On Board Diagnostic - System Description - Exterior Lamps (sedan) Audi A4 B8

GENERAL INFORMATION AND TECHNICAL DATA

The headlamps, the tail lamps and the and the lamps in the exterior mirrors work as a network.

COMPONENTS

GENERAL INFORMATION AND COMPONENTS

This function possible only if the vehicle has a rain/light recognition sensor and the headlamp switch is set to AUTO.

The following components are included in this function

1. Vehicle Electrical System Control Module -J519
2. Rain/Light Recognition Sensor -G397
3. Headlamp Switch -E1
4. Comfort System Central Control Module -J393
5. Steering Column Electronic Systems Control Module -J527
6. Windshield Wiper/Washer Intermittent Switch -E22
7. Tail Lamps
8. Headlamps

FUNCTION DESCRIPTION

Function Requirement

1 - Switching on based on the ambient light

The rain/light recognition sensor -G397- sends the ambient light information to the vehicle electrical system control module -J519- via the LIN data bus.

The follow criteria must be met in order for the rain/light recognition sensor to work correctly

1. The glass near the sensor must be clean.
2. The coding in the rain/light recognition sensor must be adapted to the glass.

The lamps could switch on too early or too late if the working range for the rain/light recognition sensor is set incorrectly.

If the brightness limit is not met, then the data bus tells the vehicle electrical system control module to switch on the headlamps.

The comfort system central control module -J393- switches on the tail lamps and the vehicle electrical system control module switches on the headlamps. The illumination for the instrument cluster and the switches will also be switched on.

Scheme 146

2 - Switching on via the rain recognition sensor

The low beams will switch on after a predetermined number of wipe cycles (rain/light recognition sensor). The number of wipe cycles depends on the ambient light.

The comfort system central control module switches on the tail lamps and the vehicle electrical system control module switches on the headlamps.

The rain/light recognition sensor switches off automatically if the wipers do not move for a specific amount of time. On this case the illumination for the instrument cluster and the switches will not switch on.

3 - Switching on via the fog lamps

Whenever the fog lamp button is pressed, the low beam headlamps turn on if the switch is set to AUTO. This will happen regardless of the amount of darkness the rain/light recognition sensor senses. It is only possible to switch off the low beams by turning the ignition on or off.

SERVICE INFORMATION

It is very important to make sure the rain/light recognition sensor -G397- is installed correctly if a windshield is being replaced. The coding in the rain/light recognition sensor must be changed if a different type of windshield is being installed.

The low beams will switch on for reasons of safety even if the rain/light recognition sensor is faulty and the headlamp switch -E1- is set to AUTO.

The driver can set the sensitivity of the rain/light recognition sensor via the CAR menu in the MMI. It is possible to set the switch-on point in the exterior lamps menu. There are three possible settings: early, central and late.

The high beam assistant makes it possible for the high beams to switch on and off based on the traffic and the ambient conditions. This prevents glare for the other motorists as well as unnecessary use of the high beams.

This function is possible only if the vehicle has a rain/light recognition sensor and an automatic high beam control module.

The automatic high beam switch-on includes the following components

1. Headlamp Switch -E1
2. Turn Signal Switch -E2
3. Rain/Light Recognition Sensor -G397
4. Instrument Cluster Control Module -J285
5. Vehicle Electrical System Control Module -J519
6. Steering Column Electronic Systems Control Module -J527
7. Data Bus On Board Diagnostic Interface -J533
8. Automatic High Beam Control Module -J844 - with a camera with CMOS images sensors
9. Left High Beam Headlamp -M30- and Right High Beam Headlamp -M32- (Halogen)
10. Left Low Beam Reflector Motor -V294- and Right Low Beam Reflector Motor -V295- (Bi-Xenon)

Activating

To activate the high beam assistant, set the headlamp switch -E1- to AUTO and then push the turn signal switch -E2- one time to the front. The steering column electronic systems control module -J527- recognizes the position of the turn signal switch and sends the message to the vehicle electrical system control module -J519- via the CAN Bus Comfort.

The headlamp symbol in the instrument cluster will illuminate with an "A" to let the driver know the high beam assistant is on. When the high beams are on, the blue high beam symbol also comes on.

Functionality

The base of the interior rearview mirror has a camera with CMOS images sensors, which also switch on and off the low beam and the high beam. The electronics, automatic high beam control module, are integrated in the automatic dimming interior rearview mirror.

The CMOS camera takes a white and red picture of the actual traffic and ambient conditions. The automatic high beam control module evaluates the information and switches the high beams on or off.

If passing or approaching vehicles are recognized, the CAN Bus sends the request to the vehicle electrical system control module to switch off the high beam. A request to switch off will also be sent if a specific minimum vehicle speed is not reach or if the ambient brightness exceeds a set limit because of the daylight or bright street illumination. If there are no switch off conditions present, then a switch off request will be sent.

The vehicle electrical system control module controls the bulbs for the left and right high beam headlamps as well as the left and right low beam reflector motors based on the high beam recommendation sent from the automatic high beam control module when the automatic high beam switch-on is activated and the vehicle road speed exceeds a defined value and the vehicle electrical system control module simultaneously gives the command to the rain/light recognition sensor to switch on.

If the rain/light recognition sensor does not send the switch-off command, then the high beams are not controlled. If the high beams were switched off by the high beam assistant, and if the rain/light recognition sensor sends the command to switch off the low beams then the high beam is no longer controlled.

The driver can then.ly switch the high beams on or off.

If the automatic high beam control module sends a switch-off command, the driver can switch the high beams back on by pushing the turn signal switch forward one time. The high beam assistant is now temporarily deactivated. Pushing the turn signal switch forward one more time will activate the high beam assistant again. If the driver pulls the turn signal switch after the temporary deactivation, the high beams will be switched off and the high beam assistant remains deactivated.

If the high beam assistant switches on the high beams, the driver can switch them off by pulling the turn signal switch one time. The high beam assistant will remain deactivated. If the driver pushes the turn signal switch forward one time when the high beams are on, then the high beam assistant will be deactivated temporarily and the high beams remain on. When the turn signal switch is pushed again, the automatic high beam is activated. If the turn signal switch is pulled once again after it was temporarily deactivated, then the high beam assistant is deactivated permanently.

Scheme 147

1. E1 - Headlamp Switch
2. E2 - Turn Signal Switch
3. J285 - Instrument Cluster Control Module
4. J519 - Vehicle Electrical System Control Module
5. J527 - Steering Column Electronic Systems Control Module
6. J533 - Data Bus On Board Diagnostic Interface
7. J844 - Automatic High Beam Control Module
8. A - CAN Bus Comfort
9. B - Wire Connection
10. C - LIN-Bus
11. D - CAN Bus Extended
12. E - Instrument Cluster CAN Bus/Chassis

In case of a malfunction (communication with the automatic high beam control module -J844- is not possible, the view for the CMOS camera is blocked or the automatic high beam control module is faulty), then the driver will be warned

1. A gong will sound one time when there is a malfunction (high beam assistant active or is being activated) The gong will sound again when the high beam assistant is activated again after switching the ignition on or off.
2. A message appears in the instrument cluster.

Different settings for the headlamps can be selected using the headlamp switch.

The following components are included in this function

1. Vehicle Electrical System Control Module -J519
2. Rain/Light Recognition Sensor -G397
3. Headlamp Switch -E1
4. Comfort System Central Control Module -J393
5. Tail Lamps
6. Headlamps

The vehicle electrical system control module -J519- reads the position of the headlamp switch -E1-.

The position of the headlamp switch can be read in the measured values from the vehicle electrical system control module -J519- (09 - electronic central electric)

The coding in the vehicle electrical system control module must be changed if the headlamp is changed or replaced.

The coding in the comfort system central control module -J393- must be changed if the tail lamps are replaced.

If a malfunction in the headlamp switch -E1- is recognized, then the vehicle electrical system control module will automatically switch on the driving lamps.

The buzzer in the instrument cluster control module -J285- will emit a warning tone whenever the driver door is opened and an exterior lamp is still on.

The vehicle electrical system control module may be coded only through the software version management.

The brakes lamps use terminal 30. If terminal 15 is switched off, the brake lamps will work when the brake pedal is pushed as long as the vehicle is not in bus rest.

1. Brake Lamp Switch -F
2. Pedal Bracket
3. Comfort System Central Control Module -J393
4. Brake Pressure Sensor 1 -G201
5. ABS Control Module -J104
6. Engine Control Module
7. Towing Recognition Control Module -J345

The following control modules have a wire leading to the brake lamp switch -F

1. Engine Control Module
2. Towing Recognition Control Module -J345
3. Comfort System Central Control Module -J393

The brake lamp switch is now switched by the pedal bracket. The connected control modules read the switch condition. The engine control module is the master of this function and sends the brake lamp on command to the CAN data bus.

Braking also takes place via brake pressure sensor 1 -G201-. When the brake pedal is pressed, brake pressure sensor 1 will transmit the brake pressure to the ABS control module -J104-. The engine control module imports the information via the data bus and then transmits this brake lamp on command to all the other control modules via the data bus.

The control modules switch on the brake lamps as soon as the wire or the CAN data bus transmits the brake lamp on command. This assures that the brake lamps will function even if there is an interruption in the wires.

1. The brake lamps are controlled by the comfort system central control module -J393-.
2. The brake lamps on a trailer are controlled by the towing recognition control module -J345-. The trailer control module provide the voltage to the trailer socket for the brake lamps.

The plunger on the brake lamp switch -F- automatically adjusts itself. The brake lamp switch must be locked into place. Refer to Anti-Lock Brake System .

The following blinking functions are possible only with the ignition on

1. Directing blinking
2. Comfort blinking

These are terminal 30 functions

1. Crash blinking
2. Warning blinking
3. Central locking blinking
4. Antitheft alarm system blinking

The Following Components Are Included In The Blinking Function

1. Warning Light Button -E229
2. Turn Signal Switch -E2
3. Vehicle Electrical System Control Module -J519
4. Steering Column Electronic Systems Control Module -J527
5. Anti-Theft Alarm System Sensor -G578
6. Driver Door Control Module -J386
7. Front Passenger Door Control Module -J387
8. Comfort System Central Control Module -J393
9. ABS Control Module -J104
10. Crash Sensors
11. Airbag Control Module -J234
12. Engine Control Module
13. Towing Recognition Control Module -J345

The bulbs are controlled by various control modules.

The bulbs can be checked with a diagnostic test in the vehicle electrical system control module -J519- and the comfort system central control module -J393-. The bulbs in the exterior mirrors can be checked via a diagnostic test in the door control modules.

The Coming Home function makes sure the vehicle is illuminated when you are exiting the vehicle in the dark.

Requirements

1. The vehicle has a rain/light recognition sensor.
2. The switch-on time in the MMI is set to 0 seconds
3. The function is coded in the vehicle electrical system control module
4. The headlamp switch is set to AUTO

Components

1. Rain/Light Recognition Sensor -G397
2. Vehicle Electrical System Control Module -J519
3. Driver Door Control Module -J386
4. Driver Door Contact Switch -F2
5. Headlamp Switch -E1
6. Comfort System Central Control Module -J393
7. Fog Lamps
8. Tail Lamps
9. License Plate Lamp

The function starts when the ignition is turned off and the driver door is opened. The key can remain in the ignition lock. In addition to this, the rain/light recognition sensor must report darkness to the vehicle electrical system control module -J519-.

Scheme 148

The opened door recognizes driver side door contact switch -F2-. The switch condition is imported via the driver door control module -J386- and the information is then sent via the data bus.

The vehicle electrical system control module turns on the fog lamps. The comfort system central control module -J393- turns on the tail lamps and the license plate lamps. Also, the parking lamp is switched on in Bi-Xenon headlamps.

The lamps will switch off after a preset time in the MMI elapses. The time calculation begins after the last door or rear lid is closed.

This function must be coded in the vehicle electrical system control module -J519-. This function is no longer available when the rest current - energy management engages. The rest current - energy management is active when the vehicle cannot be started.

The driver door contact switch -F2- is part of the driver door central locking unit -F220- and cannot be replaced separately.

The Leaving Home feature illuminates the vehicle when you are entering the vehicle in the dark.

Requirements

1. The vehicle has a rain/light recognition senso.
2. The function is switched on in the MMI.
3. The vehicle electrical system control module is coded.
4. The headlamp switch is set to AUTO.

Components

1. Rain/Light Recognition Sensor -G397
2. Vehicle Electrical System Control Module -J519
3. Headlamp Switch -E1
4. Comfort System Central Control Module -J393
5. Fog Lamps
6. Tail Lamps
7. License Plate Lamp
8. Key

The function starts when the all the requirements are fulfilled and the vehicle is unlocked. The vehicle can be unlocked by remote control or by actuation of one of the door handles on KESSY vehicles.

In addition to this, the rain/light recognition sensor must report darkness to the vehicle electrical system control module -J519-.

Scheme 149

The condition of the unlocked vehicle is sent to the data bus via the comfort system central control module -J393-. When the other additional requirements are met, the function is active. The vehicle electrical system control module turns on the fog lamps. The comfort system central control module turns on the tail lamps and the license plate lamps. The function stops when the ignition is turned on or a maximum of one minute after the headlamps are turned on.

This function must be coded in the vehicle electrical system control module -J519-. This function is no longer available when the rest current - energy management engages. The function will be locked after the vehicle is unlocked several times using the remote control and the ignition was not turned on in between.

The rest current - energy management is active when the vehicle cannot be started.

The backup lamps come on when reverse gear is engaged. How reverse gear is engaged depends on the transmission.

The following components are included in this function.

1. Transmission Range Gear Recognition Switch -F208- (manual transmission)
2. Vehicle Electrical System Control Module -J519
3. Comfort System Central Control Module -J393
4. Transmission Control Module -J217- (automatic transmission)
5. Multifunction Switch -F125
6. Tail Lamps

Reverse Gear Recognition, Manual Transmission

Engaging reverse gear activates the transmission range gear recognition switch -F208-. The vehicle electrical system control module -J519- recognizes that reverse gear is engaged by the resistance coding from the switch and then sends the information via the data bus.

Scheme 150

Reverse Gear Recognition, Automatic Transmission

By moving the selector lever, the multifunction switch -F125- tells the transmission to engage reverse gear. When reverse gear is engaged, a message is sent to the transmission control module -J217-. The control module transmits the information via the data bus. A message is also sent to the selector lever transmission range position display unit -Y26- and the R symbol lights up.

Scheme 151

Controlling the Tail Lamps

The vehicle electrical system control module -J519- processes the information for reverse gear and then transmits the information to switch on the backup lamps via the data bus. The comfort system central control module -J393- receives this information and switches on the tail lamps.

The information "reverse gear" on the data bus is processed by several other control modules and systems (parking aid, rearview camera, exterior mirror).

LICENSE PLATE LAMP

The license plate lamps are controlled by the comfort system central control module -J393-.

The license plate lamps cannot be switched on separately. The license plate lamps come on when the low beams are switched on.

CHANGING A BULB

The following table shows which bulbs are available depending on the type of headlamp.

The fog lamp and the tail lamp bulbs are easy to replace. Refer to [For engine(s) CAEB, CALA, CCBA] Exterior Lights, Switches .

The headlamp range control must be adapted to the different loads because of the different angles of the vehicle. This is especially important to prevent glare by oncoming traffic.

On Halogen headlamp systems the range control can be set manually. Bi-Xenon headlamps have automatic range control.

Advanced Front Lighting System (AFS) = cornering lamp

MANUAL HEADLAMP RANGE CONTROL DESCRIPTION

Halogen headlamps have manual headlamp range control. The headlamps can be adjusted to adapt to the vehicle load using the headlamp adjuster -E102-. The headlamp adjuster is connected to the motors. The driver can adjust the headlamp range control using the adjustment wheel so that oncoming traffic is not blinded.

AUTOMATIC DYNAMIC RANGE CONTROL DESCRIPTION

The automatic/dynamic range control adapts not only to the static vehicle load, but also to the dynamic chassis angles, such as when braking and accelerating.

The load is monitored by level sensors. The vehicle speed signal, the acceleration signal and the braking signal are processed by the automatic/dynamic range control. These parameters are evaluated by the headlamp range control module -J431- as the vehicle is moving. Motors then adjust the position of the headlamps. The adjustment of the headlamps must take place very quickly. The motors are actually stepper motors and the headlamp range control module communicates with the other control modules via the 500k baud drive CAN.

AUTOMATIC/DYNAMIC RANGE CONTROL WITH AFS DESCRIPTION

The automatic/dynamic range control with AFS has the same functionality as the automatic/dynamic range control. The automatic/dynamic range control with AFS includes the dynamic cornering lamp. The dynamic cornering lamp is also called the Adaptive Light.

The headlamp range control module -J431- the different driving parameters while the vehicle is moving, such as, the vehicle speed, the steering angle, the yaw rate, etc. The headlamps move when driving around curves based on the evaluation of the parameters. This provides optimal illumination of the street. Safety and comfort are increased because the range of view has been enlarged.

Integrated motors move the headlamps horizontally in a dynamic cornering lamp. The headlamp lenses and mounts do not move. The projection module does not move when the vehicle is stationary or being driven at less than 6 km/h.

The headlamp range control module communicates with the other control modules in the vehicle via the 500k baud drive data bus. The control module communicates with the power output stages in the headlamp via a 500k baud sub data bus. The advantage to this is that if there is a malfunction between the control module and the power output stage, only the function of the range control will stop, but not the entire drive data bus.

SHOW ROOM

"Show Room" makes it possible to see the effects of the dynamic cornering lamp. This way the headlamps can move horizontally depending on the position of the steering wheel when the vehicle is standing still. Show Room can be activated or deactivated using the diagnosis tester in the headlamp range control module -J431-. If the vehicle is moving at a very low speed, Show Room is automatically deactivated. The diagnosis tester must activated it again.

TRIP MODE

If the vehicle is driven in countries where the traffic drives on the other side of the road than where it is normally driven, both headlamps must be adjusted in such a way that the asymmetrical low beam does not blind the oncoming traffic. "Trip Mode" can be activated using the diagnosis tester in the headlamp range control module -J431-. After this feature is activated, the yellow range control warning lamp in the instrument cluster will come on for a short time after turning on the ignition.

The motors for the dynamic range control and the dynamic corning lamp can be checked using the diagnostic tester.

The motors and the sensors for the dynamic cornering lamp cannot be replaced separately. The entire headlamp must be replaced if there is a malfunction.

For adjusting the headlamps.

See also:
• Anti-Lock Brake System
• [For engine(s) CAEB, CALA, CCBA] Exterior Lights, Switches