General Electrical System - Service Techniques BMW M3 E90

Scheme 1081

Introduction

The term Personal Profile means: saving and retrieving individual settings in the vehicle.

For the first time in the E87, drivers can flexibly tailor a multitude of personalised functions to their own preferences without having to visit a BMW contractual partner. The simple configuration and automatic pre-setting of the vehicle relieves the burden on the driver and increases comfort and traffic safety. The Individuality element of the BMW brand is permanently boosted.

Personal Profile builds on the familiar Car & Key Memory (CKM). With the CKM, the customer can set some functions him/herself via control elements. Other functions have to be set by a BMW contractual partner via the diagnosis system.

With Personal Profile, the driver can configure almost all functions him/herself. A separate profile which is activated when the vehicle is unlocked can be saved for up to 3 remote controls (or ID transmitters for comfort access). In addition, further remote controls can be assigned one of these 3 profiles.

The system operates in a decentralised manner without an additional control unit. The settings are implemented directly by the executing control units.

Brief description of components

The control units involved can be split into the following areas

1. Control for central access to the profiles
2. Central display and control
3. Executing control units

Some control units are present in several areas: They are responsible for operation and for executing various functions.

Control for central access to the profiles

1. CAS: Car Access System For the Personal Profile, the various user profiles are saved in the CAS control unit. One or more remote controls can be assigned to a profile.

Central display and operation

Depending on the scope of the vehicle's equipment, one of the following control elements is available

1. KOMBI: Instrument cluster Vehicles in the lower equipment levels: Settings of the Personal Profile can be entered via a rocker switch on the turn signal/ main-beam switch. The settings are displayed in the LCD display in the instrument cluster.
2. RAD2: Radio 2, sales designation: BMW Professional radio A MOST bus is fitted for the BMW Professional radio and higher. The radio serves as the gateway (data interface) between the MOST bus and the K-CAN. The Personal Profile functions that can be set on the radio are transmitted to the instrument cluster via the K-CAN.
3. M-ASK: Multi-audio system controller The M-ASK is fitted with option 606 Business Navigation System. The settings of the Personal Profile are displayed on the Central Information Display (CID).
4. CCC: Car Communication Computer The Car Communication Computer is installed in connection with one of the following options: Option 609 Professional navigation system Option 620 Voice input system Option 601 TV function Several control units and the CD-ROM/MD/DVD players are integrated into a single housing. The CCC controls all information and communication systems.

Executing control units

1. CAS: Car Access System The CAS control unit is, amongst other things, the master for the central locking system, the electronic immobiliser and the electrical steering lock.
2. CID: Central Information Display The CID is connected to the M-ASK or the CCC. The display brightness and the control of the flap mechanism (only E87) can be set specifically for the driver.
3. DWA: Anti-theft alarm system Activation/deactivation of the anti-theft alarm can be confirmed acoustically or visually.
4. FRM: Footwell module The footwell module controls the signals to the exterior mirrors, central locking system and power windows as well as the lighting, for example. The FRM is also the interface to the instrument panel.
5. FZD: Roof function centre On the high equipment level, the condensation sensor of the IHKA and the rain-light sensor are connected to the roof function centre.
6. IHKA: Integrated automatic heating and air-conditioning system The special features of option 534 Automatic air conditioning system include the automatic recirculated air control and other programmes for air circulation. The response behaviour and the settings of the IHKA can be personalised.
7. SMFA: Seat module, driver The SMFA controls option 459 Electric seat adjustment with memory for driver's seat.
8. KOMBI: Instrument cluster The instrument cluster co-operates in message transmission for most personalised functions, e.g. with: Anti-theft alarm system Central locking system Seat/mirror memory Exterior lighting Display functions
9. RAD: Radio Option 667 BMW Audio radio is available without a drive. Option 662 BMW Business CD radio has a CD player. With this equipment, the vehicle does not have a MOST bus.
10. RAD2: BMW Professional radio Option 663 BMW Professional radio always has a CD player or an MD player. With BMW Professional radio or higher, a MOST bus is also present on the vehicle.
11. M-ASK: Multi-audio system controller The menus are displayed in colour on the Central Information Display (CID). In addition to the navigation, the M-ASK also includes audio functions and the interface between the MOST bus and K-CAN.
12. CCC: Car Communication Computer Several control units and the CD-ROM/MD/DVD players are integrated into a single housing. The menus are displayed in colour on the Central Information Display (CID). The CCC is used to control all information and communication systems.
13. SDARS: Satellite Digital Audio Radio Service A separate control unit is required for the Satellite Digital Audio Radio Service in the US versions.

System functions

Personal Profile can be split into 6 areas with sub-functions. Functions in a vehicle with full equipment

1. Central locking system/anti-theft alarm Confirmation Visual, deactivation/unlocking Visual, activation/locking Visual, locking without DWA Visual, unlocking without DWA Acoustic, DWA activation/deactivation (only for E90 US version) Selective unlocking Automatic locking of the central locking system 2 minutes after unlocking, if no door or hatch is opened After pulling away, from a certain speed
2. Seat/mirror memory Time of activation After unlocking the door After opening the door Position setting
3. Exterior lighting Delayed switch-off with dipped headlights Daytime driving light EURO One-touch flashing Automatic driving lights control
4. Heating, climate control, ventilation Saving programmes and settings for the air conditioning system Automatic mode Air stratification Driver/front passenger temperature Blower setting Automatic recirculated air control (AUC)
5. Displays, language Saving Unit of measure for tyre pressure Unit of measure for consumption Unit of measure for distance Time display Unit of measure for temperature Date display Display language Key assignment of one or two programmable keys on the multi-function steering wheel (MFL) Display brightness for CID Control of CID flap mechanism (only E87) Park Distance Control: PDC parking distance image
6. Audio Station memory Current volume for entertainment Speed-dependent volume control Sound settings Last audio source Equaliser settings

Operation

Depending on the vehicle equipment, different central control panels are available for Personal Profile

1. Vehicles with M-ASK or CCC are operated via the Controller and the CID.
2. Vehicles with BMW Professional radio (RAD2): The radio display has extended display options. For example, the language and format of the odometer and the time are set on the radio.
3. Equipment without CID or BMW Professional radio: A partial scope of the Personal Profile functions can be set on the instrument cluster.
4. Other functions can only be set via the BMW diagnosis system, depending on the equipment.
5. These functions can only be configured in the BMW diagnosis system: Anti-theft alarm system: interior movement detector active/not active Anti-theft alarm system: tilt alarm sensor active/not active

Memory conditions

Changes to the settings in the Personal Profile are effective immediately. For each function, the settings are saved directly in the relevant control unit.

The time at which the changes executed are saved depends on the data bus to which the control unit is connected

1. The control units in the K-CAN save the settings at the latest when the remote control is removed from the slot. For vehicles with the Comfort access option the settings are saved after the engine is switched off.
2. Control units on the MOST: After locking the vehicle and after the MOST bus falls asleep.

Note. The memory values are also retained after the battery is disconnected.

The control units retain the saved settings even after the battery is disconnected.

National versions

Note. National differences in the settings are possible.

Due to different legal stipulations, there may be national differences in possible settings.

1. Special features of US vehicles As an option, an acoustic confirmation of the alarm system can be set. The radio is available with a satellite tuner (SDARS).
2. Special features for EURO vehicles As an option, the EURO daytime driving light can be set.

Subject to change.

Scheme 1082

A digital compass in the interior mirror is offered as an optional extra (option 4NA) for the following BMW vehicles: 1 Series (only E82, E88), 3 Series, X3 and X5.

1. Up to 09/2006

A small LC display at top right in the interior mirror indicates the point of the compass in which the direction of travel is pointing: e.g. SW for South West.

1. from 09/2006

The display is effected with transmitted light technology. An LC display (window) is no longer needed. The display can be deactivated.

The compass offers an additional benefit especially in the USA. In large cities the streets are frequently arranged according to the points of the compass. The points of the compass are also marked on signposts.

The compass also makes orientation in European cities easier.

1. E88, E93 from 09/2008

The digital compass must be calibrated once with the soft top or retractable hardtop closed, and once with the soft top or retractable hardtop open.

The position of the soft top or retractable hardtop has an effect on the magnetic field in the vehicle. A deflected magnetic field will lead to calibration errors.

The following components deliver signals for the digital compass

1. Magnetic field sensor up to 09/2006 The magnetic field sensor is installed in the mirror base. The magnetic field sensor measures the current alignment of the magnetic field. The signal is sent to the control electronics for the compass in the interior mirror. from 09/2006 The magnetic field sensor is on the PCB in the interior mirror.
2. Control electronics for the compass The interior mirror is electrically connected to the roof control panel (FZD). The control electronics for the compass are integrated into the board for the interior mirror. The signals from the magnetic field sensor are received by the control electronics. The LCD display is activated directly by the control electronics.

The following components are controlled

1. Display in interior mirror up to 09/2006 The LC display (window) is situated at top right in the interior mirror. The points of the compass are presented digitally on the LCD display (LCD: Liquid Crystal Display). The display is divided into eight compass points. from 09/2006 The point of the compass is displayed in transparent light technology in the interior mirror as well. The display is also at the top right in the interior mirror. The display is divided into eight compass points.

The following system functions for the digital compass are described

1. Display
2. Brightness control of display
3. Adjustment of magnetic field zones and calibration
4. from 09/2006: Further adjustments
5. up to 09/2006: Fault display

Display

The 8 points of the compass are digitally displayed by abbreviations.

1. from 09/2006

The display is available in English and German (delivery status: English LHD)

N: North

NE: North East Nordosten)

E: East Osten)

SE: South East Sudosten)

S: South

SW: South West

W: West

NW: North West

The changeover between displays is carried out as follows

1. The current vehicle position is the centre of a 360° circle.
2. The eight points of the compass divide these 360° into sixteen 22.5° segments.
3. The display changes over if the direction of travel changes by more than 22.5°.

Brightness control of display

2 photodiodes in the electrochromic interior mirror record the surrounding brightness (1 photodiode for the surrounding brightness coming from the front, 1 photodiode for the surrounding brightness coming from the rear).

The photodiodes deliver the signals for the display brightness control.

The brightness of the display is adjusted by the interior mirror control electronics to suit the surrounding brightness.

1. E88, E93

A darkened interior mirror will become lighter while the soft top or the retractable hardtop is opening and closing.

The overhead control panel (FZD) transmits the signal (roof open or closed) to the control electronics for the interior mirror. The signal is transmitted on the wire that is also used for transmitting the signal for driving in reverse.

Adjustment of magnetic field zones and calibration

The worldwide magnetic field zones are permanently stored in the interior mirror. The magnetic field zones represent the deviations in relation to an ideal magnetic field for earth. The orientation "North" is precisely determined by the magnetic field zones.

The current magnetic field zone may be adjusted according to the geographic location. For example, Germany is located in magnetic field zone "8".

A vehicle has its own magnetic field. This makes it possible for the magnetic field sensor to measure an overlapping of the magnetic field with the earth's magnetic field. This overlapping is "worked out" by calibrating the compass.

A changed magnetic field is normally calibrated "automatically".

The vehicle's magnetic field may change under the following special circumstances

1. Powerful vibration during an accident
2. Very large external magnetic field - e.g. if a vehicle passes under a train when travelling through an underpass

However, a manual calibration may speed up the automatic calibration.

from 09/2006: Further adjustments

Different time-based adjustment menus can be obtained by means of the adjustment button

1. 0 to 3 seconds: Display ON/OFF
2. 3 to 6 seconds: Adjustment of magnetic field zones (0-15)
3. 6 to 9 seconds: Calibration (C)
4. 9 to 12 seconds: Left-hand drive or right-hand drive (L or R)
5. 12 to 15 seconds: English or German (E or O)

Release the adjustment button when the correct menu is obtained. Select values in the menu by pressing briefly. After approx. 5 seconds the value is stored and the menu is automatically exited.

up to 09/2006: Fault display

The LC matrix for the LCD display lights up completely if a system fault develops. A fault is displayed under the following conditions

1. If the vehicle is highly magnetised (2,200-2,500 milligauss), the measuring range of the magnetic field sensor will be exceeded.
2. If a fault develops in the circuitry of the magnetic field sensor.

Note. regarding the physical unit "gauss".

Gauss is the unit of measurement for magnetic flux density.

Preconditions for activation

At terminal 15 ON, the display is activated with a test run.

1. up to 09/2006

During this process, the LC matrix lights up completely (approx. 3 seconds). The digital compass is then switched on. There is no switch for turning off the LCD display at terminal 15 ON.

Scheme 1083

1. E81, E87, E90, E91, E92

Manually adjustable seats are fitted in the basic version.

1. E93

Option 459 is fitted as standard

Electric seats are available with the following special equipment packages

1. Option 459 "Electric seat adjustment for driver's seat and front passenger's seat with memory for driver's seat"
2. Option 481 "Sports seats for driver's seat and front passenger's seat"
3. Option 488 "Lumbar support for driver's seat and front passenger's seat"
4. Option 494 "Seat heating for driver's seat and front passenger's seat"

The sports seat option includes electric seat back width adjustment.

The system features the following switches and sensors

1. Seat adjustment switch block The buttons for seat adjustment are installed on the outside edge of the seat cushion. The number of buttons and their functions depend on the options fitted.
2. Switch for lumbar-support adjustment If lumbar support is fitted, the seat will have a rocker switch on the outside of the front.
3. Switch for seat back width adjustment If sports seats are fitted, the seat will have a rocker switch on the outside of the front.
4. Seat memory button Only the driver's seat features additional memory buttons for the seat memory.
5. Button for rear easy-entry facility E81, E92, E93 The rear easy-entry facility is controlled by the button on the seat backrest.
6. Backrest locking switch for driver and front passenger E93 The backrest locking switch monitors the locking of the respective backrest and forwards the information to the seat module concerned. If the backrest is not correctly locked, the seat module will issue a message on the K-CAN. The Check-Control message is shown in the instrument cluster and in the central information display. Seats with three-point seat belt integrated in the backrest are fitted on the cabriolet. If the backrest is not locked correctly, there is the danger that in the event of an accident occupants could move forward with the backrests and so have no restraint protection.
7. Seat heating switch The switches for the seat heating are located in the centre console switch cluster.
8. Hall sensors Hall sensors are provided for identifying of the position of seats with seat memory. The sensors are integrated in the seat drives.
9. Temperature sensor for seat heating A temperature sensor is installed in each of the seat cushions for the seat heating.

The seats are controlled by the following control units and bus systems

1. Seat module The driver's seat module (SMFA) control unit is fitted with the special equipment "Electric seat adjustment for driver's seat and front passenger's seat with memory for driver's seat".
2. Seat heating module If there is no seat module installed, the seat heating module takes over control of the seat heating. The seat heating module is not recognised as a control unit in its own right. In other words, the seat heating module is also capable of diagnosis.
3. JBE: Junction box electronics The junction box electronics is the central gateway in the vehicle. The junction box electronics controls the seat heating
4. K-CAN: Body controller area network K-CAN is a two-wire bus for communication between all control units connected to the K-CAN.

The following actuators are activated to perform the seat functions

1. Seat heating The seat cushion heating and backrest heating are installed such that they cover the entire area. Even the side sections and thigh supports are heated.
2. Seat adjustment drives The following drives are installed in the seat: Drive for fore-and-aft adjustment Drive for seat height adjustment Drive for seat cushion tilt adjustment Drive for backrest angle adjustment Drive for head restraint height adjustment (E93 only)
3. Lumbar support and seat back width adjustment Seat back width adjustment and lumbar support each comprise the following components: 2 air cushions (with lumbar support, the air cushions are called lumbar cushions) Electrically controlled valves. Seat back width adjustment and lumbar support have the same electric lumbar support pump.

The following displays provide seat status information

1. Seat heating LEDs 3 light emitting diodes (LEDs) in the centre console switch cluster indicate the switched status of the seat heating system.
2. Check-Control message for backrest lock E93 only The Check-Control message for a backrest that is not locked correctly is issued as follows: The seat belt indicator lamp in the instrument cluster comes on (visual seat belt warning) The Check-Control symbol is shown in the LCD display. The Check-Control message relating to the Check-Control symbol is shown in the Central Information Display (CID).

The system functions of the electrically operated seats include

1. Seat adjustment
2. Seat heating
3. Rear easy-entry facility

Seat adjustment

The seats fitted offer the following seat-adjustment options

1. Seat fore-and-aft adjustment (manual or with electric drive, 2 speeds with rear easy-entry facility)
2. Seat height adjustment (manual or electrically driven)
3. Seat depth adjustment (manual only, sports seat only)
4. Backrest angle adjustment (manual or electrically driven)
5. Seat back width adjustment (electropneumatic using air cushions, sports seat only)
6. Head restraint height adjustment (manual, electric drive only on E93)
7. Head restraint angle adjustment (manual only)
8. Adjustment of upper lumbar support (electropneumatic using lumbar cushion)
9. Adjustment of lower lumbar support (electropneumatic using lumbar cushion)

All these functions are actuated by the buttons on the outside of the seat cushion. Signals from the respective button trigger seat adjustment in the required directions.

Each drive is switched off when a certain threshold has been reached in order to reduce the load on the electric drives to a minimum.

With the special equipment "Electric seat adjustment for driver's seat and front passenger's seat with memory for driver's seat" the end stop is calculated for each drive. Hall sensors integrated in the drives register the adjustment distances which are processed in the seat module. If the drive should become blocked, the detected position value is interpreted as the end stop. All subsequent adjustments are interrupted just before this point.

Once the obstruction has been removed, adjustment can again extend beyond the newly detected end stop For this to happen, the seat adjustment button must be pressed again.

If the "Seat memory" option is not installed, there will be neither a seat module nor Hall sensors fitted. End stops are not stored with this equipment variant. The seat is adjusted until it reaches an end position. The junction box electronics (JBE) recognises the increased power draw of the respective drive at the end position. If the power draw exceeds a defined limit value, the JBE will switch this drive off.

A separate rocker switch is used to operate the lumbar support. An electric lumbar support pump supplies the lumbar cushions with compressed air. The individual air chambers are filled or emptied via several valves in order to vary the height and thickness of the lumbar support.

The seat back width adjustment is controlled by an additional rocker switch in the same way as lumbar support. An electric lumbar support pump supplies the air cushions with compressed air. The individual air chambers are filled or emptied via several valves

In this way the seat back width can be adjusted.

Seat heating

The seat heating system heats the seat cushion and backrest including the side sections.

The driver's seat and front passenger's seat each have a seat-heating switch in the centre console switch cluster (SZM).

The junction box electronics (JBE) actuates the seat heating. The seat heating is activated by a pulse-width modulated signal (PWM signal) from the seat heating module. The seat heating module records the temperature in the seats via a temperature sensor. The seat heating module regulates the heat output according to the selected heater level.

In the event of fault developing, the seat heating module will report the fault to the JBE. The seat heating module indicates this with a pulsed short-circuiting in the signal wire. If the JBE detects a fault message, the heated seat will be switched off. The JBE will store a fault memory entry.

Switching on again will reactivate the heated seat.

With the option "Electric seat adjustment for driver's seat and front passenger's seat with memory for driver's seat", the seat heating module for the driver's side is replaced by the seat module. The seat module is connected to the KCAN via the junction box electronics. The seat module automatically assumes control of the seat heating. If a seat module is fitted, the junction box electronics is not responsible for adjusting the driver's seat.

The seat heating is operational as from terminal 15 ON.

3 LEDs located above the seat heating switches indicate the heating stage currently active in the seat heating system.

Rear easy-entry facility

1. E81, E92, E93

The rear easy-entry facility is controlled by the buttons on the seat backrest.

To enable the rear-seat passengers to get in and out more comfortably, the front seat concerned can automatically be moved forwards and back again with the rear easy-entry facility button. The seat will return to its previous position.

Faster adjustment is achieved with the second speed of the drive for seat for-and-aft adjustment.

The rear easy-entry facility can only be activated under the following conditions

1. The vehicle must be stationary
2. The door must be opened

1. E93

The head restraint retracts when the locking lever for the backrest lock is mechanically released. This prevents the head restraint from making contact with the sun visor.

When the backrest lock is locked again, the head restraint moves back to its previous position.

Whether or not the head restraint retracts depends on the seat fore-and-aft adjustment.

If the seat is less than about 10 cm from the rearmost fore-and-aft adjustment stop, the head restraint will not retract. Reason: Sufficient space is available for folding the backrest forward.

Subject to change.

Scheme 1084

On the BMW 1-Series, 3-Series and on the BMW X5, the junction box assumes a central role in the vehicle. In the junction box, the distribution box and the junction box electronics form a single unit.

The junction box electronics is the central gateway in the vehicle.

The junction box consists of the distribution box and the junction box electronics.

1. JBE: Junction box electronics The junction box electronics unit combines numerous functions in a single control unit. The junction box electronics unit is connected via 4 plug connections. A 54-pin connector connects the instrument panel. Two further connectors are for the connection on the main wiring harness. These connectors are 54-pin and 47-pin. A 23-pin internal connection directly connects the junction box electronics to the power distributor.
2. Electrical distributors The fuses and various plug-in relays are located in the junction box distribution box. The boards in the distribution box are connected to various relays, depending on the equipment specification. There is an opening in the lower section of the junction box. The junction box electronics unit is connected with the distribution box through this opening.

Different versions of the power distributor are fitted, depending on the model series and Model Year measures. For example, the complete fuse assignment may change as part of Model Year measures.

1. 03/2007 Model Year measure (not E70, E71): primarily changes to pin assignment
2. 09/2007 Model Year measure (not E70, E71): primarily changes to fuse assignment

Depending on the vehicle equipment, various relays are mounted on the boards in the power distributor.

Numerous functions are provided in the junction box electronics (JBE). For example, the junction box electronics unit processes multiple signals, which it makes available to other bus subscribers on the electrical system. It also performs control tasks.

Depending on the model series and equipment, the following functions can be controlled or signals detected by the junction box electronics

1. Gateway The junction box electronics unit enables a number of bus systems to communicate with one another. The junction box electronics unit provides the gateway function for the following bus systems: Body CAN Powertrain CAN Diagnosis wire or D-CAN (diagnosis-on CAN) The chassis CAN (F-CAN) is connected to the junction box, but is merely looped through. After waking, the gateway is ready to send messages to the corresponding bus systems within 20 ms.
2. Power windows The footwell module (FRM) and the junction box electronics (JBE) control and monitor the power windows. The junction box electronics detects the following signals and makes them available to other bus subscribers: Power window switch, front passenger door Power window switch, rear door on the front-passenger side Power window switch, rear door on the driver's side Hall sensor, rear door on the driver's side Hall sensor, rear door on the front-passenger side The junction box electronics unit controls the following actuators: Power window drive, rear door on the front-passenger side Power window drive, rear door on the driver's side
3. Wiper/washer system The junction box electronics unit detects the following signals and makes them available to other bus subscribers: Reset contact, front Reset contact, rear The junction box electronics unit controls the following actuators: Wiper relay for wiper stage 1 and 2 Wiper relay for rear window Windscreen washer pump relay for headlamp wipe/wash unit
4. Central locking system The junction box electronics (JBE) is the executing control unit for the central locking system. The junction box electronics assume the task of actuating all central-locking system drives. The following control combinations are possible: Selective unlocking Deadlock release Locking Unlocking and deadlock release Deadlocking The boot lid lock is activated via its own output stage.
5. Climate control The junction box electronics (JBE) detect the following signals and makes them available to other bus subscribers: Sensor for automatic air recirculation mode Refrigerant pressure sensor Rear stratification control The junction box electronics unit controls the following actuators: Additional coolant pump Control valve for air-conditioning system or magnetic coupling Water valve (depends on engine equipment)
6. Seat heating A seat heating module or the more advanced driver's seat module can be fitted for the seat heating. A seat module is always fitted with seat memory. The junction box electronics unit (JBE) sends a request to check whether a seat module has been fitted. If the junction box electronics unit does not receive a confirmation, the JBE will take over control of the seat heating. The junction box electronics generate a pulse-width-modulated signal. This signal is used to control the seat heating module. If a seat module has been fitted, the seat heating is controlled directly by it.
7. Mirror heating and heated washer jets The junction box electronics (JBE) control the following actuators: Basic variant of mirror heating Heated washer jets If a mirror memory has been fitted, the LIN bus takes over control of the footwell module (FRM).
8. Bistable relay The bistable relay is used to shut down terminal 30g-f if there is a closed-circuit current fault. Similar to the micro power module (MPM), e.g. for E60 before 09/2005. The relay is built in for certain options only (e.g. CCC, M-ASK, TCU, ULF). If a bistable relay is fitted, an intelligent battery sensor will also be fitted.
9. Functions for instrument cluster The junction box electronics unit detects the following signals for the instrument cluster: Fuel level sensor 1 Fuel level sensor 2 Coolant level Parking brake warning switch Washer fluid level
10. Lock for second row of seats E70 The junction box electronics (JBE) monitor the locking of the second row of seats. A total of 5 microswitches are fitted in the second row of seats. The microswitches are used to verify that the second row of seats is correctly locked. The microswitches are wired in parallel directly with the junction box electronics. When the second row of seats is correctly locked, a signal is sent to the junction box electronics. If the signal is not received, the second row of seats is not correctly locked. The junction box electronics sends a message on the body CAN. The instrument cluster emits a Check-Control message.
11. DTC button The junction box electronics unit detects signals from the DTC button.
12. Parking brake warning switch The junction box electronics unit detects signals from the parking brake warning switch.
13. Roller sunblind for rear window The junction box electronics actuates the drive for the roller sunblind.
14. Servotronic valve On vehicles with Servotronic, the junction box electronics actuates the Servotronic valve (only on vehicles without option 217 "Active Steering").

Cable connector

As well as its electronic function, the junction box electronics unit (JBE) also has a connector function. Many of the wires from the 4 connectors that are connected to the junction box electronics are linked via the junction box electronics. The connections optimise the wiring harness. Here, the junction box electronics work as a node.

Junction box electronics relays

The junction box electronics unit (JBE) has internal and external relays. The excitation coils on all relays are permanently supplied with a positive cable. The positive power supply for the external relays is provided via the load circuit which is to be switched through. The positive power supply for the internal relay is provided via the fused junction box electronics supply wire. All relays are controlled via the negative lead. All internal relays and the relay for wiper stage 1 and wiper stage 2 are located downstream of the fuse on the current circuit. All other external relays on the junction box electronics are located upstream of the fuse on the current circuit.

The internal relays are

1. Relay for power window drive, rear
2. Relay for central-locking drive (except tailgate)

The external relays are

1. Relay for drive, rear window wiper
2. Relay for drives, wiper stage 1 and wiper stage 2
3. Relay for headlight washer system
4. Relay for heated rear window
5. Bistable relay (deactivation of closed-circuit current fault)

Scheme 1085

A network of hardware and software guarantees the power supply for vehicle systems. Two software functions are of fundamental importance for the power supply

1. Energy management
2. Power management

The energy management system ensures that sufficient starting power is always available.

The energy management system monitors the vehicle even when the engine is not running.

The energy management system comprises all vehicle components that generate, store and consume energy.

The data for the energy management system are divided among several control units.

The power management system is a subsystem of the energy management system. Power management is controlled by the engine control unit (DME or DDE: digital engine electronics or digital diesel electronics).

While the vehicle is being driven, the power management system regulates the output of the alternator and the battery charge.

The following components are involved in the power supply

1. Alternator The alternator generates the charge voltage for the battery and the power supply for the consumers. The alternator generates a variable voltage, depending on the engine speed (alternator voltage). The power management system regulates this variable voltage.
2. Battery The vehicle battery is fitted inside a plastic casing in the luggage compartment. The capacity of the battery installed depends on the engine used and the equipment installed in the vehicle.
3. Junction box The junction box is fitted behind the glove box underneath the instrument panel. The junction box consists of a power distributor and a control unit, the junction box electronics (JBE, see below). The power distributor holds fuses and relays. The following relays are of particular importance for the power supply: Terminal 15 relay Terminal 30g relay for consumer cutoff (see below under " «SYSTEM FUNCTIONS»(/bmw/m3/e90-2007-2013/remont/door-locks-anti-theft-systems/#general-electrical-system-service-techniques__system-functions) ") Terminal 30g-f relay for cutoff in case of fault (see below under " «SYSTEM FUNCTIONS»(/bmw/m3/e90-2007-2013/remont/door-locks-anti-theft-systems/#general-electrical-system-service-techniques__system-functions) ") Different versions of the power distributor are fitted, depending on the model series and Model Year measures. For example, the complete fuse assignment may change as part of Model Year measures. 03/2007 Model Year change: primarily changes to pin assignment 09/2007 Model Year change: primarily changes to fuse assignment Depending on the vehicle equipment, various relays are mounted on the boards in the power distributor.
4. Front and rear power distributors The BMW 1-Series and the BMW 3-Series have the following power distributors: Power distributor in the engine compartment: Electronics box Power distributor in the luggage compartment: Rear fuse block The fuse block is secured to the vehicle battery by a retaining clip. The fuse block can only be replaced as a complete unit. Fuses cannot be replaced individually. The fuse block holds the fuses for the following consumers: Valvetronic Common rail (fuel injection on diesel) Electric auxiliary heater Power distributor in junction box
5. Intelligent battery sensor Only on vehicles with High equipment level, e.g. CCC or M-ASK (CCC: Car Communication Computer, M-ASK: Multi-audio system controller) The intelligent battery sensor evaluates the current quality of the battery. The intelligent battery sensor is a part of the battery negative terminal. The intelligent battery sensor regularly (cyclically) measures the following values: Battery voltage Charge current Discharge current Battery temperature

The following control units are involved in the power supply

1. JBE: Junction box electronics The JBE is the control unit in the junction box. The JBE is the central data interface in the vehicle (gateway for the bus systems).
2. CAS: Car Access System The Car Access System is involved in the terminal control (terminal R, terminal 15, terminal 30g). The terminal control supplies important messages for the power supply. The CAS is connected to the following components and control units: The Car Access System is connected by a direct wire to the START/STOP button and to the slot for the ID transmitter. The START/STOP button and the slot are located next to the steering column. The starter motor and the DME/DDE are connected to the CAS. The CAS control unit is a bus subscriber on the K-CAN.
3. DME: Digital engine electronics or DDE: Digital diesel electronics The DME/DDE influences the power supply as follows: If the alternator voltage drops, the DME/DDE will increase the engine speed as needed. The software for this is called "power management". The DME/DDE is connected to the PT-CAN (Powertrain Controller Area Network) as part of the bus system. If an intelligent battery sensor is fitted, the DME/DDE will evaluate the current battery condition. In this way, the DME/DDE also influences terminal 30g-f (see below under " «SYSTEM FUNCTIONS»(/bmw/m3/e90-2007-2013/remont/door-locks-anti-theft-systems/#general-electrical-system-service-techniques__system-functions) ").
4. MRS: Multiple restraint system The MRS control unit interrupts the power supply as follows if an accident exceeding a certain severity occurs: The safety battery terminal is separated from the battery. The electric fuel pump is switched off. The following data buses and wires are important for the power supply
5. Bitserial data interface The bitserial data interface is the data connection between the engine control unit (DME/DDE) and the alternator.
6. 2 battery cables 2 battery cables connect the battery to the engine compartment: One of the battery cables runs via the jump-start connection point to the starter and alternator. The other cable is used for the voltage supply for the fuel injection system (on spark-ignition engines: Valvetronic, on diesel engines: Common rail system). Both battery cables are routed on the vehicle underbody on the BMW 1-Series and BMW 3-Series.

The following system functions of the power supply system are described

1. Power management with engine running: "Basic Power Management" functions with standard equipment and "Advanced Power Management" with High equipment level
2. Emergency operation in the event of bitserial data interface failure
3. Energy management even when engine is not running: Power supply for control units, consumer cutoff of auxiliary consumers and off-load current monitoring
4. Data transfer for power supply

Power management

The power management system is the most important component of the energy management system.

The power management system is a software package in the engine control unit (DME or DDE).

When the engine is running, the power management system regulates the alternator voltage.

Depending on the vehicle's equipment, there are 2 versions of the power management

1. Basic Power Management (BPM) on vehicles with standard equipment and only a few items of special equipment Basic Power Management controls the idle speed. Basic Power Management also specifies the charge voltage according to demand.
2. Advanced Power Management (APM) on vehicles with High equipment level, e.g. with the following items of special equipment: CCC: Car Communication Computer M-ASK: Multi-audio system controller BMW "Professional" radio in US version Telephone in US version. Advanced Power Management is only available with the intelligent battery sensor. Advanced Power Management gives precise consideration to the current battery condition: The intelligent battery sensor reads the corresponding data.

When the engine is running, the power management system regulates the following

1. Alternator voltage regulation When the engine is running, the alternator generates a variable voltage, the alternator voltage. This variable alternator voltage is regulated by the power management according to the following criteria: Nominal value for alternator voltage: The respective nominal value for alternator voltage depends on how many electrical consumers are switched on. Battery temperature: To prevent the battery from overheating, the optimum charge voltage is regulated. The alternator voltage is regulated by the engine control unit (DME or DDE). The alternator should always deliver as much current as the electrical consumers need. The engine control unit adapts the alternator voltage as follows, depending on the consumers in use: By increasing engine speed By increasing excitation current to alternator coils The data is exchanged via the bitserial data interface.
2. Battery charging regulation On vehicles without intelligent battery sensor, the battery temperature (for example) is calculated. On vehicles with intelligent battery sensor, the battery condition is recorded precisely by the intelligent battery sensor.
3. Load-dependent reduction of some consumers Only on vehicles with High equipment level and intelligent battery sensor On vehicles with intelligent battery sensor, consumers may be reduced or even switched off altogether, even if the engine is running. This consumer cutoff reduces current consumption in critical situations. This ensures that the battery is not discharged. The affected consumers are either switched off completely of their power output is reduced. On vehicles with diesel engine, the power consumption of the electric auxiliary heater is regulated.

Emergency operation in the event of bitserial data interface failure

If the bitserial data interface between the engine control unit and the alternator is interrupted, the alternator voltage will be regulated to a constant 14.3 V.

Energy management system

The energy management system is software package in several control units, e.g.

1. CAS: Car Access System
2. JBE: Junction Box Electronics
3. Engine control unit: DME or DDE).

The energy management system monitors and regulates the power supply, even when the engine is not running.

1. Power supply for control units To ensure that the vehicle retains its starting capability, there are two additional terminals for permanent current (terminal 30): Terminal 30g (active) Terminal 30g-f (cutoff in case of fault, only on vehicles with High equipment level). These new terminals allow consumers to be cut off and off-load current to be monitored when the vehicle is our of use.
2. Auxiliary consumer cutoff Terminal 30g (terminal 30 active): Terminal 30g means "active continuous positive": Components with power supply via terminal 30g are switched off according to time. The Car Access System (CAS) uses terminal 30g as follows to effect a time-controlled cutoff of control units and components with power supply: Approximately 30 minutes after terminal R is switched OFF, the power supply for these components is switched off. This prevents the battery from being subjected to excess load by the electrical consumers for too long when the vehicle is out of use.
3. Control unit cutoff in case of fault Cutoff in case of fault is only available on vehicles with High equipment level (e.g. on vehicles with CCC or MASK). Cutoff in case of fault helps to maintain the vehicle's ability to start. All control units and components on terminal 30g-f are cut off if any of the following faults develop: Control units frequently woken up after terminal R is switched OFF: Some control units do not "go to sleep", but rather remain active. Prolonged undervoltage on bus systems Data buses do not "go to sleep" after terminal R is switched OFF.

Data transfer for power supply

The CAS (Car Access System) forwards the data for the terminal control as follows

1. Terminal R ON or OFF
2. Terminal 15 ON or OFF
3. etc.

The CAS switches the corresponding relays for the following terminals

1. Terminal 15
2. Terminal 30g

The junction box electronics switch the corresponding relay for the following terminal

1. Terminal 30 g-f

The control units on these terminals are supplied with power and "woken up".

The corresponding vehicle systems are activated.

The consumers are primarily supplied via terminal 30g and terminal 30g-f (only on vehicles with High equipment level). However, certain consumers are also supplied directly from terminal 30.

For example, the anti-theft alarm must also be active when the ignition is switched off.

Scheme 1086

For the first time on a BMW, the E87 steering column switch cluster (SZL) will optically record the steering angle and the positions of the steering column stalks.

With a conventional steering column stalk the electrical contacts are mechanically switched and thus influence the pressure points felt by the driver.

The benefit of optical monitoring is that it allows these pressure points to be more precisely defined. In other words, optical monitoring greatly reduces the level of mechanical influence.

The steering column switch cluster (SZL) has the following tasks

1. Measuring the steering angle and steering-angle speed
2. Picking up signals from controls in the multi-function steering wheel via coil springs
3. Picking up signals from the steering column stalks
4. Sending data as CAN messages on the BUS or via direct wires
5. Looping signals through (e.g. driver's airbag and horn)

The steering column switch cluster (SZL) is connected to the vehicle wiring harness via 2 plug connectors.

The steering column switch cluster consists of the following components

1. Evaluation electronics The evaluation electronics analyse the signals from the components and send them as CAN messages on the FCAN. The evaluation electronics include the following components: Microprocessor Power supply F-CAN connection Interfaces for optical and electrical input signals
2. Steering-angle sensor The steering-angle sensor optically detects the steering angle turned at the steering wheel by means of an encoded disc. The data is read and analysed by the evaluation electronics. The data is transmitted directly to the DSC via the FCAN. (F-CAN = Chassis CAN; DSC = Dynamic Stability Control.) Signal path: SZL -> F-CAN -> DSC
3. Steering column stalk The lever positions of all steering column stalks are optically monitored. The actions of pressing the buttons, turning the thumbwheels and pressing the rocker switches are detected by switching mats. The switching mats forward the position of the buttons and thumbwheels as voltage signals. Depending on the vehicle's equipment, the steering column switch cluster (SZL) could have the following steering column stalks: Wiper/washer switch The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are emitted onto the F-CAN as a CAN message (It is only possible to check the switch positions with the BMW diagnosis system via DSC as the steering column switch cluster is not directly connected to the diagnosis system). Cruise-control system steering column stalk The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are emitted onto the F-CAN as a CAN message (It is only possible to check the switch positions with the BMW diagnosis system via DSC as the steering column switch cluster is not directly connected to the diagnosis system). Turn-signal/main-beam switch The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are resistance-encoded and transmitted from the steering column switch cluster by direct wires to the FRM (footwell module). The signals for the on-board computer functions are transmitted by a direct wire to the instrument cluster (KOMBI).
4. Coil spring cassette The coil spring cassette has the task of transferring electrical signals to or from the steering wheel. The signals are transferred as follows: Airbag unit (signals to steering wheel) Signal path: MRS control unit -> SZL (signal simply looped through) -> Coil spring -> Airbag unit Horn (signal from steering wheel) Signal path: Horn switch -> SZL (signal simply looped through) -> Junction box Multifunction buttons (signal from steering wheel) Signal path: Multifunction buttons -> SZL -> F-CAN -> Junction box electronics (signal simply looped through) -> F-CAN -> DSC control unit (serves as gateway) -> PT-CAN -> Junction box electronics (serves as gateway) -> K-CAN -> Audio system (check switch positions with BMW diagnostic system using DSC)

The control units involved in the functions of the steering column switch cluster are as follows

1. DSC: Dynamic Stability Control The steering column switch cluster (SZL) does not have its own fault memory. All fault data for the steering column switch cluster are stored in the DSC control unit. The DSC is connected to the steering column switch cluster via the F-CAN (chassis CAN).
2. JBE: Junction box electronics The junction box electronics unit is the data interface (= gateway) between the K-CAN and the PT-CAN. (K-CAN = Body CAN; PT-CAN = Powertrain CAN). Signals from the F-CAN (Chassis CAN) are simply looped through. This means: Signals from the F-CAN are not received or evaluated by the junction box electronics. The F-CAN cables are simply routed through the junction box housing. The junction box consists of the junction box electronics and the electrical distribution centre.
3. FRM: Footwell module The footwell module controls the vehicle lighting. The footwell module is connected to the steering column switch cluster (SZL) by direct wires.
4. CAS: Car Access System The Care Access System reactivates the control units on the PT-CAN via the wake-up wire (terminal 15 wake-up).
5. KOMBI: Instrument cluster Information on the on-board computer functions can be called up via the on-board computer button (BC button) and the rocker switch. (The BC button and the rocker switch are integrated into the turn-signal/main-beam switch). The contents are displayed in the LCD display in the instrument cluster. The signals for the on-board computer functions are transmitted by a direct wire from the SZL to the instrument cluster.

The steering column switch cluster (SZL) comprises the following functions

1. Monitoring of steering angle and steering-wheel turns
2. Monitoring of signals from coil spring cassette
3. Reading of signals from wiper/washer switch and cruise-control system steering column stalk and output of signals on the F-CAN
4. Reading of signals from turn-signal/main-beam switch and resistance-encoded output of signals to the FRM
5. Reading of signals from the BC switch for on-board computer function and from the rocker switch (on turnsignal/ main-beam switch) and resistance-encoded output of signals to the instrument cluster
6. Self-diagnosis (fault memory in DSC)

Monitoring of steering angle and steering-wheel turns

The steering column switch cluster (SZL) records the following information for the DSC functions

1. Steering angle
2. Steering-angle rate
3. Steering-wheel turn

The relative steering angle gives the angular position of the steering wheel. A steering angle of ±180° can be measured. The information always remains stored, even when there is no current applied to the steering column switch cluster.

Zero calibration must be performed with the BMW diagnosis system in the following cases

1. Replacement of SZL (steering column switch cluster)
2. Coil spring cassette replacement
3. Replacement of DSC control unit
4. Working on the steering

Information about steering-wheel rotations

The signal from the steering-angle sensor is repeated every 360°. These signal repetitions are used to count the number of turns of the steering wheel.

The steering column switch cluster has a permanent power source via terminal 30. This allows steering wheel movements to be detected even when the ignition is OFF.

Following a power interruption, the information about the number of turns of the steering wheel is lost.

When a journey is started, the steering column switch cluster will again measure the number of turns of the steering wheel.

If this process has not been completed when a speed of approximately 25 km/h has been reached, the DSC indicator and warning light will light up (repeat the process by restarting).

During measurement, the steering column switch cluster uses various pieces of information, including data from the wheel-speed sensors on the front wheels.

Not all signals are processed in the steering column switch cluster. Some signals are simply looped through the steering column switch cluster (e.g.: driver's airbag, on-board computer function, horn).

Information is transmitted via the F-CAN (Chassis CAN) or via direct wires to the systems or affected control units.

The steering column switch cluster (SZL) is activated

1. From the outside via the wake-up wire (terminal 15 wake-up) with bus activation (e.g. when the driver's door is opened)
2. From the inside by steering wheel movements (without bus activation, only for internal evaluation of the steering angle)
3. From the inside by movement of the turn-signal/main-beam switch (without bus activation, SZL is only active as interface to FRM, e.g. when park lights are switched on)

Scheme 1087

The footwell module (FRM) is an electrical node point in the footwell on the driver's side. The footwell module picks up the signals from the doors and controls the lighting. The footwell module also controls the adaptive headlights. The footwell module is also the interface to the dashboard.

The following components supply signals for the footwell module

1. Ride-height sensors
2. Reversing light switch
3. Brake light switch
4. Hazard warning lights switch
5. Light switch
6. Driver's door switch block
7. Door contacts in rear doors
8. Door contacts in front doors
9. Driver's door lock

Several control units are involved in the lighting: In a stricter sense, the following control unit are involved in the lighting system (in alphabetical order)

1. ACSM/MRS: Crash safety module/multiple-restraint system E81, E82, E87, E90, E91, E92: Multiple restraint system E70, E71, E93: (ACSM stands for "Advanced Crash Safety Module", also known as the crash safety module) The footwell module is connected to the crash safety module/MRS control unit via the K-CAN. In the event of an accident with corresponding severity, the footwell module automatically switches on the interior light hazard warning lights. E92 The crash safety module transmits a message about the status of the front-passenger seat-occupancy detector on the K-CAN. The belt feeder on the front-passenger side is only actuated if the front-passenger seat is occupied.
2. AHM: Trailer module The trailer module sends a signal indicating whether or not the vehicle is towing a trailer. The trailer module controls the trailer lighting. When a trailer is being towed, the trailer module automatically deactivates, for example the rear Park Distance Control (PDC) and the rear foglight on the vehicle. The automatic parking function is deactivated whenever a trainer is detected. (Automatic parking function: To improve the view of the kerb, the mirror glass is folded downwards when reverse gear is engaged. This brings the area close to the bottom of the vehicle, i.e. the kerbside, into view when parking.) The trailer module (AHM) is connected to the footwell module via the K-CAN.
3. DSC: Dynamic Stability Control When cruise control is in operation, the brake lights are actuated during automatic braking (legal requirement). To this end, a signal must be sent from the DSC to the accelerator pedal module via the PT-CAN.
4. FLA: Main-beam assistant In accordance with the traffic situation, the main-beam assistant sends a switch-on recommendation or a switch-off recommendation for the main-beam headlights to the light module or footwell module (FRM). On the basis of this recommendation and various other the input variables, the footwell module decides whether the main-beam headlights should be switched on or off.
5. FRM: Footwell module The footwell module is connected to the vehicle with three connectors. Two 51-pin connectors connect the main wiring harness. A further 26-pin connector is provided for the connection to the dashboard.
6. FZD: Roof control panel The roof control panel is responsible for the interior lighting components in the roof area. The basic variant of the roof control panel does not have its own control unit. The front interior lights and the rear interior lights are actuated by the footwell module (FRM). The High variant of the roof control panel has its own control unit: the FZD control unit. The footwell module is connected to the FZD control unit via the K-CAN.
7. JBE: Junction box electronics The luggage compartment lights and the glove compartment lighting are connected to the junction box electronics.
8. LDM: Longitudinal dynamics management In conjunction with the LDM, the option "Active Cruise Control" uses the "turn signal" signal from the footwell module to help when changing lanes. In other words, if a left turn signal is given before overtaking, the distance to the vehicle in front is reduced. The vehicle to be overtaken is "ignored" more easily. Conversely, when you move back into the right lane, vehicles being driven there will be monitored more quickly.
9. RLS/RLSS: Rain-light sensor/rain-light solar sensor E81, E82, E87, E90, E91, E92, E93: Rain-light sensor E70, E71: Rain-light solar sensor The rain-light sensor measures the ambient brightness outside the vehicle. Depending on the ambient lighting conditions, the footwell module will switch the driving lights on or off. To do this, the automatic driving lights control must be activated (light switch in switch position "A"). In twilight conditions, the rain-light sensor sends the message "Twilight". The footwell module switches the driving lights on. The automatic headlight-range adjustment for the dipped-beam headlights is actuated. In darkness, the rain-light sensor sends the message "Darkness". The adaptive headlights are then activated when the vehicle is cornering.
10. SZL: Steering Column Switch The switch signals from the turn-signal/main-beam switch are picked up and evaluated by the SZL. The evaluated switch signals are resistance-encoded and transmitted from the SZL by direct wires to the footwell module.

The following components are controlled

1. Exterior mirrors
2. Power window drive
3. Headlights
4. Rear lights
5. Front foglights
6. Additional brake light
7. Auxiliary turn signal light
8. Courtesy lighting, front
9. Courtesy lighting, rear
10. Licence-plate light
11. 2 stepper motor controllers for the adaptive headlight stepper motors
12. 2 belt feeder controllers (E92 only)

Belt feeder controllers (E92 only)

The footwell module (FRM) actuates the two belt feeder controllers for the driver's side and front-passenger side. The belt feeder controllers are connected to the footwell module via a LIN bus.

The belt feeder controllers actuate the drive of the belt feeder.

The position of the drive is reported back to the belt feeder controller by a Hall sensor in the drive.

The end position of the extended belt feeder is recorded by another Hall sensor. The end position is indicated to the belt feeder controller.

The belt feeder controller transmits both signals to the footwell module (FRM) via the LIN bus. The actuation circuit is located in the footwell module.

The belt feeder on the front-passenger side is only actuated if the front-passenger seat is occupied.

The following functions are executed by the footwell module

1. Gateway between LIN bus and K-CAN
2. Activation via various signals
3. Storing vehicle order
4. Other functions

Gateway between LIN bus and K-CAN

The footwell module (FRM) enables communication to take place between the LIN bus and the K-CAN.

The footwell module transfers the messages to the relevant recipient bus.

Components on the LIN bus

1. Special equipment exterior mirrors
2. Switch block in driver's door, High variant
3. 2 stepper motor controllers for the adaptive headlight stepper motors
4. 2 belt feeder controllers (E92 only)

Activation via various signals

The footwell module (FRM) can be woken up via the following signals

1. K-CAN active
2. Terminal 15 ON
3. Hazard warning switch ON
4. Change in state of door contacts
5. Anti-theft alarm system alarm

Storing vehicle order

The vehicle order is stored in the footwell module (FRM). For the order to be stored, terminal 15 must be ON and the vehicle must be travelling at a road speed of less than 5 km/h.

The vehicle order enables the vehicle to be identified. Besides the type code number, the vehicle order contains all important equipment features on the vehicle.

Other functions

The footwell module (FRM) influences various functions on the vehicle. The following components are controlled by the footwell module

1. Exterior mirrors
2. Exterior lighting
3. Interior lighting
4. Central locking system
5. Power windows

Door mirrors

There are 2 versions of the switch block in the driver's door

1. Switch block in the driver's door, basic variant The switch block sends its signals directly to the footwell module (FRM).
2. Switch block in driver's door, High variant The switch block is connected to the LIN bus. The requests to adjust the mirror are sent via the LIN bus. The footwell module (FRM) receives and processes the signals via the LIN bus. The footwell module scans for requests from the driver's door High switch block every 20 milliseconds. In sleep mode, the power supply is disconnected. The exterior mirrors cannot be actuated. The mirror heating is controlled by the footwell module. The corresponding signal is fed via the LIN bus to the electronic evaluation unit in the mirror. If a mirror memory is fitted, the footwell module will store the memory position of the mirrors.

Exterior lighting

The lighting functions are integrated into the footwell module (FRM).

These lighting functions are

1. Parking lights
2. Main-beam headlights
3. Headlight flasher
4. Turn signals
5. Hazard warning lights
6. Brake lights
7. Dipped-beam headlights
8. Reversing light
9. Front foglights
10. Rear foglight
11. Parking lights

Besides the lighting functions, other exterior lighting functions are also integrated in the footwell module

1. Light monitoring
2. Headlight beam throw adjustment
3. Emergency operating mode if the footwell module should fail
4. Lamp replacement (important lighting functions are substituted by other lights being actuated in the event of individual lights failing.)
5. Follow-me-home lights
6. Visual alarm after anti-theft alarm has been triggered (the visual alarm is given as per encoding with hazard warning lights, turn signals with dipped headlights or turn signals with main-beam headlights.)
7. Actuation of bi-xenon headlamps
8. Control of the stepper motor controller for the adaptive headlights
9. Turning light The turning lights are coupled to the adaptive headlights.

All lighting functions except the additional brake light are supplied with a pulse-modulated signal by the footwell module (FRM). This PWM signal allows constant brightness of exterior lighting.

Interior lighting

On vehicles without roof control panel (FZD), the footwell module actuates the interior lighting in the roof area directly.

All footwell module outputs for interior lighting are pulse-width modulated. This ensures that the brightness of the interior lighting always remains constant in spite of voltage fluctuations.

With standard equipment, the interior lighting comprises the following components

1. Front interior light
2. Luggage compartment lighting
3. Glove compartment lighting
4. Footwell lighting

The following components can also be installed as special equipment for the interior lights

1. Rear interior light
2. Courtesy lighting

Central locking system

The footwell module evaluates the status of the Hall sensors in the door contacts.

When the vehicle is locked or unlocked with the mechanical key element, the footwell module will recognise this request. The footwell module will send a message through the K-CAN to the CAS (Comfort Access System).

Power windows

The footwell module (FRM) and the junction box electronics (JBE) actuate the power window drives.

The relays for the front power window motors are located in the footwell module. The relays for the rear power window drives are located in the junction box electronics.

The footwell module (FRM) receives a large number of input signals that switch on the interior lighting. The input signals are directly read into the footwell module or are received via the K-CAN.

The following signals switch the interior lighting ON

1. Interior lighting button pressed
2. Door opened
3. Vehicle unlocked at driver's door lock cylinder
4. Vehicle unlocked with remote control
5. Terminal R OFF, if terminal 58g was ON no more than 2 minutes earlier
6. Crash signal
7. Lock button on remote control pressed when central locking system has been in central double-locking for at least 10 seconds

The interior lighting is switched off under the following conditions

1. Central locking system set to thiefproof mode, all doors and the tailgate closed
2. Interior lighting button pressed for longer than 3 seconds
3. Terminal 58 ON and terminal R OFF
4. Terminal R ON with doors closed
5. The vehicle is unlocked with the remote control and no door is opened with the space of 20 seconds
6. Terminal R OFF and a car door left open for longer than 1 minute
7. "Power Down" via diagnosis
8. 8 minutes after terminal R OFF

When terminal R is switched OFF, the footwell module (FRM) will switch the interior lighting off after 8 minutes. To do this, the footwell module sends the message for consumer shutdown via the K-CAN. The roof control panel (FZD) receives this message and switches off the interior lighting in the roof area. Interior lights that are switched on directly by the footwell module are also switched off.

The footwell module makes terminal 58 g available via K-CAN or via conventional wiring. Terminal 58 g is pulse-width modulated and has two brightness levels.

1. Brightness level for locating lights The brightness for the locating lights can be set individually with the rocker switch on the steering-column stalk.
2. Brightness level for function lighting The brightness level for function lighting is not dimmed and is switched on at full intensity.

As soon as the hazard-warning lights switch is pressed, the lighting in the hazard-warning lights switch is switched on at full intensity by the footwell module. If terminal 58 g is activated, the hazard-warning lights switch will no longer be illuminated with full intensity. Brightness depends on the setting for the locating lights.

In the vehicles of today, components and control units are networked by means of data buses. Data buses are capable of transmitting messages and signals.

The connected control units only read off those messages and signals that are of relevance to their operation.

Most buses are CAN buses (CAN: Controller Area Network).

A fibre-optic cable is used for navigation and entertainment: The MOST bus (MOST = "Media Oriented System Transport").

It has its own data wire for diagnosis: the diagnostics cable, also known as the "K-line"

Note. Abbreviations for control unit names

In the overviews of bus structures, all diagnosis and programming control units are indicated by abbreviations.

The abbreviations used for the control units are listed in alphabetical order and explained in the SI technology bulleting "abbreviations.

The following control units are numbered

1. Control units that cannot be programmed and cannot be encoded and which do not appear in the quick test. These control units do not have an abbreviation, just a number.
2. Control units with control unit designation from the time before electrical system 2000: Besides the abbreviation, these control units have a number for entering in the table. On the history of control unit designations: Since the start of series production of the E65 (electrical system 2000), the control unit designations have been harmonised. Earlier model series have varying control unit designations. For technical reasons associated with the system, these control units have not been renamed. This is because: These control unit designations appear in the quick test on the BMW diagnosis system.

Buses and control units in the E60, E61, E63, E64

In the E60, the K-CAN S and K-CAN P from the E65, E66 have been combined to form the K-CAN.

This means the E60 has the following buses: byteflight (until 09/2005), K-CAN, MOST, F-CAN, PT-CAN plus a local CAN (for the engine management system).

The central interface for exchanging data between buses is the safety and gateway module (SGM).

Note. Modifications in the bus structures on the E60, E61, E63, E64 from 03/2007

From March 2007, the bus structures are modified as follows

1. The D-CAN is now also integrated: D-CAN (diagnosis-on CAN) supersedes the previous diagnosis interface in all parts of the world.
2. The GWS is now also integrated: A new control unit has been integrated on the PT-CAN for selecting the drive position in the automatic transmission. GWS: Gear selector switch With the gear selector switch, the automatic transmission is no longer actuated mechanically, but rather electronically.
3. The TLC is now also integrated: A new control unit has been integrated on the PT-CAN for the driver assistance system. TLC: Track lane control Track lane control supports the driver by vibrating the steering wheel to warn him if the vehicle unexpectedly drifts off of the regular course, prompting him to countersteer.
4. The LDM and LRR are also integrated: With the introduction of active cruise control with stop & go function, 2 new control unit are integrated for cruise control: LDM: Longitudinal dynamics management LRR: Long range sensor The control unit for longitudinal dynamics management (LDM control unit) is connected to the PT-CAN. The long range sensor is connected to the LDM and the close-range sensors by the new sub-bus. The sub-bus is called the sensor CAN (S-CAN).

Note. Modifications in the bus structures on the E60, E61, E63, E64 from 09/2005

From September 2005, the bus structures are modified as follows

1. No byteflight data bus The SZL control unit is connected to the PT-CAN and no longer to the byteflight. As before, the SZL control unit is connected to the F-CAN. Following control units are dropped together with the byteflight: SBSL: B-pillar satellite, left SBSR: B-pillar satellite, right TMBF: Door module, front-passenger TMFA: Door module, driver
2. ACSM is added. The crash safety system is controlled by a new control unit: ACSM: crash safety module The ACSM control unit is on the K-CAN.
3. ("ACSM" = Advanced Crash Safety Module or Management)
4. ALBBF and ALBFA are added. 2 new control units for the active backrest width adjustment are added on the PT-CAN. ALBBF: Active seat back width, front passenger seat ALBFA: Active seat back width, driver's seat
5. CA is added. A control unit for comfort access is added on the K-CAN. CA: Comfort Access
6. KGM is added. As of September 2005, the data interface for the buses is the body-gateway module (KGM). The previous data interface for the buses, the safety and gateway module (SGM) has been dropped. The following functions are integrated in the KGM control unit: Data interface for buses Outside door handle electronics Vehicle centre satellite micro-power module
7. IBS: Intelligent battery sensor The IBS is connected via the bit-serial data interface (BSD) to the engine control unit. The IBS has been part of the power supply on the BMW 5-Series since start of series production.
8. FLA is added. A new control unit for the main-beam assistant is added on the K-CAN: FLA: Main-beam assistant
9. For US vehicles: IBOC is added. For US vehicles, a control unit is added to the MOST for analogue and digital radio reception. IBOC: Digital tuner US
10. For Korea vehicles: KNAV is added. A control unit for the navigation system is added for vehicle in Korea. KNAV: Korea navigation system The KNAV control unit is connected to the MOST.
11. A new control unit for the night vision assistant is added on the K-CAN: NVE: night vision electronics
12. MPM dropped. No micro-power module (MPM) on the K-CAN. The KGM control unit performs the functions of the MPM.
13. For US vehicles: RDC is added. For US vehicles, a new control unit added on the K-CAN for monitoring tyre pressure has been. RDC: Tyre pressure control

Note. Modifications in the bus structures on the E60, E61, E63, E64 from 03/2005

From March 2005, the bus structures are modified as follows

1. AHL discontinued: From March 2005, the AHL control unit (adaptive headlights) is integrated into the light module. The light module is connected to the K-CAN and the PT-CAN.
2. The VTG is now also integrated: For the E60 and E61, an all-wheel drive vehicle is available. The control unit for the xDrive on the E60 and E61 is known as the VTG: Transfer case.

Note. Original version: Buses and control units on E60, E61 E63, E64 up to 03/2005

To support the workshops, the predecessor version of the bus structures on the E60 are also described below

Buses and control units in the E65 and E66

The main buses in the E65 and E66 are called: K-CAN P, K-CAN S, MOST, byteflight , Local CAN, PT-CAN.

Note. Modifications to the bus structures for the E65 and E66 from 03/2005

From March 2005, the AHL control unit (adaptive headlights) is integrated into the light module. The light module is connected to the K-CAN S and the PT-CAN.

Note. Predecessor version: Buses and control units on E65, E66 from 03/2004

To support the workshops, a description of the predecessor version of the bus structures on the E65 and E66 is also provided

The key modification compared to the original version of the bus structures on the E65 and E66 is

SIM and ZGM have been combined to create the SGM. The SGM is the central data interface for all buses and control units.

(SIM: safety and information module)

(ZGM: central gateway module)

(SGM: safety and gateway module)

Note. Original version: Buses and control units on E65, E66 up to 03/2004

To support the workshops, the original version of the bus structures on the E65 and E66 is also available

In the original version, the E65, E66 had the two control units SIM and ZGM.

1. SIM: safety and information module The SIM was the data interface for the control units on the byteflight data bus.
2. ZGM: Central gateway module The ZGM is the central data interface for all buses and control units.

Buses and control units in the E70

The important buses in the E70 are called: K-CAN, MOST, PT-CAN, F-CAN, FlexRay.

FlexRay is a new communication system that offers extremely efficient, real time data transfer between the electrical and mechatronic components in the vehicle. FlexRay has a data transfer rate of 10 MB it/s.

FlexRay is used for data exchange between the VDM control unit and the shock absorber satellites.

CHAMP: On the US national version, instead of the multi-audio system controller (M-ASK), the Central Headset And Multimedia Platform (CHAMP) operates as the BMW "Professional" radio. In contrast to M-ASK, CHAMP does not have a navigation system.

Buses and control units in E81, E82, E87

The important buses in the E87 are called: K-CAN, MOST, PT-CAN and F-CAN.

The MOST, the innovation in the bus structure on the E65 and E66, is now also used in the E81, E82, E87.

The central interface for data transmission is the junction box electronics (JBE) in the junction box.

Buses and control units on the E90, E91, E92, E93

The most important buses on the E90, E91, E92, E93 are: K-CAN, MOST, PT-CAN, F-CAN.

The new feature is that the footwell module (FRM) is connected to the PT-CAN. This is because

1. The adaptive headlights are integrated into the footwell module. The adaptive headlights need the high-speed PT-CAN.
2. The longitudinal dynamics management sends the signal for the brake light on the PT-CAN.

Buses and control units on the R50, R52, R53

The most important buses on the R55, R56 are: K-CAN, MOST, PT-CAN and F-CAN.

The central interface for data transmission is the junction box electronics (JBE) in the junction box.

Buses and control units in the R55, R56

The most important buses on the R50, R52, R53 are: K-bus, PT-CAN.

The central interface for data transfer is the instrument cluster (KOMBI).

Scheme 1088

The Car Access System (CAS) controls access to the vehicle.

The CAS control unit is the master control unit, e.g. for the following systems

1. Electronic immobiliser
2. Central locking system
3. Comfort Access
4. Electronic steering lock
5. Power windows

The CAS is constructed differently in the various model series.

1. E60, E61, E63, E64 until 09/2005

The CAS and the ignition starter switch are 2 separate components.

1. E60, E61, E63, E64 from 09/2005

Ignition starter switch and conventional ignition key discontinued. The slot for the remote control and the START/STOP button are new features.

1. E70, E81, E87, E90, E91, E92, E93 from start of series production

Slot and START/STOP button

The CAS consists of the following components

1. CAS control unit The CAS control unit is the master control unit for a number of systems. The CAS control unit is connected directly to the K-CAN (Body CAN).
2. Ignition starter switch E60, E61, E63, E64 up to 09/2005 The ignition starter switch switches the individual terminals of the ignition lock. Four Hall sensors are installed in the ignition starter switch. The Hall sensors read out the terminal status. The signals are forwarded to the CAS control unit.
3. START/STOP button and slot The ignition switch has been replaced by the START/STOP button and the slot for the remote control.
4. Electronic steering lock The electronic steering lock replaces the conventional mechanical steering lock. The electronic steering lock is located directly on the steering column. The electronic steering lock consists of a drive with gearing and locking pin. Electromechanical unlocking and locking is controlled by the CAS.

Note. Electric steering lock discontinued

The electric steering lock is discontinued on the following vehicles

1. E90, E91, E92, E93 from 12/2006, only US version with automatic or manual transmission
2. E60, E61 from 03/2007 with automatic transmission
3. E63, E64 from 09/2007 with automatic transmission
4. E70 from start of series production

The CAS comprises the following functions

1. terminal control
2. Comfort start
3. Control of the electronic steering lock
4. Remote control for central locking system
5. Centralised control of the central locking system
6. Centralised control of the power windows
7. Centralised control for CA (Comfort Access)
8. Waking of the MOST via the K CAN for a telematics service
9. Centralised data source for the vehicle order and redundant data storage for vehicle data

Terminal control

The CAS controls the following terminals via the ignition lock or START/STOP button and slot as follows

1. Terminal R To maintain the starting capability of the vehicle, the CAS shuts down terminal R automatically. if the driver's door is opened and closed and no seat occupancy is detected, terminal R will be switched off after 16 minutes.
2. Terminal 15 The CAS controls terminal 15 (= active positive) for all electrical systems.
3. Terminal 15 wake-up wire When terminal 15 is switched on, the control unit on the PT-CAN are activated by the wake-up wire.
4. Terminal 50L and 50L_RS During the starting operation, terminal 50L is connected to the starter. Terminal 50R_LS is connected to the SMG control unit for clutch control.
5. Switched terminal 30g Some consumers (e.g. SZM, CVM) are now on terminal 30g rather than directly on terminal 30. Terminal 30g is switched by the CAS. Shutting down the consumers on terminal 30g reduces the off-load current.

Convenient-start system

1. E60, E61, E63, E64 up to 09/2005

The starter is only activated until the engine is running.

If the engine does not start, the starting procedure is aborted after approximately 30 seconds. When the engine is already running, the starter motor is prevented from starting up again (if the ignition key is turned again).

The CAS holds the rolling code for the electronic immobiliser (EWS). This rolling code is transferred between the CAS and the DME control unit or DDE control unit. The DME control unit or DDE control unit does not enable the ignition or fuel injection until a valid rolling code (authorised ignition key) is detected.

1. E70, E81, E87, E90, E91, E92, E93 and E60, E61, E63, E64 from 09/2005

The starting procedure begins when the START/STOP button is pressed. The starter is only activated until the engine is running. If the engine does not start, the starting procedure is aborted after approximately 60 seconds. Only the driver's commands are picked up by the START/STOP button. The starting procedure is controlled by the CAS control unit.

The CAS will only carry out an engine start if all start conditions have been met. If a condition ceases to be met during the starting procedure, the starting procedure will be aborted.

Control of the electronic steering lock

1. E81, E87, E90, E91, E92, E93 and E60, E61, E63, E64 from 09/2005

After authentication by the CAS, current is applied to the electronic steering lock. Only at this point can the lock be unlocked or locked.

The engine may only be started if the electronic steering lock has been unlocked and secured.

The electronic steering lock can only be locked when the vehicle is stationary and the engine has been stopped. If no unlocking procedure or locking procedure is carried out, the electronic steering lock is rendered free of current and deadlocked.

Note. Electric steering lock discontinued

The electric steering lock is discontinued on the following vehicles

1. E90, E91, E92, E93 from 12/2006, only US version with automatic or manual transmission
2. E60, E61 from 03/2007 with automatic transmission
3. E63, E64 from 09/2007 with automatic transmission
4. E70 from start of series production

Remote control for central locking system

The remote control is used to operate the central locking and various additional functions.

The radio signals from the remote control are received by the remote control receiver and transferred to the CAS control unit.

Radio transmission of the remote control commands is encoded using a rolling code. This encoding rules out any possibility of manipulation.

The CAS manages the rolling codes of up to 10 remote controls.

During the vehicle unlocking procedure, the rolling code stored in the remote control is sent to the CAS. The CAS assigns a personal ID code to every remote control.

The CAS can assign up to 4 personal ID codes. If there are more than 4 remote controls, personal ID codes are assigned more than once. Which personal ID code is assigned to which remote control can be chosen at will.

The personalisation number controls the defaults encoded in the key memory. The CAS transfers the personalisation number to the control units on the data buses. The settings for the key memory are stored in the relevant control units.

Centralised control of the central locking system

The CAS control unit is the master control unit for the central locking system.

Depending on the control request, the CAS decides whether the central locking should be unlocked, locked or deadlocked.

1. E60, E61, E63, E64 up to 09/2005

The central locking system for the front doors is controlled by the door modules (driver's side door module and passenger's side door module). TMFA stands for driver's door module. TMBF stands for front-passenger door module.

The central locking of the rear doors, the tailgate, the rear window (E61 only) and the fuel filler cap is actuated by the body basic module (KBM). The appropriate commands are delivered on the data buses.

1. E60, E61, E63, E64 from 09/2005

The central locking of the front doors is controlled by the body gateway module (KGM). The door modules and the byteflight are discontinued.

The central locking of the rear doors, the tailgate, the rear window (E61 only) and the fuel filler cap is actuated by the body basic module (KBM). The appropriate commands are delivered on the data buses.

1. E70, E81, E87, E90, E91, E92, E93

The central locking of the doors, the tailgate, the rear window (E91 only) and the fuel filler flap is actuated by the junction box electronics (JBE) and by the footwell module (FRM).

Centralised control of the power windows

The CAS is the master control unit for the power windows.

Because of the various national versions, the functions of the power windows are heavily dependent on the encoding.

1. E60, E61, E63, E64 up to 09/2005

The power windows in the front doors are actuated by the door modules (TMFA and TMBF).

The window lifters for the rear doors are actuated by the body basic module (KBM). The appropriate commands are delivered on the data buses.

1. E60, E61, E63, E64 from 09/2005

The power windows in the front doors are controlled by the body gateway module (KGM). The door modules and the byteflight are discontinued.

The window lifters for the rear doors are actuated by the body basic module (KBM). The appropriate commands are delivered on the data buses.

1. E70, E81, E87, E90, E91, E92, E93

The power windows in the doors are actuated by the junction box electronics (JBE) and by the footwell module (FRM).

Centralised control for CA (Comfort Access)

With Comfort Access, an ID transmitter is needed instead of the usual remote control.

The ID transmitter also performs standard remote control functions.

Comfort Access can be used to carry out the following functions

1. Passive Entry Opening the vehicle or luggage compartment without actively using the ID transmitter
2. Passive Go Engine start without actively using the ID transmitter
3. Passive Exit Closing the vehicle without actively using the ID transmitter

The CAS control unit is the master control unit for all functions carried out via Comfort Access. Vehicles with Comfort Access are fitted with a CA control unit.

Waking of the MOST via the K CAN for a telematics service

The telephone control unit wakes up cyclically in order to check for receipt of a new request from the telematics (e.g. an SMS text message to switch on the auxiliary heating).

The MOST network is a closed ring only. For it to work, all bus participants in the MOST network must be "awake".

As a control unit in the MOST network, the telephone control unit is not able to wake the MOST.

The CAS sends the trigger signal from the telephone control unit via the K-CAN to wake the multi-audio system controller (M-ASK). The M-ASK then wakes the MOST. Only now can the telephone control unit check whether a telematics service needs to be executed.

Centralised data source for the vehicle order and redundant data storage for vehicle data

The vehicle order is stored in the CAS. The vehicle order describes the vehicle model, the national version and the items of optional equipment.

The following data is stored in the CAS redundantly with the instrument cluster

1. Vehicle identification number
2. Odometer status
3. Data for Condition Based Service CBS)

The vehicle identification number and odometer are used to prevent manipulation. CBS data are important for regular servicing. CBS data must not be lost.

CBS data are updated in the ignition key or remote control within a driving cycle.

A driving cycle is defined by

1. First updating carried out if: Terminal 15 ON and speed above 50 km/h at least once and from 09/2005: once over 41 km/h and speed drops back to below 30 km/h from 09/2005: below 39 km/h
2. The data is updated again if: Distance driven exceeds 10 km and speed above 50 km/h at least once and from 09/2005: once over 41 km/h and speed drops back to below 30 km/h from 09/2005: below 39 km/h

In addition, a concealed service function can be used to update the CBS data on the ignition key or remote control

1. Insert remote control -> Press and hold down central locking button -> Switch terminal 15 on

In the vehicles of today, components and control units are networked by means of data buses. Data buses are capable of transmitting messages with signals.

The connected control units only read off those messages and signals that are of relevance to their operation.

Most buses are CAN buses (CAN: Controller Area Network). There are several CAN buses with different data transmission rates in each car.

For example, the PT-CAN has a fast data transmission rate, the K-CAN a slower data transmission rate.

A fibre-optic cable is used for navigation and entertainment: the MOST bus (MOST = "Media Oriented System Transport")

There is a separate data wire for diagnosis: the diagnosis wire, also known as the "K-wire".

The following options are available for locating faults in data buses and in control units

1. Test module for CAN bus diagnosis in the BMW diagnosis system: "Bus system analysis" The test module is called up in the DIS (Diagnosis and Information System) as follows: "Function selection" button -> Complete vehicle -> Body -> Bus functions -> Bus analysis -> System analysis
2. Checking the terminating resistances: Checking the terminating resistances can also be important for bus diagnosis.
3. Test module for diagnosis on the MOST buses: "MOST system analysis" The test module is called up in the DIS (Diagnosis and Information System) as follows: "Function selection" button -> Complete vehicle -> Body -> Bus functions -> MOST functions -> MOST system analysis.

These two test modules and the installation points of the terminating resistances are described in detail below.

Bus system analysis

The bus system analysis narrows down the cause of intermittently occurring faults in the area of the data buses and control units.

The test results of bus system analysis state the following possible causes of fault

1. Data bus XY defective
2. Gateway XY defective (= interface for data exchange)
3. Control unit XY defective

Note. Diagnosis of intermittent faults and permanent faults.

All cases where a data bus or control unit only fails temporarily (i.e. intermittently) are difficult for diagnosis. In such cases, the entries in the control units' fault memories do not point unambiguously to an intermittent failure of a particular data bus or control unit.

Intermittent failure of a particular data bus or control unit causes many different fault memory entries in several control units.

If a data bus fails completely and permanently , the affected control units are no longer available for diagnosis. The fault is thus easy to locate.

Note. Path details for the "bus system analysis" test module

The test module is called up in the DIS (Diagnosis and Information System) as follows

"Function selection" button -> Complete vehicle -> Body -> Bus functions -> Bus analysis -> System analysis

In order to determine the cause of a system fault in the bus system the following prerequisites have been established

1. If a communication fault occurs in the control units of the bus system, then this communication fault is not shown in the fault memory of the control unit concerned. This also means that no "x" appears before this control unit in the short test.
2. The quick-test list contains "real" installed control units and a "virtual" control unit with following names: "CAN/ byteflight system analysis" on the E65, E66 and on the E60, E61, E63, E64 up to 09/2005 "CAN system analysis" on the E70, E81, E87, E90, E91, E92, E93 and R56 and on the E60, E61, E63, E64 from 09/2005 In this case, "virtual" means that this is not a real control unit but a wild card for all control units on the CAN bus or byteflight.
3. The short test for this "virtual" control unit reads the communication fault from all control units.
4. An "x" in front of this "virtual" control unit indicates that the short test has analysed one of the following faults: Breaks in the wiring in a bus Intermittent fault in control unit or gateway

Functions of bus system analysis

Bus system analysis is a test module that automatically executes the following steps

Step 1: Identification of engine type

Identifying the engine type is a prerequisite for bus system analysis, since: different engines generate different fault code memory entries for the same cause of fault.

Step 2: Read fault memories of all control units

Step 3: Check fault memory entries for undervoltage

If the vehicle has suffered an undervoltage, the undervoltage is the most likely cause of the bus failure. Bus system analysis checks whether a fault memory entry indicating undervoltage is present in at least 2 control units. If no undervoltage can be detected, continue with step 4.

Step 4: Check how many fault memory entries were found

If at least 1 fault memory entry is present, continue with step 5.

Step 5: Evaluation of fault memory entries and creation of a list of most probable fault causes

Bus system analysis computes the 3 most probable fault causes.

The 3 most probable fault causes are given in a list.

The most probable fault cause is at the top of the list.

Scheme 1089

Note. The number of stars denotes priority.

The stars in front of a cause of fault indicate how probable the cause of fault is. 5 stars denote the most likely cause of fault.

1 star is allocated to a cause of fault that has very low probability.

Step 6: Selection of the test module

The BMW diagnosis system proposes a separate test plan for each of the 3 most probable fault causes.

Terminating resistors

The installation locations are listed below for the purposes of measuring the terminating resistor values.

1. R56 F CAN Vehicles with Dynamic Stability Control (DSC) 1 resistor is in the DSC control unit 1 resistor is in the DSC sensor (under the front-passenger seat) PT-CAN 1 resistor is in the SZL control unit in the version with steering angle sensor (SZL: steering column switch cluster) 1 resistor is in the EPS control unit (EPS: electro-mechanical power steering)
2. E60, E61, E63, E64 F CAN Vehicles with AS (Active Steering) 1 resistor is in the cumulative steering-angle sensor in the steering box. 1 resistor is in the DSC sensor (under the front passenger seat). Vehicles without AS (Active Steering) 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control 1 resistor is in the DSC sensor 2 (under the front-passenger seat; DSC sensor 1 is under the driver's seat). PT-CAN 1 resistor is in the DSC control unit (DSC: dynamic stability control) 1 resistor is in the SGM control unit (safety and gateway module) From 09/2005, this resistor is in the KGM control unit (body-gateway module)
3. E65, E66 PT-CAN 1 resistor is in the wiring harness at the front on the right spring strut dome. This resistor can be disconnected from the PT-CAN. 1 resistor is in the wiring harness under the back seat. This resistor cannot be disconnected.
4. E70 F CAN 1 resistor is in the SZL control unit (SZL: steering column switch cluster) 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control) FlexRay If the vehicle is equipped with option 2VA "Adaptive Drive", the 4 damper satellites are connected to the VDM control unit via the FlexRay data bus. This option (special equipment) comprises 2 systems: Vertical dynamics management (VDM) and active roll stabilization (ARS: sales designation "Dynamic Drive"). A damper satellite is fitted to each shock absorber. Vehicles with "Adaptive Drive" 1 resistor in each damper satellite of the vertical dynamic management system (VDM) PT-CAN 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control) 1 resistor is in the EMF control unit (EMF: electromagnetic parking brake)
5. E81, E87, E90, E91, E92, E93 F CAN Different terminating resistors are used depending on the motorisation: Vehicles with engine N4... (basic variant and High equipment) 1 resistor is in the SZL control unit (SZL: steering column switch cluster) Vehicles with engine M47, M57, N5... (basic variant and High equipment) 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control) 1 resistor is in the SZL control unit (SZL: steering column switch cluster) PT-CAN Different terminating resistors are used depending on the motorisation: Vehicles with engine N4... (basic variant and High equipment) 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control) 1 resistor is in the JBE control unit (JBE: junction box electronics) Vehicles with engine M47, M57, N5... (basic variant and High equipment) 1 resistor is in the DSC control unit (DSC: Dynamic Stability Control) 1 resistor is in the EKP control unit (EKP: controlled fuel pump)

MOST system analysis

The MOST bus has a ring structure. This means that a fault in one control unit can have an effect on the entire system. The cause of a system fault (= communication fault) in the MOST network is not readily apparent.

The "MOST system analysis" test module (BMW diagnosis system from DIS CD 36) was developed in order to analyse faults in the communication of MOST control units.

The MOST system analysis has been improved in DIS-CD 38.

Note. Path details for the "MOST system analysis" test module

The test module is called up in the DIS (Diagnosis and Information System) as follows

"Function selection" button -> Complete vehicle -> Body -> Bus functions -> MOST functions -> MOST system analysis

In order to determine the cause of a system fault in the MOST network, the following prerequisites have been established

1. If a communication fault occurs in MOST control units, then this communication fault is not shown in the fault memory of the control unit concerned. This also means that no "x" appears before this control unit in the short test.
2. In addition to the list of "really" fitted control units in the short test, a "virtual" control unit appears called "MOST system analysis". In this case, "virtual" means that this is not a real control unit, but a wild card for all MOST control units.
3. The short test for the "MOST system analysis" "virtual" control unit reads the communication faults of all the MOST control units.
4. An "x" in front of this "MOST system analysis" "virtual" control unit indicates that the short test has analysed one of the following faults: No communication with the following control units: R56 CCC: Car Communication Computer RAD2: radio 2 (Radio Boost) E60, E61, E63, E64 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform E65, E66 CD: Control display E70 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform E81, E87, E90, E91, E92, E93 CCC or M-ASK: car communication computer or multi-audio system controller RAD2: radio 2 (BMW radio "Professional") MOST ring break Fault in a MOST control unit

Functions of MOST system analysis

The "MOST system analysis" test module follows the following sequence

Step 1: Read fault code memories of MPM, KGM, PM or JBE

1. It first checks whether the communication with the following control units is in order: R56 JBE: Junction box electronics E60, E61, E63, E64 up to 09/2005 MPM: micro-power module E60, E61, E63, E64 from 09/2005 KGM: body gateway module E65, E66 PM: power module E70 JBE: Junction box electronics E81, E87, E90, E91, E92, E93 JBE: Junction box electronics
2. Then the fault memories are read. The following fault code memory entries are read: R56 JBE: Junction box electronics Have the auxiliary consumer units been switched off? E60, E61, E63, E64 up to 09/2005 MPM: micro-power module Have the auxiliary consumer units been switched off? E60, E61, E63, E64 from 09/2005 KGM: body gateway module Have the auxiliary consumer units been switched off? E65, E66 PM: power module Is there a break in the connection from the control units to the battery? Is the battery fully discharged? E70 JBE: Junction box electronics Have the auxiliary consumer units been switched off? E81, E87, E90, E91, E92, E93 JBE: Junction box electronics Have the auxiliary consumer units been switched off?

Step 2: Check communication with CD or CCC or CHAMP or M-ASK or RAD2

A check is performed as to whether the communication with the following control units is OK

1. R56 CCC or RAD2: Car Communication Computer or radio 2 (Radio Boost)
2. E65, E66 CD: Control display
3. E60, E61, E63, E64 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform
4. E70 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform
5. E81, E87, E90, E91, E92, E93 RAD2: radio 2 (BMW radio "Professional")

If there is a problem with the communication, the appropriate fault is displayed.

The test module is ended.

If communications with the headset are OK, continue with step 3.

(Headset: In the field of automobiles, the headset is the user interface for systems that are not essential for driving, for example navigation, mobile telephone or radio. Headset is a collective term for various control units, for example CCC, CHAMP, M-ASK, e.g in MOST system analysis).

Step 3: Check MOST ring

Is the MOST ring closed?

If the MOST ring has been interrupted a fault message is displayed. The test module is ended and reference given to the ring interruption diagnosis.

If the MOST ring is closed, continue with step 4.

Step 4: Check MOST configuration

This step checks whether the fault "MOST-Ring: desired/actual configuration do not coincide" is stored. Depending on the model series concerned, the fault is stored in the following control units

1. R56 CCC: Car Communication Computer RAD2: radio 2 (Radio Boost)
2. E60, E61, E63, E64 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform
3. E70 CCC or M-ASK or CHAMP: Car Communication Computer or multi-audio system controller or Central Head unit And Multimedia Platform
4. E81, E87, E90, E91, E92, E93 CCC or M-ASK: car communication computer or multi-audio system controller RAD2: radio 2 (BMW radio "Professional")

The test compares the desired configuration of the MOST bus with the actual configuration.

If the actual configuration differs from the desired configuration then the desired configuration for the control units is stored again in the MOST network.

If the desired configuration is stored, continue with the 5th step.

Step 5: Analyse fault memory of the MOST control units

The fault memory entries in all MOST control units are evaluated with regard to communication faults. The evaluation of the fault memory entries present will give the most probable cause of the fault.

At most the 2 most probable causes of the fault (control units) will be given as a result, e.g.

1. CDC CD changer (****)
2. TEL Telephone (**) Evaluation of quality of results: (*****) stands for high quality (most probable fault) (*) stands for poor quality The number of stars varies between one star and five stars. The necessary procedure is described.

Scheme 1090

Prior to the introduction of the roof control panel, the wiring in the roof was extremely complex.

Individual lines were required for the following functions

1. Interior lighting (front and rear)
2. Sliding/tilting sunroof
3. Anti-theft alarm system
4. Lighting for make-up mirrors
5. Electrochromic interior mirror with connection for electrochromic exterior mirrors
6. Rain-light sensor or rain-light solar sensor
7. Condensation sensor

Both basic and High variants of the roof control panel are available.

The High variant of the roof control panel is fitted in conjunction with specific optional equipment:e.g. sliding/tilting sunroof or with option 563 "Lighting kit".

The roof control panel optimises the wiring in the roof as follows

1. The roof control panel is the interface for the wiring in the roof.
2. The roof control panel also features other components, depending on the equipment fitted and the national version: Sliding/tilting sunroof switch Emergency call button Microphone Indicator lamp for front-passenger airbag deactivation Ultrasonic interior motion sensor (E70 only)

This summary of wires and components in the roof control panel optimises the previous construction.

1. Basic variant on basic version The basic variant of the roof control panel does not have its own control unit. It comprises the following components: Interior light, front Rear interior light (not E93) These two lights are activated via the footwell module.
2. High variant The High variant of the roof control panel has its own control unit. The FZD control unit (FZD: roof control panel). The High version of the roof control panel contains the following components, depending on the equipment fitted and the national version: Interior light, front Reading light, front (for driver's side and passenger side) Rear interior light Reading light, rear (left and right) Switch for sliding/tilting sunroof Microphone for telephone and emergency call Emergency call button Indicator lamp for front-passenger airbag deactivation Ultrasonic interior motion sensor (E70 only) E81, E87, E90, E91, E92 E93 E70

The roof control panel is available in several colours to match the headliner. Due to the number of equipment specifications, there are a total of 62 variants of the roof control panel (E70: 68; E93: 4).

The following components send input signals to the FZD control unit in the High variant of the roof control panel

1. 3 interior-light switches The interior light and the reading lights are switched on and off via 3 switches.
2. Light switch Switching Terminal R on and setting the light switch to switch position "A" or "2" also switches on the top-light.
3. Sliding/tilting sunroof switch The sliding/tilting sunroof switch is used to open and close the sliding/tilting sunroof and to tilt it upwards.
4. Hall sensors in the sunroof drive The Hall sensors in the sliding/tilting sunroof drive indicate the position of the sliding/tilting sunroof to the FZD control unit (in the roof control panel). E70, E91 The E70, E91 have 2 drives, each with 2 Hall sensors: 2 Hall sensors report the position of the glass sliding/tilting sunroof and the glass tilting roof (Panorama glass roof) 2 Hall sensors report the position of the sliding visor and the wind deflector. E91 with Panorama glass sunroof The E91 with Panorama glass sunroof has its own control unit for the Panorama glass sunroof (SHD: sliding/tilting sunroof). The Hall sensors report to the SHD control unit.
5. Wiper/washer system The position of the windscreen wiper switch is reported to the rain-light sensor or rain-light solar sensor via the FZD control unit. The rain-light sensor or rain-light solar sensor is activated by the "automatic wipe" button.
6. Condensation sensor Only vehicles with IHKA: integrated automatic heating and air-conditioning system The condensation sensor measures the moisture on the windscreen in the vehicle interior. The condensation sensor is able to detect condensation on the windscreen before it becomes visible. The condensation sensor is only active in the automatic program. The condensation sensor draws its power supply from the roof control panel. The roof control panel evaluates the condensation sensor data. The roof control panel sends appropriate data to the IHKA control unit (via the K-CAN). On receiving this data, the IHKA control unit starts the windscreen demisting program.
7. Electrochromic rear-view mirror If a strong light beam hits the electrochromic interior mirror, the electrochromic interior mirror sends an analogue signal to the FZD control unit. The FZD control unit controls the dimming of the electrochromic interior mirror. The electrochromic mirror glass darkens. In addition, the FZD control unit also converts the analogue signal into a CAN message. The CAN message is sent on the K-CAN, triggering the darkening of the electrochromic exterior mirror (optional equipment). The occupants of the vehicle are not dazzled by reflected light beams.
8. Ultrasonic interior motion sensor The ultrasonic interior motion sensor is a sensor for the anti-theft alarm system (DWA). The ultrasonic interior motion sensor is able to detect movements in the vehicle interior via ultrasonic signals. If the anti-theft alarm system is activated and movement is detected in the vehicle interior, an alarm is triggered. E70 The ultrasonic interior motion sensor is integrated in the FZD control unit. E81, E87, E90, E92 and E91 without Panorama glass roof The ultrasonic interior motion sensor is integrated in the rear interior light. E91 with Panorama glass sunroof The ultrasonic interior motion sensor is installed at the FZD control unit.
9. Selector lever or shift lever in the centre console If reverse gear is engaged, the electrochromic mirrors will not be dimmed.
10. Power supply from the distributor in the junction box The roof control panel draws its power supply from the distributor in the junction box. E81, E87, E90, E91 E92 3 positive cables connect the distributor in the junction box to the roof control panel: Terminal 15 Terminal 30 Terminal 30g, not E91 with option 402 "Panorama glass roof" E93 2 positive cables connect the distributor in the junction box to the roof control panel: Terminal 15 Terminal 30 E70 3 positive wires lead from the power distributor in the junction box and from the rear power distributor to the roof control panel: Terminal 15 from rear power distributor Terminal 30g with option 402 "Panorama glass roof" from rear power distributor, without option 402 "Panorama glass roof" from power distributor in the junction box, Terminal 30 from power distributor in the junction box The junction box houses a distributor and a control unit. The control unit is called the junction box electronics. The junction box electronics (JBE control unit) is the data interface for the following data buses: K-CAN (body CAN) PT-CAN (powertrain CAN) Diagnosis wire The signals from the F-CAN (Chassis CAN) are simply looped through the junction box. This means that the signals from the F-CAN are not received and processed by the JBE control unit. The F-CAN cables are simply routed through the junction box housing.

The following control units are associated with the FZD control unit (depending on the equipment)

1. CAS: Car Access System The CAS (Car Access System) control unit supplies the terminal status Terminal R ON. The CAS control unit is connected to the FZD control unit via the K-CAN. The CAS control unit supplies the "convenience closing" or "convenience opening" message for the sliding/tilting sunroof. E93 The CAS control unit is connected to the DWA control unit via the K-CAN (DWA control unit: siren with tilt alarm sensor and integrated DWA software)
2. CA: Comfort Access The CA (Comfort Access) control unit supplies the "convenience closing" or "convenience opening" message for the sliding/tilting sunroof. The request is sent when the outside door handle is pressed for longer than 2 seconds. Comfort Access is connected to the FZD control unit via the K-CAN.
3. DWA: Anti-theft alarm system For the DWA control unit, the FZD control unit is the interface to the K-CAN. The DWA control unit receives messages about the doors and engine hood as well as the boot lid (e.g. closed, open) via the K-CAN. The DWA control unit evaluates the signals from the ultrasonic interior motion sensor. The messages from the DWA are looped through the roof control panel. This means that the cables for the anti-theft alarm system are routed through the roof control panel housing. Messages from the DWA control unit are fed via a direct wire to the DWA LED. The DWA control unit is connected to the siren with tilt alarm sensor via the K-bus. E93 DWA control unit: siren with tilt alarm sensor and integrated DWA software The software for the DWA is integrated in the siren with tilt alarm sensor. E70 DWA control unit: FZD control unit with integrated DWA software The DWA LED is actuated directly by the FZD.
4. EGS: Electronic transmission control The EGS control unit supplies the "Reverse gear engaged" message for the electrochromic interior mirror (with automatic transmission). Signal path: EGS (electronic transmission control) -> PT-CAN -> Junction box electronics (JBE) in junction box -> KCAN -> FZD (roof control panel). If reverse gear is engaged, the electrochromic mirrors will not be dimmed.
5. FRM: Footwell module The footwell module (FRM) controls the interior and exterior lighting but not the reading light. The reading light is controlled by the roof control panel. The FRM control unit is connected to the roof control panel via the K-CAN.
6. IHKA: Integrated automatic heating and air-conditioning system The IHKA control unit receives the signals from the condensation sensor via the FZD control unit. The IHKA control unit is connected to the FZD control unit via the K-CAN.
7. KOMBI: Instrument cluster The instrument cluster control unit in the instrument cluster sends messages to the FZD control unit, e.g. regarding the dimming of the instrument lighting. The FZD control unit dims e.g. the LED in the sliding/tilting sunroof switch. The instrument cluster control unit also receives messages from the FZD control unit:e.g. the FZD control unit will send a message to the instrument cluster control unit when the anti-trap circuit on the sliding/tilting sunroof is triggered. The instrument cluster control unit then converts this message to a Check-Control message in the vehicle's system. The instrument cluster control unit is connected to the FZD control unit via the K-CAN.
8. RLS/RLSS: rain-light sensor/rain-light solar sensor The rain-light sensor or rain-light solar sensor is like the condensation sensor in the base of the electrochromic interior mirror. The RLS or RLSS detects water on the windscreen and the ambient brightness. The solar sensor in the RLSS also records the presence of light or heat sources (e.g. direct sunlight), which could affect the climate in the vehicle interior. The signals from the RLS or RLSS are used to control the wiper function and for automatic driving lights control. With the RLSS, the signals from the solar sensor are also used to control the functions of the air conditioning. The RLS or RLSS is a self-diagnosing control unit. The RLS or RLSS is connected by a LIN bus to the roof control panel (LIN: Local Interconnect Network, i.e. local data bus).
9. SZL: Steering Column Switch The SZL control unit sends signals to the FZD control unit, e.g. from the wiper switch. The SZL control unit is on the F-CAN (Chassis CAN). Data is transmitted to the K-CAN via a number of data buses and control units. Signal path: SZL -> F-CAN -> Junction box (merely looped through) -> F-CAN -> DSC (Dynamic Stability Control) -> PT-CAN -> JBE control unit in junction box -> K-CAN -> FZD -> Rain-light sensor or rain-light solar sensor.

In the High variant of the roof control panel, the following components are controlled by the FZD control unit

1. Interior lighting, front The interior lighting includes the interior lights and the reading lights, left and right. Front interior light The light source for the front interior light is a 6 W xenon lamp. Reading light for driver's side and passenger side There is one reading lamp each on the right and on the left. The light source for the reading lamp is a 6 W xenon lamp. LEDs for top-light The top-light comprises 2 orange LEDs.
2. Lighting for the make-up mirrors The lighting for the make-up mirror comes on automatically whenever the sliding visor for the make-up mirror is opened (regardless of whether or not the interior lighting is switched on). There is a make-up mirror on the driver's side and on the passenger side.
3. Rear interior light The rear interior light is activated by the FZD control unit as follows: On the basic variant of the rear interior light, the rear interior lighting is switched on together with the lighting in the front of the vehicle. The rear interior light in the basic variant does not have its own switch. The rear interior light is switched on by the FZD control unit. On the High variant, the signals from the rear interior lighting buttons are sent to the FZD control unit. The FZD control unit activates the required lights. The top-light is activated by the FZD control unit whenever the exterior lights are switched on. E81, E87, E90, E91, E92 The following variant-specific versions of the rear-compartment interior light are available: Basic variant rear interior light The basic variant, the rear interior light simply provides interior light. Rear interior light on the basic variant with cover for the ultrasonic interior motion sensor On the basic variant with ultrasonic interior motion sensor, the ultrasonic interior motion sensor is fitted in the rear interior light. High variant rear interior light On the High variant, the rear interior light provides both interior lighting and reading lights on the left and right. High variant rear interior light with cover for ultrasonic interior motion sensor On the High variant with ultrasonic interior motion sensor, the rear-compartment interior light features the ultrasonic interior motion sensor in addition to the interior lighting and reading lights. E70 and E91 with Panorama glass roof The ultrasonic interior motion sensor is located in the FZD (E70) or on the FZD (E91 with Panorama glass roof). E70 and E91 with Panorama glass roof The E70, E91 has 2 rear interior lights: on the C-pillar left and right.
4. Sliding/tilting sunroof drive E87, E90, E92 The FZD control unit actuates the sliding/tilting sunroof drive (dependent on the sliding/tilting sunroof switch or central locking system). E70 The FZD control unit controls 2 drives. One drive operates the two glass roofs (Panorama glass roof), the other the sliding visor and the wind deflector. E91 On the E91 with Panorama glass roof there is a separate SHD control unit for the 2 drives.
5. Rain-light sensor/rain-light solar sensor The FZD control unit sends important messages for the operation of the wipers to the rain-light sensor or rain-light solar sensor (via the LIN bus, see below in the " «SYSTEM FUNCTIONS»(/bmw/m3/e90-2007-2013/remont/door-locks-anti-theft-systems/#general-electrical-system-service-techniques__system-functions) " section)
6. Condensation sensor The condensation sensor draws its power supply from the roof control panel.
7. Electrochromic interior mirror and electrochromic exterior mirrors The roof control panel controls the dimming of the electrochromic mirrors as follows: the roof function centre control unit converts the analogue signal from the electrochromic interior rear-view mirror into a CAN message for the electrochromic door mirrors.
8. Ultrasonic interior motion sensor E70, E81, E87, E90, E91, E92 The ultrasonic interior motion sensor draws its power supply from the roof control panel. The ultrasonic interior motion sensor is in the DWA control unit. E70 The DWA control unit and ultrasonic interior motion sensor are integrated in the roof control panel.
9. 4 microwave sensors E93 The 4 microwave sensors use microwaves to record movement inside the vehicle interior. A movement is detected if the reflection (echo) of the microwaves changes. The range or sensitivity of the microwave sensors is preset (depending on the vehicle model and the equipment fitted). The microwave sensors are connected to the alarm system control unit by a single-wire bus (K-bus). The DWA control unit is connected to the K-CAN.
10. FBD receiver: Remote control receiver E81, E87, E93 The FBD receiver for the central locking system is installed in the interior mirror (FBD receiver is the receiver for remote control). In the standard equipment version, the FBD receiver draws its power supply from the power distributor in the junction box. If an FZD control unit is fitted (depending on the equipment variant), power is supplied from the power distributor in the junction box to the FBD receiver by the FZD control unit (wire is merely looped through). E90, E91, E92 The FBD receiver is located in the aerial amplifier in the headlining above the rear window. Power is supplied from the power distributor in the junction box. E70 The FBD receiver is installed in the aerial amplifier with aerial diversity in the tailgate. Power is supplied from the rear power distributor.
11. DWA LED The DWA LED is located on the underside of the interior mirror. The DWA LED flashes when the anti-theft alarm system is activated. When an alarm is triggered, the DWA LED lights up. The DWA LED draws its power supply from the roof control panel. The signal from the ultrasonic interior motion sensor for the DWA LED is simply looped through the roof control panel (i.e. the cable for the sensor is routed through the roof control panel). E70 The FZD directly actuates the DWA LED. E93 The DWA LED draws its power from power distributor in the junction box. The DWA LED is actuated by the DWA control unit (DWA control unit: siren with tilt alarm sensor and integrated DWA software).
12. Garage-door remote controls The 3 buttons for the garage door opener (also known as "integrated universal remote control") are in the interior mirror. The garage door opener draws its power supply from the roof control panel.

In the basic variant , the following lights draw their power supply from the roof control panel

1. Interior light, front
2. Rear interior light
3. E70 Reading light

These lights are activated via the footwell module (FRM).

In the high variant , the FZD control unit controls the following functions

1. Reading lamp
2. Interior lighting and top-light: Data transmission only from the buttons to the footwell module and from the footwell module to the lights (see below)
3. Sliding/tilting sunroof (except for Panorama glass sunroof E91)
4. Master for rain-light sensor or rain-light solar sensor
5. Self-diagnosis
6. The FZD control unit is the gateway (i.e. the data interface) for the following components and functions: Gateway between K-CAN and LIN bus Gateway for condensation sensor Gateway for Check Control Gateway for the electrochromic interior mirror and for the electrochromic exterior mirrors

The roof control panel can therefore be considered to have 3 functions

1. The roof control panel is an installation location for other components.
2. The FZD control unit controls some functions.
3. For a number of other functions, the FZD control unit acts as a gateway.

All of the above system functions are described in detail below.

1. The roof control panel is simply the installation location for the following components: Indicator lamp for passenger airbag deactivation The installation of an indicator lamp for passenger airbag deactivation depends on the equipment fitted and on the national version. The roof control panel is the installation location of the indicator lamp for passenger airbag deactivation. E81, E87, E90, E91, E92 The indicator lamp for passenger airbag deactivation is actuated by the MRS control unit (MRS = "multiple restraint system"). E70, E93 The ACSM safety system is employed on E70, E93 vehicles (ACSM = "Advanced Crash Safety Module", also known as "crash safety module"). The indicator lamp for passenger airbag deactivation is actuated by the crash safety module. Emergency call button Although the emergency call button is installed in the roof control panel, there is no electrical connection between it and the panel. The emergency call button is directly connected to the telephone control unit. Depending on the equipment fitted, the telephone control unit is the TCU or the ULF (TCU: Telematic Control Unit; ULF: universal charger and hands-free system). Microphone If a telephone has been installed, the two microphones for the telephone will also have been installed in the roof control panel. The two microphones are directly connected to the respective telephone control unit. E93 The microphone is located on the steering column. NOTE: From 09/2006, only 1 microphone is to be fitted. This change will be introduced gradually through the various model series. The installation location of the microphone in the FZD depends on the national version (LHD or RHD). That means: On LHD vehicles, the microphone is installed on the left. On RHD vehicles, the microphone is installed on the right.
2. The FZD control unit in the roof control panel controls the following functions: Controlling the reading lamp The FZD control unit evaluates the buttons for the reading lamp and activates the reading lamp. Control of interior lighting and top-light For the control of the interior lighting and the top-light, the FZD control unit simply transmits data to the footwell module. The interior lighting and top-light are controlled as follows: Interior light When the interior-light button on the roof control panel is pressed, the FZD control unit sends a corresponding message to the footwell module. The footwell module sends a "Switch ON" or "Switch OFF" request to the roof function centre control unit. The FZD control unit sends the "Switch ON" or "Switch OFF" request to the interior lights. The interior lighting is subject to the following regulations: Overrun of interior lighting: Depending on the encoding, the interior lights are switched on for a while after terminal R is switched off. The message is sent from the footwell module. Dimming: The interior lighting can be switched on dimmed or immediately at full illumination intensity. The message is sent from the footwell module when the interior-light button is pressed. The dimming settings are controlled by the FZD control unit. Controlling the power supply: The power supply for the interior lights is controlled by the FZD control unit with pulse-width modulation in order to compensate for voltage fluctuations in the vehicle's system. Consumer shutdown: The footwell module switches the entire interior lighting off when the "Consumer shutdown" message is sent on the K-CAN. This message is transmitted when the charge state of the battery is poor to maintain the battery's ability to start the vehicle for as long as possible, or for a defined time after terminal R is switched OFF. Top-light The top-light comes on automatically when Terminal R is switched on, along with the parking lights. Signal path: CAS (Car Access System) -> FRM (footwell module) -> FZD (roof control panel) -> LEDs for top-light. The FZD control unit simply transfers data from the FRM control unit to the top-light LED display Sliding/tilting sunroof control E70, E81, E87, E90, E92 The FZD control unit is responsible for controlling the sliding/tilting sunroof. The FZD control unit controls the sliding/tilting sunroof as follows: The FZD control unit evaluates the signals from the sliding/tilting sunroof switch. The FZD control unit actuates the sliding/tilting sunroof drive. E70 The FZD control unit controls 2 drives. The FZD control unit receives the signals from the two Hall sensors regarding the position of the sliding/tilting sunroof. E70 The FZD control unit also receives the signals from the two Hall sensors via the position of the sliding visor and the wind deflector. The FZD control unit executes the convenience closing request for the sliding/tilting sunroof (e.g. from the comfort access CA). The requests of the comfort access reach the FZD control unit via the K-CAN. E91 The E91 with Panorama glass sunroof (option 402) has a separate SHD control unit. On these vehicles, the FZD control unit evaluates the sliding/tilting sunroof switch. The FZD control unit sends the "Open", "Close", etc. requests to the FZD control unit. The roof control panel control unit sends appropriate CAN messages to the sliding/tilting sunroof control unit (via the K-CAN). Master for rain-light sensor or rain-light solar sensor The FZD control unit provides the rain-light sensor or rain-light solar sensor a bus connection to the K-CAN. This enables the following messages and requests to be sent: Switch position of the wiper switch or button for intermittent operation, depending on the rain-light sensor or rain-light solar sensor Position of the thumbwheel for setting the sensitivity of the rain-light sensor or rail-light solar sensor (selection of interval stage for rain sensor with wipers in intermittent operation) Status of wipers: The signal from the reset contact in the wiper motor is transmitted via the FZD control unit to the rain-light sensor or rain-light solar sensor. "Switch dipped-beam headlights on" prompt from rain-light sensor or rain-light solar sensor to footwell module: If the rain-light sensor or rain-light solar sensor detects that it is dark, the dipped-beam headlights will come on automatically (if the light switch is in switch position "A" = "Automatic driving lights control").
3. The FZD control unit in the roof control panel (High variant) is the data interface for the following components and functions: Gateway between K-CAN and LIN bus The FZD control unit is the data interface for the rain-light sensor or rain-light solar sensor between the K-CAN and the LIN bus. Gateway for condensation sensor The FZD control unit operates as a data interface for the condensation sensor as follows: The FZD control unit receives the signals from the condensation sensor via the interior mirror connector. The signals from the condensation sensor are pulse-width-modulated. The signals indicate the relative moisture on the inside of the windscreen. The FZD control unit converts the signals from the condensation sensor into digital messages for the K-CAN. The IHKA control unit receives these messages via the K-CAN. The demisting program is started accordingly. Gateway for Check Control The roof control panel issues Check-Control messages providing information about the sliding/tilting sunroof. Anti-trap circuit Loss of normalisation following mechanical actuation: If the sliding/tilting sunroof has been moved mechanically using the emergency actuating unit, the tilted end stop must be taught in again (normalisation). Gateway for the electrochromic interior mirror and for the electrochromic exterior mirrors The FZD control unit is the data interface between the electrochromic interior mirror, K-CAN and electrochromic exterior mirrors. The electrochromic exterior mirrors are controlled as follows when a request is sent via the electrochromic interior mirror: The electrochromic interior mirror sends a signal to the FZD control unit. The FZD control unit evaluates the signal and converts it into a percentage value (the percentage by which the exterior mirrors are to be dimmed). The FZD control unit sends this percentage value to the footwell module (FRM) via the K-CAN. The footwell module (FRM) sends the "Dim electrochromic exterior mirrors" request to the driver's door switch block. The driver's door switch block forwards the request to the electrochromic exterior mirror electronics. The electrochromic exterior mirrors are dimmed accordingly. For safety reasons, the electrochromic mirrors are not dimmed when reverse gear is engaged. If the vehicle has a manual transmission, the reverse-light switch will send a signal to the footwell module. The message is forwarded to the FZD control unit from the footwell module via the K-CAN. If the vehicle has an automatic transmission, the FZD control unit will receive the message "Reverse gear engaged" from the EGS control unit (via the K-CAN). (EGS: Electronic transmission control; SMG: Sequential manual transmission) The electrochromic mirrors are not dimmed until the reversing manoeuvre has been completed.

The FZD control unit is active under the following conditions

1. Terminal R ON, or
2. Terminal 15 ON and
3. K-CAN active

If none of these 3 conditions is met, the FZD control unit will switch to sleep mode and can be woken up by pressing the buttons for the interior lighting.

This section describes

1. How to switch the interior lighting on and off
2. How to set the sensitivity of the rain-light sensor or rain-light solar sensor

How to switch the interior lighting on and off

The interior lighting is switched on and off using 3 buttons

1. Interior-light button: The interior-light button switches both the front-compartment interior lights and the rear compartment interior lights on and off.
2. Button for reading light on driver's side and button for reading light on passenger side

The button only ever switches the reading lamp on that side on and off.

Setting the sensitivity of the rain-light sensor or rain-light solar sensor

The rain-light sensor consists of a driving light sensor and a rain sensor.

The rain-light solar sensor comprises a driving light sensor, a rain sensor and a solar sensor

The driving light sensor measures the surrounding brightness outside the vehicle. Depending on the sensitivity of the driving light sensor, the dipped headlight will come on at dusk or when it goes dark ("Automatic driving lights control" option).

The sensitivity of the driving light sensor can be set as follows

1. On vehicles without CID (Central Information Display) On vehicles without CID (Central Information Display), the sensitivity of the driving light sensor is encoded via the BMW diagnosis system.
2. On vehicles with CID (Central Information Display): The sensitivity of the driving light sensor can be set directly in the vehicle using the controller (in the Central Information Display).

Japanese national version

The roof control panel creates the earth connection for the interior mirror with electronic toll function.

Subject to change.

In September 2002, the first so-called VRLA batteries, better known as AGM batteries came into use. (VRLA means valve-regulated lead acid, i.e. lead acid battery with pressure relief valve; AGM stands for absorbent glass mat, i.e. absorbent glass-fibre fleece)

AGM batteries are installed in models with electrical consumers that have high energy requirements.

Depending on the equipment fitted on the vehicle, AGM batteries (90 Ah) are currently installed in the following development model series

1. E39
2. E46
3. E53
4. E60, E61, E63, E64
5. E65, E66
6. E70
7. E81, E87, E90, E91, E92, E93
8. R56

AGM batteries will be fitted as standard as part of CO2 measures (e.g. intelligent alternator regulation or automatic engine start/stop system).

The continuously increasing energy requirements of modern vehicle electrical systems demands ever more efficient battery solutions. A modern luxury-class vehicle has some 100 actuator motors that have to be fed with electrical current.

Then there are the safety, environmental and convenience elements, which are increasingly becoming standard, for example

1. Anti-lock brake system (ABS)
2. Dynamic Stability Control (DSC)
3. Electro-mechanical power steering (EPS)
4. Heated catalytic converter
5. Electronic chassis control
6. Air conditioning system
7. Navigation system

Current consumption is considerable even when the vehicle is not in use.

The slightly higher price and greater weight for the same size battery are fully compensated for by the following benefits

1. greatly longer service life
2. improved starting reliability at low temperatures
3. reliable starting of engines with high starting current requirements, e.g. high-performance diesel engines
4. 100% maintenance-free
5. low risk in the event of an accident (reduced environmental risk)

Scheme 1091

ITEM DESCRIPTION

In contrast to conventional lead-calcium batteries, the sulphuric acid in a battery with fleece technology is not held freely in the battery housing.

Rather, 100% of the sulphuric acid is bound into the mats of the glass-fibre fleece (separators). For this reason, no acid can escape if the battery housing is damaged. In addition, the AGM battery is sealed to be airtight. This is possible because the gases are converted back into water by the permeability of the separators.

AGM batteries can be recognised by the black housing and the lack of the so-called "magic eye".

Scheme 1092

1. E60, E61 from 03/2007

The BMW 5 Series can be equipped with a fully automatic trailer coupling (option 3AC "trailer coupling with electrically pivoted ball head").

The fully automatic trailer coupling (system supplier Westfalia) is operated by a button in the luggage compartment. Briefly pressing the button prompts the ball head to pivot out or in as far as each limit position entirely automatically. The system has a control unit that is not directly connected to the vehicle's bus system.

The BMW 3 Series can be equipped with an electrically released trailer coupling (option 3AC "trailer coupling with pivoted ball head").

The trailer coupling is released by a button in the luggage compartment.

The trailer coupling has a pivoted ball head. The trailer coupling release can be operated when the ball head is folded in or out. The ball head then moves down to an intermediate position.

The trailer coupling must be manually locked, and heard to lock, in both end positions.

The system has a control unit without a direct connection to the vehicle's bus system.

Modifications from 09/2005

From 09/2005, the E91 is available with option 3AC. Since this time, a separate Check Control symbol has been provided for the system. In the event of a system error, the trailer module will generate a Check Control message. The Check Control message appears in the instrument cluster.

The separate loudspeaker is discontinued.

Modifications from 03/2007

To coincide with the new model appearing in 03/2007, the E60, E61 is equipped with option 3AC "trailer coupling with electrically pivoted ball head"). Since this time, a separate Check Control symbol has been provided for the system. In the event of a system error, the trailer module will generate a Check Control message. The instrument cluster displays the Check Control message.

The following components supply signals for the electric trailer coupling release or fully automatic trailer coupling

1. Button for the trailer coupling release E90, E91, E92, E93 Pressing the button operates the trailer coupling release. The ball head moves from the locked position to an intermediate position. Two coloured LEDs are integrated into the button (green and red). The indicator lamp shows the system status. While the ball head is not locked, the indicator lamp in the button will light up red.
2. Button for the electrically pivoted trailer coupling E60, E61 Pressing the button prompts the ball head to pivot out or in as far as each limit position. Two coloured LEDs are integrated into the button (green and red). The indicator lamp shows the system status. While the ball head is not locked, the indicator lamp in the button will flash red.
3. Rear-lid contact switch The rear lid must be open when the trailer coupling is operated. The rear lid contact switch in the rear lid lock transmits the signal to the control unit for the trailer coupling release (E90, E91, E92) or for the electrically pivoted trailer coupling (E60, E61). At the same time, the luggage compartment lights are switched on by this contact.
4. Microswitch in drive for trailer coupling release E90, E91, E92, E93 The microswitch is a switch with 3 connections. The microswitch recognises whether the ball head is locked in one of its two end positions (folded out or folded in). The microswitch transmits the signal to the trailer coupling release control unit.
5. Microswitch for trailer detection E60, E61 The microswitch for trailer detection is built into the trailer socket. If the trailer connector is inserted in the trailer socket, the ball head cannot be pivoted in.
6. Hall-effect sensor in drive system for the electrically pivoted trailer coupling E60, E61 The Hall-effect sensor is integrated into the drive system. The entire pivoting travel of the ball head is monitored with the aid of the Hall-effect sensor. The drive system's rotary movement is transmitted by the Hall-effect sensor to the control unit for the electrically pivoted trailer coupling in the form of a Hall-effect sensor signal. In parallel to the Hall-effect sensor signals, the control unit measures the current required for the pivoting movement. If the permissible current consumption of the DC motor is exceeded during fully automatic pivoting out or in, or no Hall-effect sensor signals are emitted, the ball head's pivoting movement is halted. The ball head is pivoted back a short way in the opposite direction (reversed).
7. Loudspeakers E90 up to 09/2005 The loudspeaker is located on the left under the rear window shelf. An acoustic signal is emitted when the ball head is unlocked. The loudspeaker indicates a Check Control message with a continuous tone. The loudspeaker is actuated by the trailer coupling release control unit.

Several control units are involved in the trailer coupling release

1. Control unit for the trailer coupling release or electrically pivoted trailer coupling E60, E61: Control unit for the electrically pivoted trailer coupling E90, E91, E92, E93: Trailer coupling release control unit The control unit energises the drive system's direct current motor. The control unit is not directly connected to the bus system. The control unit is not capable of self-diagnosis, nor can it be programmed.
2. CAS: Car access system The CAS control unit supplies the input signal for the status of terminal 15 at the control unit for the trailer coupling release (E90, E91, E92, E93) or for the electrically pivoted trailer coupling (E60, E61). With terminal 15 ON, the trailer coupling cannot be released or pivoted out or in.
3. AHM: Trailer module The trailer module is directly connected to the control unit for the trailer coupling release (E90, E91, E92, E93) or to the control unit for the electrically pivoted trailer coupling (E60, E61). In the event of a system error, the trailer module will generate a Check Control message. The trailer module furthermore serves as a trailer detector. The trailer module identifies a trailer as connected if at least 2 loads (cold measurement) are detected at the lighting output terminals. The trailer module then transmits the message "Trailer connected" along the K CAN. This message is translated by several control units in the towing vehicle. For instance, the ultrasonic sensors at the rear of the towing vehicle are deactivated via Park Distance Control. The footwell module (E90, E91, E92, E93) or lights module (E60, E61) deactivate the rear fog light and reversing light on the towing vehicle.

Other components

1. Power distributor in junction box E90, E91, E92, E93 The electrical distribution center in the junction box supplies power to the trailer coupling release control unit (terminal 30g). The junction box consists of the junction box electronics (JBE) and electrical distributor.
2. Front and rear electrical distributors E60, E61 The front electrical distributor supplies the control unit for the electrically pivoted trailer coupling with power (terminal 30). The control unit for the electrically pivoted trailer coupling receives the input signal "terminal 30g" from the rear electrical distributor.

The following components are controlled

1. Drive system for the electrically pivoted trailer coupling E60, E61 The drive system pivots the ball head out and in fully automatically as far as each limit position.
2. Trailer coupling release drive E90, E91, E92, E93 The drive mechanically releases the trailer coupling ball head. This is done by a DC motor being actuated, which drives the trailer coupling release unit.
3. Light-emitting diode in the button for the electrically pivoted trailer coupling and for the trailer coupling release The indicator lamp shows the system status.
4. Instrument cluster The instrument cluster is actuated in the event of a Check Control message from the trailer module (AHM).

The following system functions of the trailer coupling release and electrically pivoted trailer coupling are described

1. Releasing the trailer coupling (E90, E91, E92, E93)
2. Pivoting the electrically pivoted trailer coupling out and in (E60, E61)
3. Monitoring of terminal 15 and Check Control message
4. Undervoltage and overvoltage
5. Overheating protection for the drive system (E90, E91, E92, E93)
6. Adjusting the trailer coupling (E60, E61)
7. Emergency function (E60, E61)
8. Emergency operation (E90, E91, E92, E93)

Trailer coupling release

1. E90, E91, E92, E93

The trailer coupling can be released from terminal 30g ON. The following signal conditions must be satisfied to allow the coupling to be released

1. Terminal 30g: high signal
2. Button: low signal
3. Terminal 15: low signal
4. Rear lid contact switch: low signal
5. Microswitch output 1: low signal
6. Microswitch output 2: high signal

The control unit for the trailer coupling release uses the signal conditions to check whether the release procedure can be started. The DC motor is actuated. During release, the outputs at the microswitch change the signal conditions. The indicator lamp lights up red.

While the trailer coupling is released, the loudspeaker emits a continuous tone (E90 to 09/2005) or an acoustic signal is given for a limited time (E90 from 09/2005, E91, E92, E93).

When the trailer coupling is locked in the end position (manually), the outputs at the microswitch change the signal condition again. The indicator lamp lights up green. The loudspeaker is deactivated (E90 up to 09/2005).

Pivoting out and in of the electrically pivoted trailer coupling

1. E60, E61

The trailer coupling can be pivoted electrically from terminal 30g ON. The following signal conditions must be satisfied to allow the coupling to be pivoted electrically

1. Terminal 30g: high signal
2. Button: low signal
3. Terminal 15: low signal
4. Rear lid contact switch: low signal
5. Microswitch for trailer detection: high signal

The control unit for the electrically pivoted trailer coupling uses the signal conditions to check whether the pivoting movement can be started.

If the activation conditions are met, the following procedures can be performed by pressing the button for the electrically pivoted trailer coupling

1. Automatic pivoting out or in (single brief press of button)
2. Pivoting out or in by continuous operation of button

Automatic pivoting out and in

Briefly pressing the button (for less than 1 second) pivots the ball head fully automatically from one limit position to the other.

Fully automatic pivoting out or in can be halted at any time by briefly pressing the button a further time.

Fully automatic pivoting out or in can only be started if the ball head is in one of the two limit positions or fully automatic pivoting out or in has been halted by pressing the button.

Reversing the pivoting movement

If the permissible current consumption of the DC motor is exceeded during fully automatic pivoting out or in (e.g. as a result of an obstruction, stiff movement or low ambient temperatures), the control unit for the electrically pivoted trailer coupling triggers reversing. The ball head's pivoting movement is halted. The ball head is pivoted back a short way in the opposite direction (reversed).

It can now only be moved by continuous operation of the button (manual operation).

Reversing is suppressed close to either limit position and a higher current consumption is permitted. This allows the ball head to be pivoted out of each limit position with more force (e.g. to release the ball head if stuck).

Pivoting out or in by continuous operation of the button

This mode is entered by pressing the button for the electrically pivoted trailer coupling for longer than 1 second. The ball head is only pivoted for as long as the button is pressed. If the button is held pressed, the ball head is pivoted in the opposite of its previous direction of pivoting. The ball head's pivoting movement stops when the button is released. A further pivoting movement can only be performed in this mode.

Increased current consumption by the DC motor is permissible in the continuous button-operated mode. If the current consumption permissible in this mode is exceeded, the ball head's pivoting movement stops. The ball head does not pivot in the opposite direction to its previous direction of pivoting (no reversing in this mode).

Only if a limit position is reached in this mode is automatic pivoting out or in possible again

Monitoring of terminal 15 and Check Control message

1. E60, E61

The CAS transmits a status signal for terminal 15 to the control unit for the electrically pivoted trailer coupling. The control unit transmits the status signal and the operating statuses of the trailer coupling to the trailer module (AHM).

The CAS also transmits the status signal for terminal 15 to the trailer module via the K CAN. The plausibility of both signals is checked in the trailer module.

Signals from the control unit for the electrically pivoted trailer coupling to the AHM

1. Status signal of terminal 15 OFF: low signal
2. Status signal of terminal 15 ON and pivoting ball head in limit position: PWM signal (pulse-width-modulated signal) 450 ms low -> 50 ms high -> 450 ms low -> etc.
3. Status signal of terminal 15 ON and ball head pivoting or halted in intermediate position: high signal

The trailer module generates a Check Control message. The Check Control message is sent via the K CAN. The Check Control message is only indicated after the engine is restarted by a Check Control symbol (red) in the instrument cluster and by an acoustic signal of limited duration (E90 up to 09/2005: continuous signal).

Check Control message

1. Trailer coupling locked or
2. Trailer coupling electrics

Further information is provided in the Central Information Display (CID).

1. E90, E91, E92, E93

Terminal 15 is monitored by a live signal as follows

1. Terminal 15 ON and trailer coupling locked: The trailer coupling release control unit transmits the live signal to the trailer module (AHM). To do this, the control unit activates the output to the AHM every 450 ms.

The trailer module detects a system error by the absence of the live signal.

1. E90 up to 09/2005

A yellow Check Control symbol in the instrument cluster indicates the Check Control message: Vehicle on lifting platform. The loudspeaker simultaneously emits a continuous signal.

If the trailer coupling is released with terminal 15 ON, a Check Control message is likewise generated. The loudspeaker is switched on for 30 seconds.

The output to the AHM has a high resistance when terminal 15 is OFF.

1. E90/E91 from 09/2005 and E92, E93

From 09/2005, a separate, unambiguous Check Control symbol has been provided for the trailer coupling release.

Undervoltage and overvoltage

1. E60, E61

The electrically pivoted trailer coupling control unit detects undervoltage and overvoltage.

Undervoltage On-board supply voltage less than 9 volts

Overvoltage On-board supply voltage greater than 16 volts

If overvoltage or undervoltage is detected during fully automatic pivoting in or out of the ball head, the ball head still pivots as far as the limit position. The error is then indicated via the LED in the pushbutton.

If an overvoltage or undervoltage is detected during continuous operation of the button for the electrically pivoted trailer coupling, the ball head can still be pivoted into the limit position. The ball head's pivoting movement stops when the button is released. The DC motor can then no longer be energised while the overvoltage or undervoltage persists.

1. E90, E91, E92, E93

The trailer coupling release control unit detects undervoltage and overvoltage.

Undervoltage On-board supply voltage less than 9 volts

Overvoltage On-board supply voltage greater than 15 volts

Outside this voltage range, the system is deactivated.

Overheating protection for drive

1. E90, E91, E92, E93

The DC motor is actuated for a maximum of 4 seconds.

The control unit detects an excessively high current draw for the drive, e.g. due to blocking. The maximum current draw is 13 amps.

Adjusting the trailer coupling

1. E60, E61

To ensure that the trailer coupling remains pivoted in the limit position, the DC motor is energised briefly in the direction of the limit stop every 60 seconds.

The control unit for the electrically pivoted trailer coupling activates adjustment in the following conditions

1. Terminal 15 ON
2. Ball head pivoted out in limit position

Emergency function

1. E60, E61

Cyclical readjustment of the pivoted-out ball head can result in the ball head becoming mechanically jammed in this limit position.

In this event, the ball head can be freed from the limit stop by the emergency function.

A defined pivoting movement must be achieved in the run-up phase to pivoting the ball head out or in. This pivoting movement corresponds to a defined number of Hall-effect pulses by the DC motor. The Hall-effect pulses are picked up by a Hall-effect sensor on the DC motor.

If a defined number of Hall-effect pulses is not reached, the control unit activates the emergency function.

In the emergency function, the DC motor is energised five times cyclically (each cycle comprises energising for 300 ms followed by a pause of 200 ms).

If the minimum number of Hall-effect pulses is not achieved, the ball head can then only be pivoted in or out by continuous operation of the button for the electrically pivoted trailer coupling.

The control unit for the electrically pivoted trailer coupling activates the emergency function in the following conditions

1. Briefly pressing (for less than 1 second) the button for the electrically pivoted trailer coupling (mode: fully automatic pivoting out or in)
2. Trailer head is in the run-up phase to pivoting in or out
3. Emergency function was not previously triggered
4. Minimum number of Hall-effect pulses by the DC motor not achieved

Emergency operation

1. E90, E91, E92, E93

If the power supply is interrupted during operation, various signal conditions could be lost.

When power is available again, the button must be pressed and held for 5 seconds. This will switch the drive on (emergency operation).

If the power supply is interrupted, the trailer coupling cannot be released.

The following switch-on conditions for the trailer coupling release or electrically pivoted trailer coupling must be met

1. Terminal 15 OFF
2. Rear lid open
3. No overvoltage or undervoltage in the on-board supply voltage

1. E60, E61 with ball head pivoted out

1. Trailer connector not inserted in trailer socket

Scheme 1093

From a functional point of view, central locking system on the BMW 1-Series and 3-Series is divided among several control units. The Car Access System (CAS) monitors all the processes in the central locking system. The CAS control unit is the master control unit for the central locking system.

The control units for the central locking system are

1. Car Access System (CAS)
2. Footwell module
3. Junction box electronics (JBE)

The CAS control units use the prompts from various operating points (e.g. lock cylinder, remote control, comfort access) to decide what needs to be done

1. Locking/deadlocking the central locking system
2. Unlocking the central locking system

The following components supply an input signal for the central locking system

1. Door lock cylinder The door lock cylinder allows manual locking/deadlocking and unlocking of the vehicle. If the vehicle electrics should fail, the driver's door can be unlocked manually with the key (mechanical key element in the remote control).
2. Door contacts The signals from the Hall sensors in the door contacts are evaluated by the footwell module (FRM). The antitheft alarm system (DWA), for instance, requires the signals for the purpose of monitoring the doors.
3. Remote control The remote control allows the vehicle to be locked/deadlocked via radio (aerial interface). The radio signals from the remote control are received by the FBD receiver (receiver for remote control) and transferred to the CAS control unit. E87, E93 The remote control receiver is integrated in the interior mirror. E90, E91, E92 The remote control receiver is integrated in the aerial amplifier.
4. Central locking button The central locking button allows the vehicle to be locked/unlocked from the passenger compartment. The fuel filler flap is not locked. E93 The glove compartment and the stowage compartment in the centre console are not locked.
5. Hotel position switch (US version) E90, E92, E93 The hotel position switch is installed in the glove box. The hotel position switch decouples the tailgate from the central locking system. When hotel position is selected (locked or unlocked), the setting of the hotel position switch is detected.
6. Interior tailgate switch (US version) The interior tailgate switch on the A-pillar in the driver's footwell allows the tailgate to be opened when the vehicle is unlocked and stationary (hotel position not selected).
7. Exterior tailgate switch The exterior tailgate switch allows the boot lid to be opened while the vehicle is unlocked and stationary (hotel position not applied). E87 Opening tailgate with BMW logo.
8. Boot lid lock E90, E92, E93 The tailgate lock allows the tailgate to be mechanically opened (hotel position not selected).
9. Rear window button E91 The rear window button can be used to open the rear window if the vehicle is unlocked and stationary. The rear window switch is integrated in the rear window wiper.

The following control units are involved in the central locking system

1. CAS: Car Access System All the rules for controlling the central locking are integrated in the CAS control unit. The commands are sent via the K CAN.
2. JBE: Junction box electronics The junction box electronics unit is the executing control unit for the central locking system. The The junction box electronics assume the task of actuating all central-locking system drives. The junction box consists of the junction box electronics and the electrical distribution centre. The junction box is fitted underneath the glove box.
3. FRM: Footwell module The footwell module evaluates the status of the Hall sensors in the door contacts. When the vehicle is locked or unlocked with the mechanical key element, the footwell module will recognise this request. The footwell module transmits a message on the K-CAN to the CAS control unit (CAS: Comfort Access System). The footwell module is fitted at the bottom of the A-pillar in the footwell on the driver's side.

The following actuators are controlled by the central locking system

1. Door lock The door locks comprise: 2 drives with gearing Hall sensors as door contact
2. Drives in the door locks There are 2 drives in each door lock. The locking mechanism can be brought into the following position by the drives: Lock: door can still be opened from the inside Deadlock: door cannot be opened from the inside or from the outside Unlock: door can be opened from the inside and outside
3. Drive for fuel filler flap The drive locks/unlocks the fuel filler flap.
4. Drive for the boot lid lock The drive unlocks the boot lid.
5. Drive for rear window lock E91 The drive unlocks the rear window.
6. Drive for electrically locking glove compartment E93 If central locking is activated vie the central locking system, the door lock cylinder or Comfort Access (CA), the drive will block the glove compartment opener. In this situation, it is only possible to open the glove compartment with the mechanical key. If the glove compartment was locked with the mechanical key, it can only be opened again with the mechanical key.
7. Drive for electric locking of stowage compartment in centre console E93 The drive locks the stowage compartment in the centre console. If the battery is flat or defective, the stowage compartment in the centre console can be opened with a cable.
8. Unlocking drive for roller cover E91 There is an unlocking drive on the left and right-hand sides of the D-pillar. To unlock the roller cover, the unlocking drivers are actuated for about 2 seconds by the junction box electronics.

The central locking system incorporates the following functions

1. Locking
2. Deadlocking
3. Unlocking
4. Hotel position
5. Crash unlocking
6. Forced deadlock release
7. Lockout protection
8. Repeat lock
9. Automatic relocking
10. Voltage monitoring
11. Selective unlocking
12. Speed-dependent locking
13. Locking the fuel filler cap

Locking

A locked door cannot be opened from the outside. However, the door can still be opened from the inside. To do this, the door handle must be pulled twice.

Locking is performed in the following ways

1. Operation of the central locking button (condition: front doors must be closed)
2. Operation via the driver's door lock cylinder or the remote control, where the conditions for deadlocking are not fulfilled (see " «DEADLOCKING»(/bmw/m3/e90-2007-2013/remont/door-locks-anti-theft-systems/#general-electrical-system-service-techniques__deadlocking) ").
3. Driver's door closed

Deadlocking

A locked and secured door cannot be opened either from the inside or outside.

The doors are secured when the driver's door is locked via the locking cylinder (only in conjunction with DWA or CA on the BMW 1-Series) or with the remote control.

Conditions

1. Terminal R OFF
2. Driver's door or front-passenger door was opened
3. Driver's door closed

When the vehicle is deadlocked, the anti-theft alarm DWA is also primed.

Unlocking

An unlocked door can be opened from the inside and the outside.

When the vehicle is unlocked, the anti-theft alarm (DWA) is also deactivated.

Hotel position (US version)

When the hotel position is selected, the boot lid also stays locked after the vehicle is unlocked. For hotel position to be selected, the setting of the hotel position switch is detected.

Crash unlocking

A crash is recognised as such by the MRS control unit (E87, E90, E91, E92) or ACSM control unit (E93). A crash signal is transmitted by the CAS control unit. The message is sent on the K-CAN. The CAS control unit unlocks the vehicle.

All operating points are disabled when there is a crash signal. This prevents unintentional actions of the central locking system from occurring due to short circuits caused by the accident.

After a crash, the central locking system cannot be operated until terminal R has been switched off for at least 3 seconds.

(MRS = "Multiple Restraint System"; ACSM = "Advanced Crash Safety Module", alternatively known as the "Crash Safety Module")

Forced unlocking

When the CAS detects that a remote control is locked in place in the slot, the central locking system is released. The central locking system adopts the "Locking" position.

The anti-theft alarm is also deactivated during forced release.

Lockout protection

To protect the driver against unintentionally locking himself out, all operating points are locked when the driver's door is open. This makes any additional mechanical lockout protection in the door locks unnecessary.

Repeat interlock

To protect the central locking drives (doors, tailgate, fuel filler flap, rear window, glove compartment and stowage compartment in the centre console) against overloading, the CAS monitors repeat operation.

If there are more than 15 attempts at activation within one minute, the drives are not unlocked for a certain time.

Automatic relocking

If the central locking system is unlocked using the remote control and no door or boot lid is opened within 2 minutes, the vehicle is automatically locked again (locked and secured).

This function can be activated via the personal profile.

Voltage monitoring

The function range for the central locking system is specified as being from 9 to 16 volts. Outside this range, the drives will not be actuated.

If the power supply is interrupted, the status of the central locking system will not change (anti-theft protection).

Selective unlocking

The first time there is an unlocking command, only the driver's door is unlocked. The central locking system sets all other doors from deadlock to lock. The anti-theft alarm system is switched off and the doors remain locked. The second time there is an unlocking command, the remaining doors are unlocked.

This function can be activated via the personal profile (depends on national version concerned).

Speed-dependent locking

The central locking system is automatically locked from a speed of approx. 16 km/h.

This function can be activated in the Personal Profile (depends on national version concerned).

Locking the fuel filler cap

The fuel filler flap is only locked when the central locking system is set to deadlock.

This function can be activated in the Personal Profile (depends on national version concerned).

The following details are available with regard to national versions

1. US The glove compartment is electrically locked. Reason: Knee airbag fitted in glove compartment lid. In order to transmit the forces that are released when the airbags are triggered, the glove compartment lid is bolted on both sides when it is closed. When the opener is lifted slightly to open the glove compartment, a microswitch transmits a signal to the junction box electronics (JBE). The JBE briefly actuates the unlocking drive in the glove compartment. The unlocking drive retracts the 2 locking bolts. The glove compartment lid can then be opened again. After a short time, the unlocking drives are de-energised and the locking bolts extend again. The locking bolts have an angled area at the end. This has the effect of mechanically pushing the locking bolts onto a spring when the glove compartment lid is closed. When the glove compartment lid is closed, the spring pushes the locking bolts back out, locking the glove compartment.

Subject to amendment arising from errors, misprints and technical modifications.

Scheme 1094

On the BMW 1-Series, the instrument cluster has an analogue display for

1. Speed
2. Speed
3. Fuel level

On the BMW 3-Series, the instrument cluster has an analogue display for

1. Speed
2. Speed
3. Fuel level
4. Fuel-consumption indicator
5. Cruise control with moving-disc instrument for: Cruise control with brake function (option 544) Active cruise control (option 541)

The scales on the instrument cluster depend on the country concerned and the engine installed. All indicator and warning lights that are stipulated by law are located between the two large pointer instruments.

Under the two large pointer instruments there is an LCD display (e.g. for Check-Control message symbols).

New for the instrument cluster, gradual introduction from 03/2007 (depending on engine version)

1. Shift point indicator
2. Additional Check-Control messages for automatic engine start/stop system

On vehicles with multi-audio system controller (M-ASK) or Car Communication Computer (CCC)

Various displays appear in parallel on the Central Information Display (CID), e.g. information concerning CBS or Check Control.

The following components deliver signals to the instrument cluster

1. Outside temperature sensor The outside temperature sensor is connected to the junction box electronics (JBE). Wires lead from the JBE to the instrument cluster. The outside temperature is displayed on the LCD display in the instrument cluster. When terminal 15 is OFF, the outside temperature sensor will continue to measure the temperature for a maximum of 24 hours. The signal from the outside temperature sensor is digitised in the instrument cluster. A computation model compensates for the effect of the residual heat from the engine compartment on the signal. A lower damping value is set at higher speeds or low engine temperatures. The true outside temperature can only be reliably expected from a roadspeed of about 80 km/h.
2. SZL: Steering Column Switch Two switches are located on the turn-signal/main-beam switch on the steering column switch cluster (SZL): an axial switch and a rocker switch. The following contents can be called up with the two switches and shown on the LCD display in the instrument cluster: On-board computer functions and Check-Control confirmation Menu for the following functions (display is encoding-dependent, also in CCC or M-ASK, depending on equipment fitted): Dim instrument illumination Scroll Check-Control message Check engine oil level Run Flat Indicator initialisation Set time Set date CBS settings Personal Profile settings
3. FRM: Footwell module The footwell module (FRM) controls the interior and exterior lighting. From the footwell module, information is sent through the K-CAN, e.g. whether or not the indicator and warning lights stipulated by law need to be actuated.
4. JBE: Junction box electronics or junction box The junction box electronics send the following signals to the instrument cluster: Coolant level (Check-Control message) Washer fluid level (Check-Control message) Fuel level via 2 fuel level sensors (used by instrument cluster to compute the Check-Control message) Parking brake applied (general brake warning lamp) The junction box is also the gateway between the PT-CAN and the K-CAN. The PT-CAN is used, e.g. for DME/DDE and DSC messages. The K-CAN is used, e.g. for terminal control signals from the CAS control unit. The instrument cluster receives its power supply from the junction box terminals 30 and 31.
5. MRS: Multiple restraint system The multiple restraint system (MRS) is a bus participant on the K-CAN. The MRS control unit sends the message whether the airbag warning light or seat belt indicator light needs to be actuated.
6. DME or DDE: Digital engine electronics or digital diesel electronics The DME/DDE supplies the following signals (for example) to the instrument cluster: Engine speed and injection rate. The message is sent through the PT-CAN and then through the K-CAN. The DME/DDE also indicates whether an exhaust-related fault has developed (actuation of emissions warning light). On vehicles from 03/2007 Depending on the engine version installed, an automatic engine start/stop system may be fitted. The engine management controls this function. If a fault develops in the automatic engine start/stop system, the engine management will generate a corresponding Check-Control message. The instrument cluster displays the Check-Control message.
7. DSC: Dynamic Stability Control The brake pad wear sensors are connected to the DSC control unit. The DSC also sends further messages to actuate indicator and warning lights in the instrument cluster: ABS indicator and warning light. DSC indicator and warning light. DTC indicator light. General brake warning light
8. EGS: Electronic transmission control On vehicles with automatic transmission: A signal from the EGS control unit causes the gear program display or gear indicator in manual mode to be shown in the LCD display. On vehicles with manual transmission: No gear indicator. The area is used (via encoding) for a larger on-board computer function display.
9. Cruise control with brake function or active cruise control On vehicles with 6-cylinder engine and longitudinal dynamic management (LDM control unit): The set speed is transmitted by the LDM control unit to the instrument cluster on the PT-CAN and K-CAN. During active cruise control, an additional indicator light is activated as a distinguishing feature for cruise control with brake function. The distance to the vehicle in front is indicated with 3 bars. The set speed for active cruise control appears briefly in the LCD display (in addition to permanent display with the moving-disc instrument). BMW 3-Series: On vehicles from 06/2006, cruise control with brake function is integrated into DSC. These vehicles then only have an LDM control unit if active cruise control is fitted.
10. Body CAN The instrument cluster receives all other messages that could mean a display in the instrument cluster (e.g. Check- Control messages) through the body CAN (K-CAN).

The instrument cluster comprises the following system functions

1. Operational readiness
2. Operating voltage range
3. Brightness control
4. Actuation for moving-disc instrument
5. Shift point indicator
6. Redundant data storage

Operational readiness

Operational readiness depend on the terminal.

1. Terminal 30 The instrument cluster is connected to terminal 30 via the junction box. The terminal status (terminal R or terminal 15) is sent to the instrument cluster via the K-CAN. If terminal 30 is active (terminal R OFF), the instrument cluster is in standby mode. The instrument cluster can be activated by pressing the reset button - the following are then displayed: distance recorder, clock, outside temperature, fuel level (can be encoded). The display goes out after 25 seconds.
2. Terminal R The following are evaluated when terminal R is switched ON: turn-signal/main-beam switch and fuel level sensor. The time and outside temperature appear in the LCD display. The on-board computer functions can be called up via the on-board computer button (display unlimited).
3. Terminal 15 When terminal 15 is switched ON, a pre-drive-check is carried out on the permanent indicator and warning lights. The display elements show the current figures, e.g. fuel level.
4. Terminal 50 (starter motor) While the engine is being started, the on-board supply voltage may drop so far that the internal voltage supply (6 volts) can no longer be maintained. In this case, no analogue signals can be evaluated. Moreover, no data will be able to be stored (in EEPROM).

Operating voltage range

The operating voltage range is from 9 to 16 volts. If the voltage drops below 7.5 volts, undervoltage will be recognised. If the voltage rises over 16 volts, no analogue inputs can be evaluated.

Brightness control

The instrument cluster is illuminated when the lights are switched ON.

A phototransistor is installed in the instrument cluster to calculate the necessary brightness (display, indicator and warning lights, scales, needles).

The brightness value calculated in the instrument cluster is output on the K-CAN (e.g. for the Central Information Display).

Dimming can be set individually via a menu in the instrument cluster.

When the vehicle lighting is switched on, these individual settings and the phototransistor are used to control the dimming.

When the vehicle lighting is switched off, the dimming is only controlled by the phototransistor (display brightness according to ambient light).

Actuation for moving-disc instrument

The moving-disc instrument for the set speed is driven by a stepper motor.

The signal for the set speed is transmitted on the bus by the control unit for longitudinal dynamic management (LDM). This signal is converted to control pulses for the stepper motor.

The set speed is transmitted with a "resolution" of 1 km/h and displayed.

Shift point indicator

The shift point indicator is only available in conjunction with manual transmission.

A great deal of fuel can be saved by changing gear in good time. The shift point indicator assists the drive in this. The current driving situation is identified on the basis of roadspeed and vehicle acceleration. If the gear currently engaged is not the most economical, a gear change recommendation appears in the display. The shift point indicator can be activated and deactivated on the on-board computer. The shift point indicator is deactivated when the vehicle is delivered.

Redundant data storage

The following instrument cluster data are redundantly stored in the Car Access System (CAS)

1. Distance recorder
2. Trip meter
3. CBS data

This is conditional upon the same vehicle identification number being stored in both control units.

If different vehicle identification numbers are stored, the manipulation dot will appear in the LCD display.

The instrument cluster and the CAS must not be replaced at the same time. CBS data would then be lost.

Scheme 1095

iDrive was introduced with the E65.

Due to the position of the screen and the controller as well as the operations logic, iDrive is the leading control system in vehicles.

iDrive was consistently developed for the E60 and the ranges which follow

Due to the increased number of functions in the vehicle, improvements were also made to the ergonomics. The menu structure contains 5 menus in contrast to the E65 which contains 8 menus.

iDrive is characterised by

1. clear differentiation and optimum layout of the driving area for driving and convenience
2. Calmer atmosphere inside the vehicle due to a reduced number of switches
3. straightforward, logical controls
4. ergonomic positioning and design of display and control elements
5. integrational approach: the front passenger has access to all convenience functions

iDrive is also employed on the new BMW 1-Series and 3-Series.

In conjunction with the Multi-audio system controller (M-ASK) or Car Communication Computer (CCC), there is a display for the iDrive.

On the BMW 1-Series the folding Central Information Display (CID) is located in the middle of the dashboard.

On the BMW 3-Series, the Central Information Display is fixed and integrated into the dashboard.

iDrive consists primarily of the following components

1. Central Information Display (CID) The CID is the central graphic display unit. A number of displays are available depending on the equipment fitted: CENTRAL INFORMATION DISPLAY CHART E60, E61, E63, E64, E90, E91, E92 CID colour 6.5 inch, fully integrated (combined with option 606 "Business navigation system" with arrow display) in conjunction with M-ASK CID colour 8.8 inch, fully integrated (combined with option 609 "Professional navigation system" with map view) in conjunction with CCC E87 CID colour 6.5 inch, folding (with option 606 "Business navigation system" with arrow display in conjunction with M-ASK) (with option 609 "Professional navigation system" with map view in conjunction with CCC) The Central Information Display is connected via a LVDS data line (Low Voltage Differential Signalling) to the M-ASK or CCC.
2. Controller with menu button The controller is the central control element for the Central Information Display or iDrive. The controller is located in the centre console behind the gear lever or, in the case of automatic transmission, the selector lever. The menu button is located behind the Controller (with CCC, two-part option: menu button and Push-to-talk button for voice recognition system). The controller is connected via the K-CAN to the M-ASK/CCC. The controller is operated in the same way as on the 7 Series by slide or turn and then press. The Controller always returns to its home position when released. The basic variant of the Controller, however, only has 4 sliding directions: forward, back, to the right and to the left. In the High version, the controller has 8 directions of movement for the following function: destination input using crosshairs.
3. Loudspeakers The loudspeakers output the audio signals from the M-ASK or the CCC, as applicable.

The control unit that manages the functions of iDrive depends on the vehicle equipment

1. M-ASK: Multi-audio system controller The M-ASK combines a number of functions in a single control unit, as follows: Audio system controller (ASK) Control unit for the Central Information Display Navigation system with DVD drive Aerial tuner
2. CCC: Car Communication Computer The CCC incorporates further functions at the top end of the range in the form of a control unit (e.g. voice recognition system). The M-ASK or the CCC generates the LVDS data (Low Voltage Differential Signaling) for graphical presentation on the Central Information Display.

The further development of the iDrive for the 5 Series, 6 Series and 1 Series comprises

1. revised menus
2. hierarchical structure of the menus
3. Additional orientation guides

Revised menus

The start menu consists of 4 menus.

The 4 menus on the Central Information Display are situated on intersecting axes in the same way as the 4 points of the compass (as viewed in the clockwise direction) as follows

1. Communication Slide the Controller forward (= "north"): e.g. functions such as telephone, short text message or BMW Assist
2. Navigation Slide the Controller to the right (= "east"): e.g. functions such as route, on-board information or address book
3. Entertainment Slide the Controller back (= "south"): e.g. functions such as radio, CD or TV
4. Climate Slide the Controller to the left (= "west"): e.g. functions such as air distribution or heat distribution for seats

There is also an additional fifth menu for selecting the individual user presets.

1. Settings (i= Information) Press Controller in the start menu: e.g. functions such as "Settings for entertainment", "Settings for display" and "Settings for vehicle"

The start menu will always appear when the menu button behind the controller is pressed.

Exceptions to this are the submenus in menu 5: When the Controller is pressed, menu 5 "Settings" is initially called up. If the controller is pressed once more, the start menu is called up.

Hierarchical structure of the menus (operating logic)

The operating logic has a strictly hierarchical menu structure.

1. Displaying the menu path The current position in the menu structure can be seen by displaying the menu path (list of menu items selected to date in the individual menu lines, reading from top to bottom).
2. Navigating through the menus Slide the Controller to switch from one menu to another. Sliding the Controller forward means: Go one level higher in the menu hierarchy. Sliding the Controller to the rear means: Go one level lower in he menu hierarchy. In split-screen mode, sliding the Controller to the right selects the assistance window. Slide the Controller to the left to exit the assistance window (assistance window displays additional information).
3. Changing the settings If you want to change settings or view them in the submenus, turn the controller and press it down.

Additional orientation guides

The following features provide visual orientation in the menus

1. Orientation by special background colours Each menu has a background colour of its own. Communication = blue Navigation = green Entertainment = orange Climate = red Settings = grey The associated submenus also have the same background colour. This makes assignment of the submenus straightforward.
2. Orientation by position indicator A small, coloured symbol for each of the 4 menus appears in the top menu line: A diamond. The 4 corners of the diamond correspond to the 4 directions of the menus. A small square indicates the corner corresponding to the currently selected menu.
3. Status line for information at a glance The status line contains the most important information on the various functions, such as settings of the air conditioning system or the radio station currently selected. The start menu always appears when the menu button behind the controller is pressed.

The language package for the possible display languages is encoded at the end-of-line.

Subject to change.

Scheme 1096

The BMW 1-Series, 3-Series and X5 can be equipped with option 322 "Comfort Access".

This comfort system has been derived from the BMW 7-Series.

From 09/2005, Comfort Access will also be introduced to the BMW 5-Series and BMW 6-Series. The system has been taken from the BMW 3-Series, albeit with a few modifications.

With Comfort Access, an ID transmitter is needed instead of the usual remote control. The ID transmitter also performs standard remote control functions.

Comfort Access can be used to carry out the following functions

1. Passive Entry Opening the vehicle or luggage compartment without actively using the ID transmitter
2. Passive Go Engine start without actively using the ID transmitter
3. Passive Exit Closing the vehicle without actively using the ID transmitter

Comfort Access prevents an ID transmitter being disabled accidentally.

The CAS control unit is the master control unit for all functions carried out via Comfort Access. Vehicles with Comfort Access are fitted with a CA control unit.

New or modified features on E90, E91, E92 compared to E81, E87, E93

1. The detection range of the interior aerials has been modified as a consequence of the different vehicle design.
2. The remote control (FBD) receiver is integrated into the aerial amplifier. (> E81, E87, E93: FBD receiver integrated in interior mirror)

New or modified for the E60, E61, E63, E64

1. The outside door handle electronics is on the reverse of the door handle mounting bracket.
2. The CA control unit is installed in the carrier behind the glove compartment.

The following components are described for Comfort Access

1. Interior and exterior aerials Different aerials are required for communication with the ID transmitter: Interior and exterior aerials The number of aerials depends on the model concerned: AERIALS MODEL SPECIFICATION Interior aerials E60 E61 E63 E64 E70 E81 E87 E90 E91 E92 E93 Front centre console x x x x x x x x x x x Rear centre console x x x x x x x x x x x Rear window shelf (parcel shelf) x - x - - - - - - - - Back of rear seat - x - - - - - - - - - Luggage compartment, middle x - x x - x x x x x x Luggage compartment, right - - x x x - - - - - - Luggage compartment, left - - - - x - - - - - - Luggage compartment, load edge - x - - - - - - - - - Exterior aerials E60 E61 E63 E64 E70 E81 E87 E90 E91 E92 E93 Rear bumper, left x - x x - - - - - - - Rear bumper, middle - x - - x x x x x x x Outside door handle electronics 4 4 2 2 4 2 2 2 2 2 2 The aerials emit 125 kHz radio signals which are evaluated by the ID transmitter.
2. Outside door handle electronics The number of outside door handle electronic units depends on the model concerned (see table above). The 3 sensors in the outside door handle electronics send the following signals to the CAS control unit and the CA control unit: Unlock: When a hand reaches into the handle recess via capacitive sensor 1 Unlock: When a hand pulls on the outside door handle via tension sensor (redundant to capacitive sensor 1) Locking and deadlocking: On contact with the sensitive area of the door handle via capacitive sensor 2 A built-in aerial also sends radio signals in order to check for an ID transmitter located on the outside of the driver's door or front-passenger door. E70, E81, E87, E90, E91, E92, E93 The outside door handle electronics are installed in the outside door handle. E60, E61, E63, E64 The outside door handle electronics are behind the grip recess plate.
3. ID transmitter The ID transmitter evaluates the signals from the aerials. It also sends high-frequency radio signals to the FBD receiver. Inserting the ID transmitter into the slot deactivates all Comfort Access functions.
4. Remote control receiver for remote control services E64, E81, E87, E93 The remote control receiver is integrated in the interior mirror. E60, E61, E63, E70, E90, E91, E92 The remote control receiver is integrated into the aerial amplifier. The remote control (FBD) receiver picks up radio signals from the ID transmitter and forwards them to the CAS control unit. The Comfort Access control unit (CA control unit) activates the FBD receiver.
5. CAS control unit The CAS control unit (CAS: Car Access System) is the master control unit for all Comfort Access functions. The CAS control unit is the interface to the START/STOP button and to the slot for the ID transmitter. The electronic steering lock is also activated by the CAS control unit. The CAS control unit is connected with the following components via the K-bus (sub-bus): Outside door handle electronics (number depends on model concerned) Comfort Access control unit (CA control unit) Electronic steering lock When the vehicle is idle, communication may take place on the K-bus without waking up the vehicle.
6. START/STOP button The START/STOP button can be used to switch the terminals in sequence (0, R, 15, R, 0). The engine can be started by depressing the clutch or the brake (manual transmission/automatic transmission) and pressing the START-STOP button.
7. Slot for the ID transmitter/remote control On vehicles without Comfort Access: In order to start the engine, the remote control must be latched in place in the slot. On vehicles with Comfort Access: The remote control must be inserted into the slot if the battery in the ID transmitter is discharged. The engine can then be started up. Inserting the ID transmitter into the slot deactivates Comfort Access.
8. JBE: Junction box electronics E70, E81, E87, E90, E91, E92, E93 The junction box electronics activates the central locking system. If the CAS control unit approves the unlocking of the vehicle, for example, the doors will be unlocked.
9. KGM and KBM: Body gateway module and body basic module E60, E61, E63, E64 The body gateway module actuates the central locking in the front doors. The body basic module controls the central locking in the rear doors. If the CAS control unit approves the unlocking of the vehicle, for example, the doors will be unlocked.
10. Comfort Access control unit The Comfort Access control unit (CA control unit) actuates the internal and exterior aerials. An ID transmitter scan is carried out. At the same time, the FBD receiver is activated for any ID transmitters which may respond.

Comfort Access is used to implement the following functions

1. Passive Entry via driver's door or front passenger door
2. Passive Entry via tailgate
3. Passive Go
4. Passive Exit
5. Disabling an ID transmitter located inside the vehicle
6. Disabling an opposing command
7. Tamperproof lock

Passive Entry via doors

The vehicle is unlocked when the outside door handle is gripped or pulled. Condition: The ID transmitter must be located no further than 1.5 m from the aerial in the outside door handle.

Ideally, the user should carry the ID transmitter in a pocket.

First, the user is authenticated (= authenticity check).

The data transferred during the authenticity check is of course encrypted.

If the ID transmitter authenticity check is successful, the user will be granted access to the vehicle. The central locking is unlocked. The door can be opened.

The same principle is applied for the authenticity check for Passive Entry and Passive Go.

Authenticity check using the example of Passive Entry

1. Trigger signal at outside door handle electronics via capacitive sensor 1.
2. Request sent to outside door handle electronics to locate an ID transmitter via the aerials in the outside door handle. All ID transmitters associated with the vehicle and located outside of it are included in the search (low-frequency radio signal at 125 kHz). The search determines whether an ID transmitter associated with the vehicle is located in the operating range of the aerials in the outside door handle.
3. At the same time, the outside door handle electronics send a message to the CAS control unit via the sub bus (K-bus).
4. All ID transmitters located register with the CAS control unit by sending a radio signal via the FBD receiver (high-frequency radio signal, country-specific, e.g. 868 MHz).
5. The CAS control unit decides which of the registered ID transmitters will be used for the subsequent authenticity check.
6. This selection is sent to the outside door handle electronics in a message via the K-bus. At the same time, a request is sent to the outside door handle electronics to carry out a selective scan of the ID transmitter concerned.
7. All ID transmitters not picked up in this scan end reception readiness for the communication operation currently in progress.
8. The ID transmitter picked up via the selective scan responds by sending a radio signal to the CAS control unit via the FBD receiver (high-frequency radio signal at 868 MHz).
9. The CAS control unit evaluates the response signal and, if confirmation is valid, authorises Passive Entry. The vehicle is unlocked. In order that the vehicle can be opened quickly, the door lock is mechanically pretensioned with a spring. The spring ensures that the door unlocks whenever the user pulls the outside door handle to its full extent.
10. The tension sensor is set up with redundancy to the capacitive sensor (e.g. capacitive sensor 1 deactivated due to long-term lack of use). When the tension sensor detects the "Outside door handle pulled" signal, the door is unlocked. The door can be opened by pulling on the outside door handle again.

Passive Entry via the tailgate or front rear window

Comfort Access can be used to open the tailgate without actively using the ID transmitter. Condition: The ID transmitter must be located no further than 1.5 m from the aerial. Ideally, the user should carry the ID transmitter in a pocket.

To open the tailgate, it is necessary to press and hold the tailgate button for approximately 500 ms (top half of BMW logo on the E81, E87, grip on all other vehicles). If an ID transmitter is located in the vicinity of the luggage compartment, the tailgate will open.

If an ID transmitter is located inside the luggage compartment when the tailgate is closed (and there are no authorised ID sensors outside the vehicle), the tailgate will open up again.

The user's attention is drawn to the anti-theft alarm as follows

1. Visual signal via turn signal lights
2. Acoustic signal via siren, US version only

1. E61, E91: rear window

To open the rear window, the rear window button must be pressed for approx. 500 ms (under the rear window wiper arm).

If an ID transmitter is located in the vicinity of the rear of the vehicle, the rear window will open.

If an ID transmitter is located inside the luggage compartment when the rear window is closed (and there are no authorised ID sensors outside the vehicle), the rear window will open again.

The user's attention is drawn to this as follows: Visual signal via indicators and acoustic signal via sirens (on antitheft alarm system).

Passive Go

In order to switch the terminal and/or start up the engine, the ID transmitter must simply be located inside the vehicle (not necessarily in the slot).

On the following models, the luggage compartment counts as part of the interior: E61, E70, E81, E87, E91.

On all other models, it is not possible to start the engine if an ID transmitter is detected in the luggage compartment.

In principle, the authenticity check required is the same as that for Passive Entry (except that it is run via the interior aerials).

If there are no ID transmitters inside the vehicle when the START-STOP button is pressed: Check-Control message on instrument cluster.

Press the START/STOP button to switch the terminals. The terminal switching sequence is as follows: 0 -> terminal R -> terminal 15 -> terminal R -> 0.

The START/STOP button must be pressed for approximately 500 ms in order to start up the engine. The clutch pedal or brake pedal (manual transmission or automatic transmission respectively) must be depressed at the same time.

The engine may be started up in any terminal position.

Once the engine has been switched off, it may be restarted within 5 seconds even if no ID transmitter is detected inside the vehicle (i.e. no valid drive authorisation). This safety measure is required for possible emergencies.

Passive Exit

The sensitive area on the outside door handle must be touched (depends on model concerned) for the vehicle to be locked and then secured. Your hand must touch the middle of the sensitive area for at least 1 second.

If the locking area is touched for approx. 3 seconds, auto-remote closing will start. The side windows and sliding/tilting sunroof or Panorama glass sunroof on the E61/E91 then close. On the E64, the convertible top closes. If applicable, the exterior mirrors are folded in.

Auto-remote opening via the outside door handle is not possible.

Terminal R is deactivated when the outside door handle is locked.

Terminal 15 is not deactivated when the vehicle is locked. A Check-Control message appears as a warning when the driver's door is opened with terminal 15 ON.

Special feature: Comfort Access allows the vehicle to be locked whilst the engine is running.

1. E93

Note. No convenience closing of the hardtop via the exterior door handle electronics.

It is not possible to close the hardtop via the exterior door handle electronics. Convenience closing is performed at the lock cylinder.

Disabling an ID transmitter located inside the vehicle

When the vehicle is closed via the outside door handle, any ID transmitter inside the vehicle will be detected.

This ID transmitter is disabled for all Comfort Access functions. However, it is still possible to access the luggage compartment. The ID transmitter is reactivated when the vehicle is unlocked again.

Disabling an opposing command

When the vehicle is unlocked via the outside door handle, it cannot be locked again for approx. 2 seconds.

Similarly, when the vehicle is locked via the outside door handle, it cannot be unlocked again for approximately 2 seconds.

This allows the user to pull on the outside door handle to check that the vehicle is actually locked.

Tamperproof lock

The vehicle may only be locked and unlocked consecutively a maximum of 8 times. After this, the tamperproof lock is activated.

Operation is disabled for 10 seconds. The tamperproof lock is deactivated completely after 5 minutes. Once again, the vehicle may then only be locked and unlocked consecutively a maximum of 8 times.

The following details are available with regard to national versions

1. E93

Convenience functions performed using the remote control or ID transmitter depend on the national version concerned.

Conditions for operating Comfort Access (option 322) with the remote control or ID transmitter

COMFORT ACCESS CONDITIONS

Subject to change.

Scheme 1097

Park Distance Control (PDC) is an item of special equipment. Park Distance Control (i.e.: parking aid) assists the driver when he is parking and manoeuvring in tight spaces. This means that even small parking spaces can be used. At the same time, parking damage is reduced.

PDC uses ultrasonic sensors to measure the distance to objects within the effective range.

PDC is available in the following versions

1. Option 507: Park Distance Control (PDC), rear
2. Option 508: Park Distance Control (PDC), front and rear

The PDC button in the centre console switch cluster is only provided with option 508.

Compared to earlier systems, PDC has the following new features

1. Modified ultrasonic sensor with decoupling element on sensor housing
2. Increased range for ultrasonic sensor: 2.5 metres front and rear
3. Good detection of obstacles while remaining insensitive to echo pulses from the ground

The driver is warned of an object that could cause a collision as follows

1. Acoustic warning via (depends on equipment fitted): E70 Mid-range loudspeakers with Multimedia Platform (CHAMP), Multi-audio system controller (M-ASK) or Car Communication Computer (CCC) E87, E90, E91, E92, E93 2 acoustic generators (1 front, 1 rear) with radio without audio system Mid-range loudspeaker with BMW "Professional" radio, multi-audio system controller or Car Communication Computer R56 1 acoustic generators (rear) with Radio Wave Mid-range loudspeaker with Radio Wave CD, Radio Boost CD or Car Communication Computer
2. Visual warning by PDC image with multi-audio system controller and Car Communication Computer

The visual warning function in particular enables PDC to provide assistance for drivers who are hard of hearing or have restricted mobility.

The visual warning has additional benefits if the noise level inside the vehicle is very high (e.g. loud music).

PDC is not a substitute for the driver's personal judgement with respect to obstacles.

The ultrasonic sensors also have a "blind spot". In this blind spot, objects can no longer be detected.

The detection of objects can test the physical limits of ultrasonic measurements if the ultrasonic waves are reflected either poorly or not at all (e.g. due to trailer tow bars or narrow objects).

Objects close to the ground can suddenly "disappear", before a continuous tone sounds (e.g. a high kerbstone).

Loud noises outside and inside the vehicle can drown out the PDC signal tone.

It therefore remains the driver's responsibility to watch for obstacles, even in vehicles with PDC.

PDC consists of the following components

1. Ultrasonic sensors E70 8 ultrasonic sensors with option 508: Park Distance Control (PDC), front and rear E87, E90, E91, E92, E93 4 ultrasonic sensors with option 507: Park Distance Control (PDC), rear 8 ultrasonic sensors with option 508: Park Distance Control (PDC), front and rear R56 4 ultrasonic sensors with option 507: Park Distance Control (PDC), rear There are 4 ultrasonic sensors in each of the front and rear bumpers. The ultrasonic sensors emit ultrasonic pulses. These ultrasonic pulses are reflected by obstacles (echo pulses). The ultrasonic sensors receive and amplify these echo pulses. The amplified echo pulses are then converted into a digital signal. Each ultrasonic sensor has its own electronics, its own power supply and its own data connection to the PDC control unit.

The measuring range of the ultrasonic sensors is between approx. 25 centimetres and a maximum of approx. 250 centimetres. A continuous warning tone sounds when the distance is less than about 25 centimetres.

Dirty sensors, moisture, ice and snow can also cause the continuous warning tone to sound.

Note. Cleaning the ultrasonic sensors

To make sure the system remains fully operational, keep the ultrasonic sensors clean and free from ice. Do not clean by spraying high-pressure washers directly at the ultrasonic sensors. When cleaning, always maintain a minimum distance of at least 10 centimetres.

Note. Make sure the decoupling element on ultrasonic sensor is correctly located.

The respective decoupling element must be correctly located. Otherwise, transmission and reception will be impaired.

1. PDC button E70, E87, E90, E91, E92, E93 The PDC button is integrated in the centre console switch cluster (no control unit). The signal from the PDC button is read by the IHKA (or IHKR/IHR control unit) control unit. In turn, the IHKA control unit sends a signal on the K-CAN. The PDC button is used to manually switch the Park Distance Control system on and off. When the PDC is switched on, the function LED in the PDC button lights up. If a fault develops in the PDC, the function LED in the PDC button flashes.
2. PDC control unit The PDC control unit controls the ultrasonic sensors for transmitting ultrasonic pulses. The PDC control unit also receives the digital signals from the individual ultrasonic sensors. From the individual digital signals, the PDC control unit calculates the minimum distance between the ultrasonic sensor and the object. When an object is detected, an acoustic warning and a visual warning are given.

The PDC control unit is connected to various other control units via the bus system

1. RAD2, CHAMP, M-ASK or CCC: BMW "Professional" radio, Multimedia Platform, multi-audio system controller or Car Communication Computer E70, E87, E90, E91, E92, E93 Depending on the equipment fitted, the audio master emits acoustic PDC warnings via the mid-range loudspeaker.
2. Radio Wave CD, Radio Boost CD or CCC: Radio Wave CD, Radio Boost CD or Car Communication Computer R56 Depending on the equipment fitted, the audio master emits acoustic PDC warnings via the mid-range loudspeaker.
3. CID: Central Information Display E70, E87, E90, E91, E92, E93 The visual PDC warnings are given in the Central Information Display (CID). In addition, information regarding a Check-Control message that may be present is shown.
4. KOMBI: Instrument cluster E70, E87, E90, E91, E92, E93 A current Check-Control message is indicated by a symbol in the LCD display in the instrument cluster. Moreover, the instrument cluster also provides the exterior temperature and the kilometre reading for the PDC control unit. The PDC control unit is then able to correct the calculated distance with a factor corresponding to the outside temperature.
5. KOMBI and CID: Instrument cluster and Central Information Display R56 The instrument cluster has two section. The instrument cluster itself is in the middle of the dashboard. The auxiliary instrument is on the steering column. The KOMBI and the CID are both control units. These control units are plugged into one another an installed together in the dashboard. All equipment versions are connected to the auxiliary instrument via a K-bus. The auxiliary instrument is the gateway to the K-CAN. A current Check-Control message is indicated by a symbol in the LCD display in the auxiliary instrument. The instrument cluster provides the exterior temperature and the kilometre reading for the PDC control unit. The PDC control unit is then able to correct the calculated distance with a factor corresponding to the outside temperature.
6. EGS: Electronic transmission control On vehicles with automatic transmission, the electronic transmission control (ESG) supplies the signal that reverse gear is engaged. The PDC control unit activates PDC after a short delay (approx. 1 second). This prevents PDC from being unexpectedly activated on vehicles with automatic transmission, fro example when the selector lever is moved from "P" to "N" via "R".
7. DSC: Dynamic Stability Control The DSC control unit supplies the PDC with information about the road speed and distance travelled.
8. FRM: Footwell module On vehicles with manual transmission, the footwell module (FRM) supplies the signal that reverse gear is engaged.
9. CAS: Car access system The CAS control unit supplies the PDC with the terminal status (e.g. terminal 15).
10. AHM: Trailer module The trailer module (AHM) sends a signal indicating whether the vehicle is towing a trailer or if a rear carrier rack is fitted. If a trailer or rear carrier rack is recognised, the acoustic and visual warnings for the rear bumper are deactivated.

PDC incorporates the following functions

1. Acoustic warnings
2. Visual warning with multi-audio system controller and Car Communication Computer
3. Check Control
4. System limits

Acoustic warnings

The acoustic warnings are emitted by

1. E70 Mid-range loudspeaker with CHAMP, M-ASK or CCC If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated. The mid-range loudspeakers can be actuated. (depending on the model concerned, the mid-range loudspeakers in the left/right front doors or left/right rear doors are actuated, for example) If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.
2. E87, E90, E91, E92, E93 2 acoustic generators (1 front, 1 rear) with radio without audio system The PDC control unit directly actuates the acoustic generators (front/rear in vehicle interior). Within the acoustic generator, the control signal is transformed to approx. 48 volts. This voltage excites a piezoceramic element that together with the resonator (housing) generates a warning tone. Up to 09/2006, the tone is in the frequency range of approximately 1 kHz. From 09/2006 the tone is in the frequency range of approximately 1.5 kHz (front) or 1.0 kHz (rear). Mid-range loudspeaker with RAD 2, M-ASK or CCC If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated. The mid-range loudspeakers can be actuated. (e.g. the mid-range loudspeakers in the front doors, left/right, in the rear shelf, left/right, in the rear doors, left/right, in the rear shelf, left/right or in the rear side trim, left/right are actuated, depending on the vehicle model.) If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.
3. R56 1 acoustic generator (rear) with Radio Wave The PDC control unit directly actuates the acoustic generators (in rear of vehicle interior). Within the acoustic generator, the control signal is transformed to approx. 48 volts. This voltage excites a piezoceramic element that together with the resonator (housing) generates a warning tone. The tone is in the frequency range of approximately 1 kHz. Mid-range loudspeakers with Radio Wave CD, Radio Boost CD or CCC If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated. The midrange loudspeaker on the left/right can be actuated. If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.

The distance to the object determines the tone sequence for the acoustic warning (the smaller the distance, the faster the tone sequence).

A distance of less than approx. 25 centimetres is indicated by a continuous tone. The continuous tone is emitted alternately from the front and the rear.

If the vehicle moves away from the object, the warning tone will be cancelled when the distance increases by more than 10 centimetres.

Effective range for acoustic warnings

1. approx. 60 centimetres for the ultrasonic sensors at the two corners of the front bumper
2. approx. 70 centimetres for the two middle ultrasonic sensors in the front bumper
3. approx. 60 centimetres for the ultrasonic sensors at the two corners of the rear bumper
4. approx. 150 centimetres for the two middle ultrasonic sensors in the rear bumper

Optical warning with multimedia platform or multi audio system controller or Car Communication Computer

The visual PDC warnings are given in the Central Information Display (CID). This is subject to the PDC display in the CID being active.

The visual warnings are given earlier than the acoustic warnings.

The effective range is approx. 2.5 metres at the front and rear.

The graphic display is shown on the CID. The PDC control unit supplies the distance between the ultrasonic sensor and the object detected via the K-CAN.

The PDC display on the CID is an overhead view of the vehicle with the effective range of the ultrasonic sensors.

The distance to objects detected is shown in the colours of traffic lights

1. Distance between 200 (250) and 101 centimetres: green
2. Distance between 100 an 51 centimetres: yellow
3. Distance less than 50 centimetres: Red

The PDC display appears as soon as the PDC is switched on (manually or automatically). The PDC display overrides other displays in the CID. When the PDC is switched off again, the previous display automatically appears again in the Central Information Display.

Check Control

If a fault should develop in the PDC, the function LED in the PDC button will flash with a frequency of 2 Hz.

In this situation, PDC cannot be switched on.

At the same time, a Check-Control message is displayed in the following form

1. Symbol in the LCD display in the instrument cluster
2. The following text appears in the status line of the Central Information Display: "PDC failure!" In the menu "BMW Service", the following text can be called up in the submenu "Check-Control messages": "Park Distance Control No acoustic warning available for Park Distance Control PDC. Have the problem checked by BMW Service as soon as possible."

If a fault memory entry is recorded, the kilometre reading and the outside temperature are recorded along with the type of fault.

System limits

PDC is not a substitute for the driver's personal judgement with respect to obstacles.

The ultrasonic sensors also have a "blind spot". In this blind spot, objects can no longer be detected.

The detection of objects can test the physical limits of ultrasonic measurements if the ultrasonic waves are reflected either poorly or not at all (e.g. due to trailer tow bars or narrow objects).

Objects close to the ground can suddenly "disappear", before a continuous tone sounds (e.g. a high kerbstone).

Loud noises outside and inside the vehicle can drown out the PDC signal tone.

It therefore remains the driver's responsibility to watch for obstacles, even in vehicles with PDC.

During operation, the following system functions, which require explanation, can occur due to the limits of the functional range (for the driver)

1. Under the following conditions, it could happen that the PDC gives a warning, even though there is no obstacle within the effective range: Ultrasonic sensor incorrectly located in its bracket Heavy rainfall Ultrasonic sensors covered in snow Exhaust gases Echo pulses caused by ground, e.g. extremely coarse road surface or high grass Very smooth walls in large, enclosed, rectangular spaces, e.g. in underground car parks (interference from previously reflected echo pulses) Protective cap for trailer coupling ball head incorrectly seated or objects being transported protruding into the effective range of the ultrasonic sensors.
2. Under the following conditions, the PDC may not recognise an obstacle that is present: Objects close to the ground (no reflection) Objects with corners and sharp edges (no reflection) If you drive alongside a wall for more than 3 seconds, the acoustic warning will be deactivated. Here, the distance must be greater than the effective range for the continuous tone (approx. 25 centimetres). As soon as the distance drops below 25 centimetres, the continuous tone will sound again. If the vehicle approaches an object too fast Starting up and moving away too quickly while PDC is starting

Conditions for switching on and off

PDC is switched on under the following conditions

1. PDC button pressed (PDC switched on manually), option 508 only
2. Reverse gear engaged (PDC switched on automatically)

PDC is switched off under the following conditions

1. Reverse gear disengaged, option 507 only
2. PDC button pressed (PDC switched off manually), option 508 only
3. Ignition switched off (PDC switched off automatically
4. After driving approx. 50 metres
5. After exceeding a speed of 30 km/h

When towing a trailer or driving with a rear carrier rack, the acoustic and visual warnings for the rear bumper are deactivated by the trailer module (AHM).

The trailer or rear carrier rack must be electrically connected.

The visual warning (PDC display) is switched on in the Central Information Display (CID) as follows

1. "Settings (i)" menu
2. "Vehicle settings" menu
3. "PDC" menu
4. Activate "Display on"

See also:
• SYSTEM FUNCTIONS
• DEADLOCKING