The functional range of the SZL can be divided into three main blocks:
In the steering column switch centre, the following functions can be operated quickly and ergonomically by the driver:
The multifunction steering wheel (MFL) consists of
Located below the multifunction steering wheel (MFL) are
The electronic control for the steering column switch centre (SZL) is divided into two electronic modules:
The signal transfer from the control elements in the multifunction steering wheel (MFL) is ensured by a coil spring.
The gear selector lever is used for fully electronic selection of the gear positions R - N - D and P (reverse gear - neutral position - drive - park position).
The desired drive position is registered by seven Hall sensors. The Hall sensor are configured in such a way that if an individual Hall sensor fails the operability of the gear selector lever is retained.
The gear selector lever involves the following functions
Function |
Operation |
|---|---|
Drive position D (Drive) |
Overpress downwards |
Drive position R (reverse gear) |
Overpress upwards |
Drive position N (neutral position): |
from drive position P: one-touch upwards or downwards from drive position D: one-touch upwards from drive position R: one-touch downwards |
Position P (park position) |
Touch lever inwards |
Information displayed to the driver
Transfer concept: When the driver operates the steering-column lever or the axial one-touch button, a message is sent to the EGS (Electronic Gearbox Control) control unit.
Signal path: From SZL (steering column switch centre) -> data bus BYTEFLIGHT -> SIM (Safety Information Module) -> data bus BYTEFLIGHT -> ZGM (Central Gateway Module) -> data bus PT-CAN -> EGS (Electronic Gearbox Control).
For reasons of safety, there is also a serial line between the SZL and EGS. The same messages are transmitted across this line as across the buses.
Electronic parking lock: with electronic gearbox control, the steering column lock can be eliminated as an antitheft measure: the electronic parking lock replaces the steering column lock.
Electronic parking lock emergency unlock: in an emergency, the electronic parking lock be unlocked mechanically:
The steering-column lever for cruise control increases or reduces the travelling speed.
Function |
Operation |
Switch from cruise control OFF to cruise control ON and set the current speed. If the cruise control is already switched on, the set speed is increased/reduced. |
One-touch forwards/backwards |
Switch from cruise control OFF to cruise control ON and set the current speed. If the cruise control is already switched on, the next-highest / next-lowest stored speed stage is set. |
Overpress forwards/backwards |
Calls up stored speed |
Touch lever inwards |
Sets or deletes speed stage |
Touch lever inwards (long - at least 3 seconds) |
Switches off cruise control |
Touching lever up/down |
Programming required speed: It is best to program required speeds when the vehicle is stationary! Reason: when the vehicle is moving, the speed entered as required speed is set immediately!
Deleting required speed:
Transfer concept: When the driver operates the steering-column lever or the axial one-touch button, a message is sent to the DME/DDE.
Signal path: From SZL (steering column switch centre) -> data bus BYTEFLIGHT -> SIM (Safety Information Module) -> data bus BYTEFLIGHT -> ZGM (Central Gateway Module) -> data bus PT-CAN -> DME/DDE.
Pressing the LOW function key shifts from the current gear downwards by one gear, e.g. 4 => 3 etc. When the function is activated, ”L” lights up on the gear selection display. If the LOW function key is pressed again, the normal gearbox program is returned. The display ”L” is switched off.
The following control units are involved in the message transmission for the SZL:
For safety reasons, there are two serial cable connections in addition to the bus connection:
For all work on the steering column switch centre, comply with the safety legislation for work on airbags!
Disconnect battery!
In an emergency, the electronic parking lock be unlocked mechanically: Undo the cover in the footwell on the driver's side at the left-hand A-pillar.
In the USA, the cover can only be removed with the identifier. This ensures that unauthorised persons are unable to release the electronic parking lock manually.