Press the -Q- button to confirm input.

Scheme 438

1. For another check of the sensor (Scheme 445)

Note. OBD is terminated by ABS Control Module (w/EDL) -J104- if road speed exceeds 19 km/h (12 MPH).

1. If nothing is displayed, press -C- button, select function 02 and check DTC memory. Repair the malfunction with the help of the DTC table. See «DIAGNOSTIC TROUBLE CODE (DTC) MEMORY (SCAN TOOL FUNCTION 02), CHECKING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .

Note. Sensor for transverse acceleration -G200- is very sensitive to shocks. If sensor is dropped, do not reinstall it in vehicle. Instead, use a new sensor.

Scheme 439

Sensor must be removed to be tested. The sensor for transverse acceleration -G200- is installed under the driver's seat.

Scheme 440

Leave the sensor connected and turn it 90° along its longitudinal axis.

Using display group 5 (005) of the "Read Measuring Value Block" function, a value of -9.8 +/- 1 m/s 2 or + 9.8 +/- 1 m/s 2 can be read on the scan tool display.

A plus in front of the number indicates the affect on the sensor while driving around a left-hand curve.

A minus in front of the number indicates the affect on the sensor while driving around a right-hand curve.

After reinstalling the sensor for transverse acceleration -G200- tighten the bolts to 5 Nm.

Note. Due to an error in the test card 8.0 for the VAG1551 scan tool and the test card 5.0 for the VAG1552 scan tool, the display for Measuring Value Block 5, display group 4 is offset by one decimal point. This means that a transverse acceleration value of 9.81m/s 2 is displayed as 0.98 m/s 2 .

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons => and => on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 441

1. Press buttons -0-, -0- and -6-.
2. Press the -Q- button to confirm input.

Scheme 442

1. For electrical testing, see «ELECTRICAL TESTING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. For "Login Procedure", see «LOGIN PROCEDURE (SCAN TOOL FUNCTION 11)»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__login-procedure-scan-tool-function-11) .

Note. The display group numbers can be selected in sequence by pressing buttons <-1 and 3-> on the VAG1551 scan tool, arrow buttons "UP" and "DOWN" on the VAG1552 scan tool, or the arrow buttons => and => on the screen of the VAS5051 tester.

1. Press -C- button to input display group number manually.

Indicated on display

Scheme 443

1. Press buttons -0-, -0- and -5-.
2. Press the -Q- button to confirm input.

Scheme 444

Note. OBD is terminated by ABS Control Module (w/EDL) -J104- if road speed exceeds 19 km/h (12 MPH).

1. If the On Board Diagnostic (OBD) sequence does not provide any indication of the source of the malfunction, work through all of the electrical test steps.
2. If the OBD sequence identifies the source of the malfunction, only carry out the test steps recommended in the DTC table (specific testing).

1. "Automatic Test Sequence" carried out to establish that any malfunctions stored in Transmission Control Module (TCM) and Engine Control Module (ECM) only affect ABS/ESP.

Scheme 445

1. Connect VAS5051 tester or VAG1551 scan tool and select the address word 00 (with ignition on). See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
2. After completing electrical testing, check and erase DTC memories of Transmission Control Module (TCM) and Engine Control Module (ECM). Multi-pin harness connector for ABS Control Module (w/EDL) -J104- in proper condition, with no bent, broken or corroded terminals. Replace any damaged terminals using VAS1978 wiring repair kit. NOTE: The instruction manual for the VAS1978 wiring harness repair kit generally forbids the repair of any lines in the ABS or related systems. This rule only pertains to the shielded lines in these systems. Ignition and electrical consumers switched off before beginning testing (headlights, lighting, fan, etc.). For steps 13 through 16, raise the vehicle until the wheels rotate freely. On vehicles with manual transmission put the gear shift lever in neutral. On vehicles with automatic transmission move the selector lever to position "N."

Special tools and equipment required

1. VAS5051 tester or VAG1551 scan tool or VAG1552 scan tool
2. VAG1598/20 test box
3. Connector test kit VAG1594
4. Multimeter (Fluke 83 or equivalent)
5. Pressure gauge VAG1310A

Connecting VAG1598/20 test box and checking ESP system

Scheme 446

1. Switch ignition off.
2. Remove ABS Control Module (w/EDL) -J104-. See «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .
3. Disconnect multi-pin connector from ABS Control Module (w/EDL) -J104-.
4. Check multi-pin connector between harness connector and ABS Control Module (w/EDL) -J104-. The socket designations on the VAG1598/20 test box are identical to the terminal designations on the ABS Control Module (w/EDL) -J104- and on the wiring harness connector.
5. Connect VAG1598/20 test box to multi-pin connector of wiring harness.

Scheme 447

Scheme 448

Scheme 449

Scheme 450

Scheme 451

Scheme 452

Scheme 453

Scheme 454

Scheme 455

1. For wiring diagrams, see appropriate System Wiring Diagrams article.

Electrical test table

1. The socket designations of the VAG1598 test box are identical to the terminal designations of the ABS Control Module (w/EDL) -J104- in the wiring diagram. Incorrect test procedures can cause damage to the system. Do not make connections between any terminals other than those listed in the table. See appropriate System Wiring Diagrams article.
2. The specified values refer to the readings on the multimeter and are not necessarily applicable for other test units.
3. If the measured values do not match the specifications, refer to the corrective actions on the right side of the table.
4. If the measured values match the specifications, also check wiring for intermittent loose terminals and short circuit to B+ and Ground (GND). This applies especially to sporadic malfunctions.
5. Use the VAG1594 connector kit for checking continuity (bridging leads).
6. If the measured values only differ slightly from the specifications, clean the sockets and harness connectors of the testers and adapter leads (with terminal spray G 000 700 04), and repeat the check. Before replacing components, check the wiring and connections again, particularly if the specification calls for a resistance reading of less than 10 ohm..

Scheme 456

Scheme 457

Scheme 458

Scheme 459

Scheme 460

Scheme 461

Scheme 462

Scheme 463

Scheme 464

Scheme 465

Scheme 466

Scheme 467

Scheme 468

1. For the DTC table, see «DTC TABLE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)

Scheme 469

Scheme 470

Scheme 471

1. For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03).

Scheme 472

Scheme 473

1. For brake fluids and bleeding, see «BLEEDING BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/mechanical-hydraulic/#disc-brakes) .
2. For information about connecting the VAG 1551 scan tool, see «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and)

Scheme 474

Scheme 475

Scheme 476

1. For instrument cluster information, see «INSTRUMENTS»(ref-196896) (1997-99), or «INSTRUMENTS»(/audi/a8/d3-2002-2005/remont/gauges-instrument-panels/#instruments) (2000-03).

Scheme 477

Scheme 478

Scheme 479

Scheme 480

Scheme 481

Scheme 482

Scheme 483

Scheme 484

Scheme 485

Continuation

Scheme 486

Scheme 487

Scheme 488

Scheme 489

Scheme 490

Scheme 491

Continuation

Scheme 492

1. For anti-lock brake components and information, see «ANTILOCK BRAKE SYSTEM»(/audi/a8/d3-2002-2005/remont/anti-locktraction-control/#antilock-brake-system) .

Safety precautions

Note the following points if testers and measuring instruments have to be used during a test drive

To prevent injuries to persons and/or damage to the fuel injection and ignition system, the following must be noted

1. Always switch off the ignition before connecting or disconnecting measuring instruments and testers.
2. In the case of some tests, a DTC may be recognized and stored by the control module. At the end of all tests and repairs, the DTC memory should be checked and, if necessary, erased. CAUTION: On vehicles equipped with Audi Telematics by OnStar(R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting the vehicle battery. See «EXAMPLE: SWITCH OFF EMERGENCY (BACK-UP) BATTERY»(/audi/a8/d3-2002-2005/remont/communication-devices/#on-board-diagnostic-obd-radio-navigation-steering-telematics__example-switch-off-emergency-back-up-battery) . Switch-on the emergency (back-up) battery after reconnecting the vehicle battery. See «EXAMPLE: SWITCH ON EMERGENCY (BACK-UP) BATTERY»(/audi/a8/d3-2002-2005/remont/communication-devices/#on-board-diagnostic-obd-radio-navigation-steering-telematics__example-switch-on-emergency-back-up-battery) .
3. Always switch off the ignition before connecting or disconnecting the battery, otherwise the engine control module may be damaged.

1. Use wiring diagram to check that fuses are OK.
2. Connect the vehicle diagnosis, measurement and information system VAS 5051 or Scan tool V.A.G 1551. See «VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__vag1551-scan-tool-st-connecting-and) .
3. Switch ignition on.

1. Switch on printer with the Print button (indicator light in button lights up).
2. Press button -1- for "Rapid data transfer" mode.

Indicated on display

Scheme 493

Address word for tire pressure monitoring: 65

1. Press buttons -6- and -5-.

Indicated on display

Scheme 494

Scheme 495

1. Confirm entry with -Q- button.
2. The display will indicate the following after approximately 5 seconds: 4D0907273: Part number Tire press. monit.: Component designation D105: Software version of control module Coding 20129: Control module code WSC 06812: Workshop code NOTE: Check coding according to coding table. (Scheme 528)
3. Press --> button.

Indicated on display

Scheme 496

1. Press HELP button to obtain a printout of the available functions.
2. Continue through program procedure using the --> button.

On Board Diagnostic (OBD) functions

The following functions are possible

01 - Checking control module version, see CHECK CONTROL MODULE VERSION .

02 - Checking DTC memory, see CHECK DTC MEMORY .

05 - Erase DTC memory, see ERASE DTC MEMORY .

06 - End output, see CAN-BUS, FUNCTION .

07 - Encoding control module, see ENCODE CONTROL MODULE .

08 - Read measured value block, see READ MEASURED VALUE BLOCK .

10 - Adaptation, see ADAPTATION .

Indicated on display

Scheme 497

1. Press buttons -0- and -1- (01 selects "Check control module version" function).

Indicated on display

Scheme 498

Scheme 499

1. Confirm entry with -Q- button.
2. The display will indicate the following after approximately 5 seconds: 4D0907273: Part number Tire press. monit.: Component designation D105: Software version of control module Coding 20129: Control module code WSC 06812: Workshop code
3. Press --> button.

Note. The displayed DTC information is not constantly updated but only when initiating On Board Diagnostic (OBD) or with function 05 "Erase DTC memory".

1. Switch on printer with the Print button (indicator light in button lights up).

Indicated on display

Scheme 500

1. Press buttons -0- and -2- (02 selects the function "Check DTC memory".)

Indicated on display

Scheme 501

Scheme 502

Scheme 503

1. Confirm entry with -Q- button. The number of DTCs stored appears on the display. The stored DTCs are displayed and printed one after the other.
2. Check printout against DTC table and repair all DTCs as necessary. See «DTC TABLE FOR TIRE PRESSURE MONITORING»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr__dtc-table-for-tire-pressure-monitoring) . The display "No DTC recognized" causes program to return to original setting after pressing the --> button.

Indicated on display

Scheme 504

If something else is displayed

See Scan tool operating instructions

1. End output (function 06). See «CAN-BUS, FUNCTION»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
2. Switch off ignition and detach diagnostic connector.

DTC table for tire pressure monitoring

Note. The following table lists all DTCs that can be recognized by the control module and printed out by the V.A.G 1551. The DTCs are listed in order according to their 5-figure code numbers. DTCs appear only on print-out. Before replacing a component shown as faulty, check wiring and connections to component as well as ground connections according to current flow diagram. After completing repair and checking function of system, always check DTC memory once again with Scan tool V.A.G 1551 and erase memory. The DTC memory records all static and sporadic DTCs. If a malfunction occurs and persists for at least 2 seconds, it is identified as a static malfunction. If malfunction does not occur again it is registered as a sporadic malfunction. "ISP" appears on the right of the display. When ignition is switched on, all existing DTCs are automatically reclassified as sporadic DTCs and will only register as static DTCs if they still occur after testing. Sporadic DTCs which no longer occur after 50 driving cycles (ignition on for at least 5 minutes, road speed of 30 km/h) are erased automatically.

Scheme 505

Scheme 506

Scheme 507

Scheme 508

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 509

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 510

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 511

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 512

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 513

1. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .

Scheme 514

1. For more battery information, see «BATTERY DISCONNECT PRECAUTIONS»(/audi/a8/d3-2002-2005/remont/charging-system/#generators-regulators) .
2. For "read measured value block" and related information, see «READ MEASURED VALUE BLOCK»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. To replace faulty tire pressure sensor or antenna, see «WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM»(/audi/a8/d3-2002-2005/remont/warning-system/#wheels-tires-tire-pressure-control-system) .
4. For more information about encoding the control module, see «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr)
5. For instrument cluster diagnostic information, see «ON BOARD DIAGNOSTIC (OBD)»(ref-196894) (1997-99), or «ON BOARD DIAGNOSTIC (OBD)»(/audi/a8/d3-2002-2005/remont/collisionavoidance/#on-board-diagnostic-obd) (2000-03).

This function is used to encode the control module for the following features

1. Manufacturer
2. Configuration
3. Specified pressure, partially laden

Note. The coding table only lists possible combinations that apply to the Audi A8.

Performing coding

Indicated on display

Scheme 515

1. Press buttons -0- and -7- (The function "Code control module" is selected with 07).

Indicated on display

Scheme 516

1. Confirm input with -Q- button.

Indicated on display

Scheme 517

1. Enter the appropriate code number using the coding table (Scheme 528)

Code: 20129

1. Manufacturer: 2 = Audi
2. 2nd digit = 0
3. Configuration: 1 = 4 antennas, 5 wheels, 4-wheel-monitoring
4. Specified pressure: 2 = 2.2 bar
5. 5th digit = 9

Scheme 518

1. The display shows the control module identification with the entered code (20129).
2. Press --> button to terminate coding.

Indicated on display

Scheme 519

1. Press buttons -0- and -6

Indicated on display

Scheme 520

Scheme 521

Scheme 522

1. Confirm entry with -Q- button.
2. The display shows the control module identification with the entered code (20129).
3. Press --> button to terminate coding.

Indicated on display

Scheme 523

1. Press buttons -0- and -6-.

Indicated on display

Scheme 524

1. Confirm entry with -Q- button.

Performing function "Read measured value block"

Indicated on display

Scheme 525

1. Press buttons -0- and -8- (08 selects function "Read measured value block").

Indicated on display

Scheme 526

1. Confirm entry with -Q- button.

Indicated on display

Scheme 527

1. Enter display group number and confirm with -Q- button.

The measured value block which has been selected will appear in standard format.

Scheme 528

Scheme 529

Scheme 530

Scheme 531

Scheme 532

Scheme 533

Scheme 534

Scheme 535

Scheme 536

Scheme 537

Scheme 538

Scheme 539

Scheme 540

Scheme 541

Scheme 542

Scheme 543

Scheme 544

Scheme 545

Adaptation

The antenna diagnosis can be activated with the "Adaptation" function.

TIRE PRESSURE MONITOR ADAPTATION FUNCTION

Performing Adaptation (function 10)

Indicated on display

Scheme 546

1. Press buttons -1- and -0- (10 selects function: "Adaptation").

Indicated on display

Scheme 547

1. Confirm entry with -Q- button.

Indicated on display

Scheme 548

1. Enter the required Adaptation channel 17.
2. Confirm entry with -Q- button.

Indicated on display

Scheme 549

1. Press --> button.

Indicated on display

Scheme 550

1. Entry via buttonpad: 0001

Indicated on display

Scheme 551

1. Confirm entry with -Q- button.

Indicated on display

Scheme 552

1. Confirm entry with -Q- button.

Indicated on display

Scheme 553

1. Press --> button.

Channel 17 should now display

Indicated on display

Scheme 554

1. Press --> button.

Measured value block 021 should now display

Indicated on display

Scheme 555

If the antenna diagnosis is completed

Indicated on display

Scheme 556

1. Press --> button.
2. Read out the DTC memory, see «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
3. Press buttons -0- and -6- (06 selects the function "End output").

Indicated on display

Scheme 557

Tire pressure monitoring system, operating for the first time

The tire pressure monitoring system needs to be restarted after the control module has been replaced or if DTC "01487" occurs.

1. First check whether the instrument cluster is correctly adapted. Measured value block 130 must show a "1" in display zone 1.

If there is no entry

1. Perform corresponding Adaptation of the instrument cluster. See «ADAPTATION (SCAN TOOL FUNCTION 10)»(ref-196894-S37463265152005101000000) (1997-99) or «ADAPTATION (FUNCTION 10)»(/audi/a8/d3-2002-2005/remont/collisionavoidance/#on-board-diagnostic-obd__adaptation-function-10) (2000-03).
2. Switch the ignition off and back on again once.
3. Encode the control module for tire pressure monitoring. See «ENCODE CONTROL MODULE»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) .
4. Read out and erase the DTC memory. See «CHECK DTC MEMORY»(/audi/a8/d3-2002-2005/remont/warning-system/#on-board-diagnostic-obd-absedlasr) . All wheels must have the correct tire pressure.
5. If necessary fill the tires.
6. Following the owner's manual, go to the "Settings" menu, save the tire pressure in "Save pressures" and click on the menu item to confirm.
7. Switch the ignition off and back on again once.
8. There must not be any DTC entries in either the DTC memory of the instrument cluster or the DTC memory of the control module for tire pressure monitoring.

If DTCs are stored

1. Repair malfunction. For model years 1997-1999, see «ON BOARD DIAGNOSTIC (OBD)»(ref-196894) . For model years 2000 and up, see «ON BOARD DIAGNOSTIC (OBD)»(/audi/a8/d3-2002-2005/remont/collisionavoidance/#on-board-diagnostic-obd) .
2. Perform a test drive (for at least 20 minutes).
3. Switch the ignition off and back on again once.
4. Measured value block 001 should now show the value "FL wheel" in display zone 1.

See also:
• EXAMPLE: SWITCH OFF EMERGENCY (BACK-UP) BATTERY
• EXAMPLE: SWITCH ON EMERGENCY (BACK-UP) BATTERY
• BLEEDING BRAKE SYSTEM
• SUSPENSION - FRONT
• SUSPENSION - REAR
• ANTILOCK BRAKE SYSTEM
• INSTRUMENTS
• STEERING
• SPECIFICATIONS & PROCEDURES
• ON BOARD DIAGNOSTIC (OBD)
• STEERING ANGLE SENSOR -G85-, REMOVING AND INSTALLING
• WHEEL ALIGNMENT PROCEDURES
• WHEELS, TIRES - TIRE PRESSURE CONTROL SYSTEM
• BATTERY DISCONNECT PRECAUTIONS
• ON BOARD DIAGNOSTIC (OBD)
• ADAPTATION (FUNCTION 10)
• VAG1551 SCAN TOOL (ST), CONNECTING AND ENTERING ADDRESS WORD
• SELECTING FUNCTIONS
• ERASE DTC MEMORY
• TABLE OF WARNING LIGHT FUNCTIONS
• TEST REQUIREMENTS
• CHECK CONTROL MODULE VERSION
• CHECK DTC MEMORY
• ROAD TEST
• ENCODE CONTROL MODULE
• READ MEASURED VALUE BLOCK
• ELECTRICAL TESTING
• FUNCTION
• TEST TABLE, DISPLAY GROUP 1
• TEST TABLE, DISPLAY GROUP 2
• TEST TABLE, DISPLAY GROUP 3
• END OUTPUT
• DTC TABLE
• OUTPUT DIAGNOSTIC TEST MODE (DTM)
• FUNCTION OF BOSCH ABS 5.3 SERIES
• INDICATOR LIGHT FUNCTIONS, OVERVIEW
• TEST CONDITIONS
• CONTROL MODULE VERSIONS (SCAN TOOL FUNCTION 01), CHECKING
• TEST DRIVE
• RECONNECTING BATTERY, PROCEDURES
• MEASURING VALUE BLOCK (SCAN TOOL FUNCTION 08), READING
• BASIC SETTING (SCAN TOOL FUNCTION 04)
• OUTPUT DIAGNOSTIC TEST MODE (DTM) (SCAN TOOL FUNCTION 03)
• CODE CONTROL MODULE (SCAN TOOL FUNCTION 07)
• LOGIN PROCEDURE (SCAN TOOL FUNCTION 11)
• ESP FUNCTION
• DISPLAY GROUP 1: ZEROING THE STEERING ANGLE SENSOR -G85-.
• DISPLAY GROUP 2: ACTIVATING HYDRAULIC PUMP FOR TRACTION CONTROL -V156
• DISPLAY GROUP 3: ACTIVATING ESP DRIVING TEST
• SAFETY MEASURES AND TROUBLESHOOTING BASICS
• ADAPTATION
• DTC TABLE FOR TIRE PRESSURE MONITORING