GF80.57-P-0003R Drive Authorization System Level 3 (DAS (FBS) 3), Function

GF80.57-P-0003R Drive Authorization System Level 3 (DAS [FBS] 3), Function

Component Identification:

Description
The drive authorization system stage 3 (DAS 3) is a system combination of control units consisting of:
^ EIS control unit
^ ME control unit
^ Electric steering lock control unit (with transmission 716)
^ Electronic selector lever module control unit (with transmission 722)
^ Fully integrated transmission control (VGS) control unit (with transmission 722.9)

The encrypted data is exchanged between the transmitter key and the EIS control unit via infrared signal The code is computed in dialog between transmitter key and the EIS control unit using the Hash method.
The corresponding hash value of the transmitter key is transmitted to control units by the EIS control unit. Check, release and feedback is performed separately by each control unit.

Hash function
The encrypted base module of the drive authorization system, stage 3 (DAS 3) is a so-called hash function. The most important property of the hash function is the one-way characteristic. This means that another number can be calculated using the Hash function from an initial number, however that calculation of the initial number in the opposite order is practically impossible.

When inserted into the EIS control unit, the power supply to the transmitter key is established inductively via a coil in the EIS control unit so that the vehicle can be started even when the transmitter key battery is discharged.
The transmitter key cannot be removed in positions "B", "C" and "D".
The function keys of the transmitter key are not active as long as the EIS control unit is inserted
Up to 8 transmitter keys can be used simultaneously. The EIS control unit controls the transmitter key.

Transmitter key in position "A"
^ Inductive energy supply to power supply for transmitter key switched on
^ Encrypted data exchange between transmitter key and EIS control unit for identification.

The next Hash values are computed in the EIS control unit. After completion of the calculation, the energy transmission is switched off. After positive identification the following is performed:
^ Release of lift solenoid for rotary lock in EIS control unit for transmitter key.
^ Switch on transmitter key position recognition
^ Wake-up of CAN-B
^ Output of circuit 15C
^ Encrypted data exchange between transmitter key and steering lock control unit for identification Following successful communication, the steering lock is unlocked by the electric steering lock control unit (with transmission 716)

Transmitter key in position "B"
^ Actuation of circuit 15R.
^ Output of status for circuit 15R on CAN-B

Transmitter key in position "C"
^ Circuit 15 is actuated.
^ Output of status circuit 15 to CAN-B and CAN-C as well as circuit 15X to CAN-B.
^ Encrypted request for ME-SFI control unit
^ Encrypted request for VGS control unit
^ Encrypted request for electronic selector lever module control unit
^ Output of data transmitted by CAN-C to CAN-B
^ Output of data transmitted by CAN-B to CAN-C

Transmitter key in position "D"
^ Actuation of starter via ME-SFI control unit M1
^ Output of status for circuit 50 to CAN-B and CAN-C.
^ Circuit 15X is removed from CAN-B until circuit 50 is off again and the engine is running (circuit 61)

The transmitter key automatically returns to position "C" when released

Take vehicle out of operation
Take vehicle out of operation Turning transmitter key back to left switches off the engine. The following functions are realized in the EIS control unit:

Transmitter key in position "B"
^ Switch off signals circuit 15 and 15X
^ Adjust CAN C communication

Transmitter key in position "A"
^ Switch off signal circuit 15R
^ Steering lock is locked by steering lock control unit
^ Transmitter key can be removed (with transmission 722, the selector lever should be in position P)

The EIS control unit can request a new check for identification of the transmitter key during restart without removing the key.

Memory block number and key dependency (up to 31.5.05)
One memory block number each is assigned to key rails 1, 2 and 3. The third memory block number is used when the key assignment is switched off and for key rails 3 to 8. The memory block number is required for key-dependent storage (e.g. adjusting the air conditioning or the instrument cluster).

Output of memory block number to CAN-B (up to 31.5.05)
Output of the memory block number is performed by the EIS control unit by:
^ Open central locking (CL) with transmitter key.
^ Insert or remove transmitter keys from EIS control unit.