Stage 2 drive authorization system, function

S80.35-1772-06

Engine 601

Interlinkage of components (connection, radio remote control shut-off valve/DSV engine control module via CAN

CAN Controller Area Network

1 Radio transmitter with mechanical folding key

A8 Central locking control module

A19 Convenience locking system control module

A25 Radio frequency remote control + immobilizer control module

P11 Data link connector

Y30 Shut-off valve

S80.35-1773-06

Engine 111

Interlinkage of components (connection, radio remote control, PEC engine control module via PWM)

PWM Pulse Width Modulation

1 Radio transmitter with mechanical folding key

A8 Central locking control module

A19 Convenience locking system control module

A25 Radio frequency remote control + immobilizer control module

P11 Data link connector

PEC PEC engine control module

On 638 model vehicles a stage 2 drive authorization system (DAS) can be installed as special equipment. DAS is intended to prevent the engine from being started without authorization. Activation of the drive authorization system is accomplished in this case by the RF remote control/immobilizer control module. The immobilizer controlled by the RF remote control consists primarily of the electronic control circuitry in the vehicle and the folding vehicle key with integrated transmitter.

Engine 601
After activation of the DAS system the DSV engine control module shuts off the fuel supply to the injection pump. Data transmission between the DSV engine control module and RFL + IMM control module is accomplished via the CAN bus. The RFL + IMM control module and engine control module are permanently associated with one another by an identification code communicated via the CAN bus. This identification cannot be erased. For this reason it is not possible to replace the RFL + IMM control module or engine control module with the corresponding modules from another vehicle for checking.
Engine 111
After activation of the drive authorization system the PEC control module disables the ignition and injection systems. The start enable is accomplished by a PWM signal from the RFL + IMM control module to the PEC control module.

-----------------------------------------------------------------------------------------

 When PEC control modules are replaced for testing note that always control modules with integrated immobilizer are installed.

The drive authorization system is activated

-by locking the vehicle with the radio frequency remote control

-by locking the vehicle with the key via the central locking feature

-by automatic reactivation (when vehicle has been unlocked with the aid of the radio frequency remote control, however, none of the doors is opened within 10 min.).
If the ignition is switched on within 10 min. after deactivation with the radio frequency remote control, automatic activation is not accomplished.

Engine 601/CAN version
The indicator lamp comes on:

- When the immobilizer is activated by switching on the ignition

- When a motor "enabled" status is not signaled by the electronic engine circuitry within 1 s after switching on the ignition

The indicator lamp is switched off:

- When the ignition is switched off

- After receipt of the engine "enabled" status

---------------------------------------------------------------------------------------

Engine 111/PWM version
After switching on the ignition the indicator lamp comes on for at least 2 seconds.

The indicator lamp is switched off:

- 2 seconds after switching the ignition "on", when the immobilizer is deactivated.

- When a "short-circuit" is present at the output.

- When the ignition is switched on.

-----------------------------------------------------------------------------------------

The immobilizer can only be deactivated with the remote control with the "deactivate" signal (folding key out).

 Generally spare batteries should be present in the vehicle.

 Opening the vehicle with the mechanical key has no effect on the drive authorization system.

-----------------------------------------------------------------------------------------

Replacing components in the radio frequency remote control for central locking (vehicles with stage 2 drive authorization system)



The radio frequency remote control + immobilizer control module and the engine control module are permanently associated with one another by an identification code. For this reason the radio frequency remote control locking mechanism number part must remain in the vehicle for the entire service life of the vehicle; this means that it is possible to change only the mechanical locking mechanism number part as well as the check digit.

-----------------------------------------------------------------------------------------

Alternating code
The system operates with an alternating code as a protection against manipulations such as recording the signal, etc.
Each time the button is pressed a new remote control code is generated. The initial basis for the remote control code is the fixed code and a progressive code.
The fixed code consisting of 4 bytes is programmed in two remote controls as well as in the control module by the manufacturer.
The progressive code also consisting of 4 bytes is updated each time a button on the remote control is pressed, i.e. an addition constant is added. A unique 8-byte remote control code is generated by a coding algorithm using the fixed code and progressive code.

-----------------------------------------------------------------------------------------

2 497580 0 1039030 7

1st position

Profile identification

2nd - 7th position

Mechanical locking

mechanism

number part

9th - 15th position

Radio remote control locking mechanism number part

16th position

Test number

8th position

Supplier

0, 1  Huf

Structure of a locking mechanism number

This means when a remote control key or mechanical key is lost:

 The RCL locking mechanism number part remains the
same  lost keys are rendered unusable by desynchronizing the control module or revocably disabling the affected remote control key.

 Changing mechanical locking mechanism part number  installing complete new mechanical locking system with new locking system number. Always change the new mechanical locking system number part in the corresponding system (FDOK). The operating procedure will be announced later.

-----------------------------------------------------------------------------------------

This means when the RCL + IMM control module is defective:

 RCL locking mechanism number part remains the same  install new control module with same locking system number.

This means when a mechanical locking part is defective:

 Locking system number remains the same  replace locking part using part with same lock number.

-----------------------------------------------------------------------------------------

S80.35-1774-01

All vehicles are delivered from the factory with transmitter key "1" and "2". Any consequently numbered transmitter keys subsequently purchased should also be taken into account.

The transmitter keys still available can be identified by the numbers stamped on the transmitter key housing. Remove the battery compartment lid on the transmitter keys and read off the identification numbers.

 Keys which are subsequently ordered have a notch in the key bit.



With the CAN version it can be established using the HH tester which and how many keys are still released or even immobilized. This is not possible with the PWM version.