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

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

- except CODE (ZU7) National version for Canada


- except CODE (ZU8) National version for USA







A Transmitter key (A8/1) in position "A"
B Transmitter key in position "B"
C Transmitter key in position "C"
D Transmitter key in position "D"
A8/1 Transmitter key
N73 EIS [EZS] control unit







Networking of components
A8/1 Transmitter key
N3/20 CDI control unit, with engine 642
N3/21 CDI control unit, with engine 646
N3/23 ME-SFI control unit, with engine 272
N15/3 ETC [EGS] control unit
N26/5 ELV control unit
N73 EIS [EZS] control unit

Description
The drive authorization system stage 3 (DAS 3) is compound system of the following control units:
- EIS [EZS] control unit
- CDI control unit
- ME-SFI [ME] control unit
- ETC [EGS] control unit
- ELV control unit

The encrypted data is exchanged between the transmitter key and the EIS control unit via infrared signal The "Hash value" determined during the dialog between the transmitter key and EIS control unit is calculated according to the hash method.
The EIS control unit transmits the corresponding hash value from the transmitter key to the control units involved. Check and release is performed separately by each control unit.

Hash function
Each actuation of the transmitter key results in a new initial value for calculating the "hash value" for recognition of drive authorization. For safety reasons it is not possible to recalculate the initial value.

Function sequence
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.
Bi-directional infrared communication is accomplished between the transmitter key and the EIS control unit

The function keys of the transmitter key are not active as long as the EIS [EZS] control unit is inserted

Transmitter key in position "A"
- "Circuit 15C ON"
The inductive energy transfer for supplying the transmitter key with power is activated.

- The encrypted data is exchanged between the transmitter key and the EIS control unit for key identification. The "hash value" for the key identification procedure is calculated.
- The electric steering lock (ELV) is unlocked by the ELV control unit and secured. A feedback is output by the EIS [EZS] control unit. The transmit buttons on the transmitter key are disabled. The rotary lock is released and the controller area network bus, class B (interior compartment) CAN B) is woken up.
- On vehicles with code (FY1) Anti-theft alarm system with interior protection, tow-away protection or with code (FZ5) Anti- theft alarm (ATA) or with code (FZ4) ATA 2 with interior protection, tow-away protection and battery-operated horn. the ATA is deactivated and the interior central locking button (N72/1s7) is released.

When turned, the transmitter key is secured against being pulled out.

Transmitter key in position "B"
- "Circuit 15R ON" is activated.
- Statuses "Circuit 15C ON" and "Circuit 15R ON" are stored on the activated CAN B bus as message.
- The controller area network bus, class C (engine compartment) (CAN C) is woken up
- The load switch, circuit 15R, is closed.
- Data is exchanged between the CAN-B and CAN-C.

Transmitter key in position "C"
- "C. 15 ON" is activated.
- "C. 15 ON" and "C.. 15X ON" are stored as message on the activated CAN-B.
- The engine control is released.
- The electronic transmission control (EGS) is released.
- The load switch, circuit 15R remains closed.
- The load switch, circuit 15, is closed.

Transmitter key in position "D"
- "C.. 15X ON" is deactivated.
- The load switches, circuit 15R and circuit 15, remain closed.
- "C. 50 ON" is output to CAN-B and CAN-C.
- The relay starter c. 50 (K40/9k5) is actuated via the ME-SFI control unit or CDI control unit.
- Message "C. 15X ON" is transmitted to the CAN-B only when the status "C. 50 OFF" and "Idle stable" are present.

After releasing in position "D", the transmitter key automatically turns back to position "C ".

Shut off vehicle
If the transmitter key is turned back from position "C" to position "B" or from position "B" to "A" in the EIS [EZS] control unit, the status "Circuit 15R ON" or "Circuit 15 ON" changes on the CAN-B. The power is switched off by the load switches.

Function sequence when turned back to position "D"
- Engine is shut off, i.e. Status "Circuit 61 OFF" is activated.
- "C. 15 OFF".
- Statuses "Circuit 15C ON" and "Circuit 15R ON" are stored on the activated CAN B bus as message.
- Load switch c. 15 is opened.

Function sequence when turned back to position "D"
- "Circ. 15C ON".
- The load switch, circuit 15R, is opened.
- Communication with the CAN C is deactivated.
- The transmitter key can be removed from the EIS control unit.

On vehicles with code (G40) Automatic transmission the mechanical shift-lock function prevents that the transmitter key can be removed from position "A", if the selector lever is not in position "P". This caused by a mechanical function in the EIS [EZS] control unit.

When restarting, the EIS [EZS] control unit can request a new check for identifying the transmitter key even when the transmitter key has not been removed.

Function sequence when transmitter key is removed
- "Circuit 15C OFF"
- The electric steering lock is locked by the ELV control unit.