Drive authorization system level 3 (DAS [FBS] 3), function - GF80.57-P-0003SX

MODEL 221.0 /1, 216.3 up to Model Year 8

Fig 1: Drive Authorization System Level 3 (FBS 3) Function Diagram

Courtesy of MERCEDES-BENZ USA

Description

The drive authorization system stage 3 (DAS 3) is a system combination of control units consisting of:

EIS control unit (EZS),
ME-SFI control unit or CDI control unit
Fully integrated transmission control (VGS) control unit or electronic transmission control (EGS) control unit
Intelligent servo module for DIRECT SELECT

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 by using the "Hash" function, a number can easily be calculated from another number. It is not possible to calculate vice versa.

The encrypted data is exchanged between the transmitter key and the EIS control unit via infrared signal. The code is computed in dialog between the 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

Up to eight transmitter keys can be used simultaneously. A special memory cell is available for each transmitter key in all relevant components.

Function

The transmitter key identifies itself to the EIS control unit when inserted into the EIS control unit. If identified positively, the lift solenoid in the rotary lock is enabled in the EIS control unit. The transmitter key can now be turned.

The function keys in the transmitter key are no longer active. When turned, the transmitter key is secured against removal.

An encrypted request is sent to the drive authorization by the:

ME-SFI control unit or CDI control unit,
fully integrated transmission control (VGS) control unit or electronic transmission control (EGS) control unit, and
intelligent servo module for DIRECT SELECT

to the EIS control unit. Each of these control units checks separately whether the data package is enabled and provides the EIS control unit with a feedback. During this communication, the ME-SFI [ME] control unit serves primarily as a gateway between the chassis CAN and drive train CAN.

Transmitter key in position "0"

The inductive energy transmission to the voltage supply of the transmitter key is switched on.
Encrypted data exchange between transmitter key and EIS control unit for identification.
Calculation of next hash value in transmitter key
After the calculation is completed, the transmitter key signals that the "power supply is switched off.

After positive identification the following is performed:

Release of rotary lock in EIS control unit for transmitter key
Key position recognition switched on.
Wake-up of chassis CAN and interior CAN
Signal output of circuit 15C

Transmitter key in position "I"

Actuation of circuit 15R
Status output of circuit 15R from EIS control unit to chassis CAN and interior CAN

Transmitter key in position "II"

Circuit 15 is actuated
Status output of circuit 15 and circuit 15X from EIS control unit to chassis CAN and interior CAN

Transmitter key in position "III"

Actuation of starter (M1) by relay circuit 50, starter (N10/1kH) via ME-SFI control unit and CDI control unit
Output of status c. 50 to chassis CAN and interior CAN
Circuit 15X is actuated by chassis CAN and interior CAN until circuit 50 is off again and the engine is running (circuit 61)

The transmitter key automatically returns to position "II" when released.

Take vehicle out of operation

When the transmitter key is turned back to the left, the engine is switched off and the circuit status is changed correspondingly. If the transmitter key is in position "I", circuit 15R remains switched on. If the transmitter key is in position "0", the transmitter key can be removed.

Keylock, function

Conditions of operation

Vehicle at rest

Function

The EIS control unit transmits the request to automatically shift the transmission to the "Park position" when

the transmitter key is removed from the EIS control unit, or
when the driver or front passenger door is opened (only with code (889) Keyless Go)

to the servo module for DIRECT SELECT. It shifts the transmission to the "Park position".

Emergency function

If the communication is interrupted or the EIS control unit or the servo module for DIRECT SELECT is defective, the emergency path is actuated. The EIS control unit on-board power supply voltage is switched to the emergency path. A spring accumulator is actuated in the servo module for DIRECT SELECT and the transmission is moved to the "Park position". The electrical and mechanical system in the servo module for DIRECT SELECT are synchronized automatically after reproducing the functionality.

Drive authorization system, stage 3 (DAS 3), location of components		GF80.57-P-0003-01SX
Drive authorization system, stage 3 (DAS 3), block diagram		GF80.57-P-0003-02SX
Transmitter key, component description	A8/1	GF80.57-P-6010SX
Intelligent servo module (ISM) component description	A80 Model 221 with transmission 722.9	GF27.19-P-4015SX
Intelligent servo module (ISM) component description	Model 221 with transmission 722.6	GF27.19-P-4015SXA
CDI control unit component description	N3/9 Model 221.0/1 with engine 642	GF07.16-P-6000SX
ME-SFI [ME] control unit, component description	N3/10 Model 221 with engines 272.965 and 273.961	GF07.61-P-6000V
ME-SFI control unit, location/task/design/ function	N3/10 Model 221 with engine 275.953/982	GF07.61-P-5000M
ETC [EGS] control unit, component description	N15/3 Model 221 with transmission 722.6	GF27.19-P-4018G
Electronic ignition/starter switch control unit (EIS) component description	N73	GF80.57-P-6000SX
VGS control unit, component description	Y3/8n4 Model 221 with transmission 722.9	GF27.19-P-4016SX