The entire central body electronics system consists of the following components:
As of 9/95, the peripheral module, driver's door is integrated into the peripheral module switch block.
The following functions are possible with these modules:
All wipe/wash functions can be switched on with the wiper switch as of terminal R (ignition lock in position 1).
The wiper switch can be switched to intermittent wipe, stage 1 and stage 2. These settings are coded by means of two lines leading to the general module. They are each switched to ground
On vehicles equipped with the special option automatic interval control (AIC) (as of March 1996), in the "intermittent" switch position, the intermittent wipe function is controlled by a rain sensor (refer to functional description for automatic interval control).
A knurled wheel with a potentiometer is integrated in the wiper switch. This makes it possible to set four different intervals. These times are also controlled according to road speed. The faster the vehicle is driven, the shorter the interval.
On vehicles equipped with automatic interval control (AIC) (as of March 1996), the sensitivity of the rain sensor can be be influenced with the thumbwheel.
The wiper motor is configured for two different wiper speeds. The load is switched via two external relays.
The end position (park position) of the wiper motor is recognized by means of a reset contact integrated in the motor. This contact switches ground to the general module when the motor has reached its end position.
The reset contact is also used for monitoring the wiper motor. If the contact signal is not received for 16 seconds with the wiper motor switched on (e.g. dry running), the wiper motor is switched off in order to protect it from overloading.
The wiper is not switched on again before it has been switched off and a lock-out time of 3 minutes has elapsed.
The wiper speed is set at the wiper switch. If automatic interval control is not installed, the wiper speed will be additionally controlled according to the road speed. The following settings apply:
Road speed |
Switch set to stage 1 |
Switch set to stage 2 |
|---|---|---|
< 6 km/h |
Intermittent wipe |
Wiper motor at stage 1 |
> 6 km/h |
Wiper motor at stage 1 |
Wiper motor at stage 2 |
When stage 2 is switched on, stage 1 cuts in at > 210 km/h to prevent the wiper arm from lifting.
On vehicles with the optional extra automatic interval control (AIC) (as of March 1996), the windscreen wipers are not controlled according to road speed.
Since it is not possible to fold out the wiper arms in park position (e.g. to replace the wiper blades), the wiper arm can be positioned automatically in a fold-out position as required.
Proceed as follows for this purpose:
On series E39 vehicles, or vehicles equipped with optional extra automatic interval control (AIC) (as of March 1996), this fold-out function is not available.
The windscreen intensive wash function is switched on with the wiper switch and takes place automatically.
Initially, a pump sprays wash fluid on to the windscreen. The windscreen wipers are switched on after a time delay. The wash pump is then switched on and the intensive wash fluid rinsed off. The wipers are switched on again for a short time in order to wipe the windscreen dry.
The intensive wash pump is driven by means of an external dual relay module which also switches the pump for the headlight wash function.
The headlight wash function is triggered every fifth time wash or intensive wash is activated when the headlight or parking lights are switched on. The headlights are sprayed twice.
The headlight wash function is blocked for 3 minutes at the end of a wash cycle.
Switching off terminal R resets the repeat lock-out and the counter for wash operations. When terminal R is switched on again with the lights on, the headlight wash function can be activated immediately.
The headlight wash pump is driven by means of an external dual relay module which also switches the pump for the intensive wash function.
The contact pressure of the windscreen wiper on the driver's side is set in five stages depending on the vehicle speed and the set wiper function. The following settings apply:
Road speed |
Wiper switched off |
Wiper switched on |
|---|---|---|
< 6 km/h |
Stage 0 if a higher stage was not previously active, otherwise stage 1. |
Stage 0 if a higher stage was not previously active, otherwise stage 1. |
6 - 100 km/h |
Stage 1 |
Stage 1 |
100 - 140 km/h |
Stage 1 |
Stage 2 |
140 - 180 km/h |
Stage 2 |
Stage 3 |
> 180 km/h |
Stage 3 |
Stage 4 |
The contact pressure is increased by one stage at a time when "wash" is activated.
The adjustment unit for windscreen wiper pressure control is positioned by means of a cam switch in the drive. This switch switches ground to the general module when a position (= stage) is reached.
To prevent blocking, the ADV motor is protected by the general module by means of a time-dependent cut-out facility. If the signal from the cam switch is not received due to a fault, the ADV motor is switched off after a certain time.
This cut-out function is cancelled by switching off terminal R.
The interior lighting is controlled by following switches and systems:
The lights of the interior lighting system can be switched on and off by means of the button at the front of the central light unit. However, the lighting is still controlled automatically by the general module.
This means the interior lighting switched off by means of this button would be switched on again by opening a door.
As a special function, the interior lighting can be switched off permanently when the button is depressed for longer than 3 seconds. The system reverts to automatic mode when the button is pressed once again.
The following lights in the vehicle can be switched on when the vehicle is parked:
The voltage (B+ supply) for these loads is supplied by the general module.
To ensure the vehicle battery is not discharged when the lights are switched on permanently, the general module switches off the B+ supply 16 minutes after switching off terminal R.
The "load cut-out" line is also routed to the closed-circuit (standby) current relay K72. This relay switches the load circuits for:
Relay K72 therefore disconnects these systems from the terminal 30 supply 16 minutes after switching off terminal R.
These loads are switched on again when terminal R or 15 is switched on in conjunction with a signal change at an input of the general module or peripheral module, e.g. opening a door, opening the front (bonnet) lid, unlocking a door.
The central locking system can be operated via following operating points:
The vehicle can be locked and unlocked centrally by means of the ZV button in the vehicle (centre lock button).
A locked door can be unlocked and opened from the inside by pulling the door handle twice.
To avoid unintentional locking (lock-out) the ZV button is inoperable when:
A locked vehicle (arming after ignition OFF, opening/closing driver's door and locking via door lock or remote control) cannot be opened with the ZV button.
Two microswitches (= lock contacts) are switched by the lock cylinders in the front doors. These two contacts switch B+ to the door module of the corresponding door and signal "lock/arrest" and "unlock".
There is no lock cylinder in the passenger's door if remote control is installed.
Note: On series E38 up to 9/95 the "driver's door module" and the "switch block for mirror and power window operation" are two separate control units. As of 9/95, the door module, driver's door is integrated in the switch block.
Two microswitches (= lock contacts) are switched by the lock cylinder in the rear lid. These two contacts switch B+ to the general module and signal "lock/arrest" and "unlock".
If the vehicle key is turned through 90o beyond the "lock/arrest" position and removed (slot of cylinder lock horizontal) the rear (boot) lid remains locked even when the central locking system is unlocked from a different operating point ("hotel or workshop setting").
Note: There is no cylinder lock in the boot lid on the series E39 touring.
A differentiation must be made between two central locking statuses on all vehicle doors:
When locking, the locking button is pulled downward. The door can no longer be opened from the outside with the door handle. The door can be opened from the inside by pulling the door handle twice.
The driver's door remains unlocked if the vehicle is locked with the driver's door open.
A locked vehicle can be unlocked from the inside by means of the ZV button.
When arresting, the rotary latch lock is uncoupled internally from the opening mechanism. The door can be opened neither from the outside nor from the inside. The ZV button is inoperable.
The vehicle is locked and arrested automatically by operating the central locking system via the lock cylinders or by remote control when the ignition lock is in position 0 (terminal R and 15 switched off) and the driver's door was opened and closed at least once after switching off terminal R.
The front central locking drives are driven by means of transistors in the relevant door modules. The rear door drives and fuel filler flap are driven by means of a relay in the general module.
The central locking drive consists of an electric motor and an integrated microswitch (= position switch). The rotary movement is transmitted by means of a gear system to the mechanics of the rotary latch.
After activation of the central locking system, the electric motor is switched on until the position switch in the drive reaches the "locked" position. If the doors are to be arrested, the electric motor is activated once again and the gear mechanism is moved beyond the "locked" position into the "arrest" end position.
Overloading due too frequent operation must be avoided since the electric motors in the central locking drives are blocked in the end position (in arrest position). For this reason, the central locking system is blocked by a lock-out function if operated 32 times within 2 minutes such that a function is carried out only every 4 seconds.
The repeat lock-out is cancelled after 3 minutes.
For reasons of safety, the central locking is unlocked if the basic module recognizes an accident (crash). The impact is recognized:
In addition to unlocking the doors, the hazard warning lights and the interior lighting are switched on.
Crash recognition is switched off when the ignition lock is in position 0 or the central locking in the "arrested" position.
The door mechanism is uncoupled from the ZV drive when an electrically locked door is unlocked mechanically by means of the inner door handle (door handle pulled twice). The lock mechanism and ZV drive assume an opposing status, i.e. they are asynchronous.
The general module recognizes this asynchronous status by means of the door contact signal which indicates that the door is open.
The next time the central locking system is locked electrically, the door is re-synchronised automatically, in that, after being locked, the system unlocks and then locks again.
In various country versions (e.g. USA), "selective unlocking" is coded in the general module. In this setting, initially, only the driver's door is unlocked when unlocking for the first time via the lock contact or remote control. The remaining doors are set from the position "arrested" to "locked" so that they can only be opened by means of the inner door handle.
All doors are unlocked when the vehicle is unlocked a second time.
The automatic soft close function makes it possible to open and close the boot lid by means of an electric drive.
The boot lid can only be opened when the vehicle is unlocked. In addition, the boot lid lock must not be in the workshop/hotel position (= locking cylinder horizontal). "Open" boot lid is triggered by:
The rear (boot) lid is closed by lightly pressing the lid. The rotary latch of the rear (boot) lid is turned to its initial position. The rear lid contact signals to the general module that the rear lid is closed. An electric motor connected to the lock striker of the rear lid is activated by means of a relay in the general module. The electric motor turns the lock striker downward thus pulling the rear lid closed.
The electrical closing function is also active when the vehicle is locked.
The drive for automatic soft-close is an electric motor which turns the lock striker of the rear lid. The drive is activated by means of a relay in the general module. The direction of rotation of the motor is the same for opening and closing.
A microswitch is initially integrated in the drive in order to detect the position of the motor and thus of the lock striker and to signal this to the general module. The switch switches ground to the general module when the motor has reached the "lock striker in bottom dead centre".
To enable emergency operation in the case of power failure to the automatic soft-lock system, a linkage connection is provided between the lock cylinder and the rotary latch of the rear lid. This linkage mechanically unlocks and opens the rotary latch by turning the key as far as it will go (approx. 90o ) in anticlockwise direction.
The boot lid release facility makes it possible to release and open the boot (rear) lid electrically. The lid is released via a special drive with integrated restoring spring.
The drive is activated by means of a relay in the general module.
The boot lid can only be released when the vehicle is unlocked. In addition, the boot lid lock must not be in the workshop/hotel position (= locking cylinder horizontal). "Release" boot lid is triggered by:
The E39 touring boot lid is electrically opened by electrically turning the rotary latch and by turning the lock striker towards open.
To release the rotary latch, a special drive with integrated restore spring is installed in the boot lid.
The release drive is activated by the basic module via an external relay.
The lock striker is turned by an electric motor. The drive is activated by means of a relay in the general module. The direction of rotation of the motor is the same for opening and closing.
A microswitch is initially integrated in the drive in order to detect the position of the motor and thus of the lock striker and to signal this to the general module. The switch switches ground to the general module when the motor has reached the "lock striker in bottom dead centre".
The boot lid can only be unlocked and opened when the vehicle is unlocked. This is triggered by:
The rear (boot) lid is closed by lightly pressing the lid. The rotary latch of the rear (boot) lid is mechanically turned to its initial position. The rear lid contact signals to the general module that the rear lid is closed. The electric motor connected to the lock striker is activated. The electric motor turns the lock striker thus pulling the rear lid closed.
The electrical closing function is also active when the vehicle is locked.
In the event of the electrical system failing, the rear lid can be mechanically released and opened from the inside using the mechanical emergency release via a bowden cable.
Besides the boot lid, the rear window is also released by an electric drive drive when the release button is pressed.
The release drive is activated by the basic module via an external relay.
The rear window release button is installed in the rear window wiper arm.
The rear window can only be released when the vehicle is unlocked.
The power windows are operated by means of the "switch block for mirror and power window operation" in the driver's door and three further switches in each of the doors.
The switches in the passenger's door and in the rear doors signal the switch status via two lines to the door or general module (ground signal). The switch block in the driver's door transfers its data via the "P-bus" to the door and general module.
Note: On series E38 up to 9/95 the "driver's door module" and the "switch block for mirror and power window operation" are two separate control units. As of 9/95, the door module, driver's door is integrated in the switch block.
All switches feature two switch stages. The window is opened or closed by lightly pressing forward or back. On releasing the switch the power window drive is switched off immediately.
The second switch stage is activated by suppressing the first stage. The power window drive is now in automatic mode and is operated until the window is completely opened or closed. Automatic mode is cancelled by operating the switch once again.
Due to legal stipulations, automatic mode is dependent on coded data. Example: In the Australia variant automatic mode in "close" direction is only possible on the driver's door.
In automatic mode, the drive is switched off by way of current measurement. On reaching the end position, the drive is blocked temporarily thus resulting in an increase in the power intake. This increase in power intake is detected in the door module (front windows) or in the rear module (rear windows) and the drive is switched off.
A finger-trap protection strip is installed at the top of all door window frames. This strip consists of two contact strips enclosed in plastic which make an electrically conductive connection when pressure is applied.
If pressure is applied to the finger-trap protection strip while closing the window, the closing function is interrupted and the window is driven in open direction for approx. 1-2 seconds.
When pressure is applied permanently to the finger-trap protection strip, the window can only be closed by pressing the switch to automatic setting.
The finger-trap protection strips are monitored for line failure by means of a resistor connected in parallel. If a break occurs, the window can also only be closed by pressing the switch to automatic position.
The windows and sunroof can be opened and closed via the lock cylinder in the driver's door and by means of remote control.
Convenient opening takes place when the lock cylinder is held in the "unlock" position for longer than 3 seconds or when the corresponding button on the remote control is pressed and held.
Convenient closing takes place when the lock cylinder is held in the "lock" position for longer than 2 seconds or when the corresponding button on the remote control is pressed and held.
The functions can be activated or deactivated by encoding.
The power windows are active when terminal R is switched on. Initially, the power windows are still operable after switching off terminal R. Automatic cut-out (deactivation) takes place after 16 minutes.
Depending on legal stipulations in the relevant country, the power windows are additionally deactivated by opening the driver's or passenger's door.
Two different versions are codeable:
ECE version |
Deactivation after switching off terminal R and opening and closing the driver's or passenger's door. |
USA and Australia |
Deactivation after switching off terminal R and opening the driver's or passenger's door. |
These cutout (deactivation) conditions also apply to the sunroof.
The sunroof is controlled by a separate peripheral module (SHD module). This module also contains the load circuits for sunroof motor. It is connected directly to the sunroof motor.
The sunroof module is connected via the P-bus to the general module.
The switch for the sunroof has five different switch positions.
The five positions are transferred via three lines to the sunroof (SHD) module (ground signal).
Automatic mode which opens or closes the sunroof completely is triggered by pressing and holding the switch in "slide OPEN" and "close" position.
Two position transmitters (incremental transmitters) register the number of motor revolutions and derives the sunroof position from it.
The motor torque of the sunroof (SHD) drive is constantly calculated from the position transmitter pulses and the power intake of the motor. If the motor torque increases beyond a certain value, this is interpreted as jamming.
The finger-trap protection facility is active in the "close" direction both during normal closing (switch not pressed and held) as well as in automatic mode and during convenient closing of the sunroof. By pressing and holding the sunroof switch in the close direction, the finger-trap protection facility is deactivated in the case of fault.
If jamming is detected, the closing operation is terminated and the sunroof is opened briefly.
Important!
Finger-trap protection is no longer active when the sunroof is opened less than 4 mm.
The position value stored in the module is erased after disconnecting and reconnecting the battery or after switching the sunroof module off and on. The sunroof can only be operated in close or tilt directions.
To enable initialisation, set the sunroof in the "tilt" end position. On reaching this position, press and hold the switch in "tilt" for at least 15 seconds. The sunroof is now initialised.
In the same way as the power windows, the sunroof can also be opened or closed together with locking or unlocking the vehicle.
Convenient opening takes place when the lock cylinder is held in the "unlock" position for longer than 3 seconds or when the corresponding button on the remote control is pressed and held.
Convenient closing takes place when the lock cylinder is held in the "lock" position for longer than 2 seconds or when the corresponding button on the remote control is pressed and held.
The functions can be activated or deactivated by encoding.
The sunroof is active when terminal R is switched on. Initially, the sunroof is operable after switching off terminal R. Automatic cut-out (deactivation) takes place after 16 minutes.
Depending on legal stipulations in the relevant country, the sunroof is additionally deactivated by opening the driver's or passenger's door.
Two different versions are codeable:
ECE version |
Deactivation after switching off terminal R and opening and closing the driver's or passenger's door. |
USA and Australia |
Deactivation after switching off terminal R and opening the driver's or passenger's door. |
These cutout (deactivation) conditions also apply to the power windows.
The antitheft alarm system (DWA) monitors the doors and lids as well as the ignition lock, the vehicle tilt and the vehicle interior.
An acoustic and visual alarm is triggered in the event of alarm.
The DWA is controlled by the general module.
The antitheft alarm system is activated automatically when the vehicle is arrested. (Arrest = Switch off ignition, open and close driver's door, lock vehicle via lock cylinder or remote control.)
The coding data determines whether the DWA is armed and disarmed via the remote control only or by means of remote control and the lock cylinder.
If the antitheft alarm system (DWA) is only to be operated by way of remote control, an alarm is triggered when the vehicle is unlocked via the door lock.
The inputs are monitored after arming and a waiting period of approx. 3 seconds. This waiting time makes it possible, for example, to close a door shortly after arming the antitheft alarm system (DWA).
The status LED flashes for 10 seconds if one or several input signals are not in rest setting (e.g. door open) after arming. A switch which is not in rest position is not included in the monitoring function.
If the DWA is again armed within 10 seconds of being armed, the tilt sensor and the remote interior protection (remote interior protection as of 9/95) in the basic module are masked (special mode for inclined garages or motorail trains).
The "DWA armed or disarmed" status is stored in the general module independent of the power supply. Disconnecting and reconnecting the battery does not result in the system being disarmed.
An LED which serves as a visual indicator signals the DWA status.
DWA LED |
DWA status |
|---|---|
OFF |
Disarmed |
Permanent rapid flashing |
Armed |
Flashes for 10 seconds followed by permanent rapid flashing |
Input not in rest status |
Lights for 1 second followed by permanent rapid flashing |
Subsequent arming (= Tilt sensor and remote interior protection are deactivated) |
Flashes for 5 minutes followed by permanent rapid flashing |
Alarm triggering |
10 minutes steady light, then OFF |
Emergency disarming |
Flashes for 10 seconds then OFF |
Disarming after alarm |
Additional signalling during arming and disarming can be encoded (country-specific)
DWA status |
Hazard warning lights acknowledgment |
Horn acknowledgment |
|---|---|---|
Arming |
Warning flash once |
1 short tone signal |
Disarming |
Warning flash twice |
2 short tone signals |
As of 9/95, a radio remote interior protection system (FIS) is installed instead of the window monitoring with glass breakage recognition.
The radio remote interior protection monitors the vehicle interior using ultrasonic radio waves. A body moving in the vehicle changes the reflection of the radio waves. The radio remote interior protection facility triggers an alarm.
The radio remote interior protect module is installed in the roof headlining. The housing features ribs which direct the radio waves in a certain direction. This ensures that the sensing range of the radio waves is limited to the vehicle interior. For this reason, the installation direction of the module is predefined.
Different versions of the radio remote interior protection module are adapted for the different vehicle models. The different versions can be identified by means of the labelling on the housing and part number.
On series E39 touring models two radio remote interior protection modules are installed. The front module monitors the passenger compartment, the rear the luggage compartment. Both modules are installed under the roof headlining.
The radio remote interior protection module contains the complete electronics for the system. Radio remote monitoring is activated and deactivated via a line from the general module (connector X253 Pin 20) (the same line also activates and deactivates the tilt sensor and emergency current siren). The module for radio remote interior protection gives feedback to the basic module via a second wire (connector X253 5 or 6-pin on the rear FIS module in the E39 touring) as to whether the system is correctly activated. An alarm is also signalled via this line. The module is additionally connected to terminal 30 and terminal 31.
After arming the antitheft alarm system, radio remote interior protection is activated by the general module after a delay of 30 seconds. The radio remote interior protection system is not activated or deactivated under following conditions:
The radio remote interior protection is again activated after a delay of 30 seconds, if the conditions for switching off are no longer present.
To eliminate the risk of the system triggering incorrectly due to the radio remote interior protection under certain conditions (e.g. motorail trains of ship transport), the radio remote interior protection can be masked in the basic module when the DWA is armed. This is done by arming the DWA a second time within the space of 10 seconds (lock the vehicle twice via the lock cylinder or the radio key). The tilt sensor is also deactivated. The status LED indicates that deactivation has taken place by lighting briefly.
If the boot lid or rear window (E39 touring) are opened with the antitheft system armed, the boot lid/rear window contact, radio interior protection system and the tilt sensor are blanked out in the control unit. In this case, a signal exchange does not result in the alarm being triggered.
The blanked out signals are reactivated 30 seconds after closing the boot lid or rear window.
The alarm is triggered by the general module. The following acoustic signal generators are used:
The acoustic signal generator is driven for 30 seconds in the case of alarm. The alarm is interrupted immediately when the antitheft alarm system (DWA) is disarmed.
The signal generator can be coded to permanent tone or intermittent tone country-specific.
At the same time as the acoustic signal, and optical alarm is also triggered for about 5 minutes. The lights are switched on via the light module. The general module informs the light module via the K-bus and I-bus what lights are to be switched on.
The lights which are to be activated as part of the visual alarm are coded country-specific in the general module.
As of 9/95 an emergency siren is installed instead of the alarm horn.
In contrast to the alarm horn, electronic circuitry and a rechargeable battery are integrated in the emergency current siren. The emergency current siren can therefore be activated independent of the vehicle power supply system.
The emergency current siren is primed and deactivated via a line (connector X253 Pin 20) (the same line also activates and deactivates the tilt sensor and remote interior protection facility). The general module informs the emergency current siren via another line that an alarm has been triggered (same line as for horn, connector X254, Pin 17). With the emergency current siren primed, an alarm can still be triggered when the siren is disconnected from the vehicle electrical system or the vehicle battery is disconnected.
A differentiation is made between two basic versions of the emergency current siren for US and ECE operation. The ECE version can be used for both permanent tone as well as for intermittent tone operation. The mode of operation is coded automatically by means of the general module. When an alarm is triggered, the general module informs the emergency current siren of the coded mode of operation. This is stored in the siren so that the specified mode of operation is maintained even in the event of the siren triggering of its own accord. When the general module is recoded, the mode stored in the siren is also changed the next time the alarm is triggered.
It may be possible that the antitheft alarm system (DWA) can no longer be disarmed in the event of the remote control or central locking systems failing. In this case, the DWA must be disarmed, however, this procedure triggers an alarm.
Procedure:
The emergency disarming procedure is terminated if a door is opened or the ignition lock position changed during this waiting period.
Emergency disarming is restarted when, after closing the door, the ignition lock is switched from "0" to "1".
On vehicles without EWS (electronic immobilizer), the immobilization and starter interlock functions are carried out by the general module when the vehicle is arrested.
The immobilization function is provided by a line from the general module to the DME control unit. The DME is partly deactivated when the vehicle is arrested.
A second line leads from the general module to a starter interlock relay. This relay switches terminal 50 from the ignition lock to the starter. The engine can only be started when the vehicle is released and disarmed and terminal 15 is switched on.
As of 1/95, the EWS system undertakes these functions.
The mirrors are adjusted electrically by means of the peripheral modules for the driver's and passenger's doors. The adjustment switch is located in the central switch block on the driver's door.
Switch operation is transferred via the P-bus from the switch block to the peripheral module in the door. The door module drives the adjustment motors in the mirrors by means of semiconductor bridges.
Electric motors are installed in the mirror housing for horizontal and vertical adjustment.
If the vehicle is equipped with a seat/steering column memory the mirror positions are registered and stored accordingly.
The seat/steering column memory features its own peripheral module (its own diagnosis program) which is linked via the P-bus to the general module of the ZKE. The positions for the seat and steering column are registered and stored in this peripheral module.
Parallel to this, the mirror positions are stored in the peripheral modules of the doors (door modules).
The mirror positions are detected by means of potentiometers which are installed on the mirror drive.
Memory mode is operated by means of the memory switch which is linked by four lines to the peripheral module for the driver's door. Button operation is transferred via the P-bus to the general module.
The mirror, seat and steering column positions are stored as of terminal R. After pressing, the red memory button lights for max. 7 seconds. If one of the memory buttons (1, 2 or 3) is pressed during this time, the current positions are stored in the selected memory slot.
A stored position can be called up at any time. The function is, however, deactivated 16 minutes after switching off the ignition until terminal R is switched on again or until a signal change takes place at a module input (e.g. opening a door).
The positions are called up by pressing the required memory button (1, 2 or 3) until all adjustment have been carried out. In addition, it is possible to start an automatic operating sequence by briefly striking the button. This "single-strike mode" is possible when:
Mirror heating is controlled by the peripheral modules in the doors. The heating function is active as of terminal 15 (ignition lock position 2). The activation time is dependent on the outside temperature.
The general module receives the outside temperature from the IKE via the K-bus and determines a cycle time for heating operation. This time is transferred to the peripheral modules where it is carried out. Heating is no longer active at an outside temperature greater than 25 o C and it is switched on permanently at a temperature lower than -10 o C.
The electric motor drive is used to fold in the outside mirrors (special option) in the opposite direction of driving.
The button to fold in the mirrors is located in the switch block on the driver's door. The button signal is routed via the P-bus to the peripheral modules in the doors. Depending on the position of the mirrors, they are then folded in or out accordingly.
If a mirror is mechanically folded in, either by hand or due to an impact, it is mechanically uncoupled from the fold-in drive. A microswitch is installed in the mirror which recognizes this uncoupling and switches a ground signal to the appropriate peripheral module.
If a mirror which has been mechanically uncoupled is activated by the button being pressed, the fold-in motor will move the mirror in the fold-in direction until the microswitch registers the mirror being engaged. The maximum activation time of the motor is 15 seconds.
Since the mirror fold-in motors block when operated, thermal overloading is possible if operated frequently. In order to avoid overloading, a repeat lockout is provided which blocks the fold-in motors for 3 minutes after 6 operating attempts within 1 minute.
The Servotronic is a speed-dependant power steering control system.
The Servotronic is integrated in the general module. The speedometer A-signal (line) from the IKE is connected to the general module in order to evaluate the vehicle speed. In order to detect errors, in addition to the speedometer A-signal, the speed value is also transferred from the IKE via the K-bus to the general module.
The current for the electrohydraulic converter is controlled in the general module dependent on the driving speed. The higher the speed, the lower the converter current.