Communication with central locking (CL)
Command telegrams are transmitted to the central locking system and status telegrams received from the central locking system via a single wire bus.
The following are defined as command telegrams:
Unlock vehicle
Lock vehicle
The following are defined as status telegrams:
Vehicle unlocked
Vehicle locked
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A command telegram to the central locking system is initiated when the ignition is off and a valid telegram is received by a remote control key.
The new status (unlocked/locked) must be the opposite of the previous status. The central locking system replies to a command telegram after max. 1.5 s (unlock) or 3 s (lock) with a status telegram.
A new command telegram is transmitted only after receipt of a status telegram or after expiration of a waiting time of 1.5 s or 3 s.
A status telegram can be received from the central locking system at any time.
Note
If the waiting times specified above are not maintained, e.g. the key is opened or closed too quickly, the position of the key may not coincide with the vehicle status (unlocked/locked).
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Communication with the anti-theft alarm system (ATA)
On vehicles with anti-theft alarm, the ATA control module is located between the RRC control module and CL control module.Command telegrams from the RRC control module are relayed by the ATA control module to the CL control module.In the opposite direction, status telegrams are transmitted from the CL control module to the ATA control module and from there relayed to the RRC control module.
The anti-theft alarm is activated upon receiving the status telegram "Vehicle locked" from the CL control module.
The anti-theft alarm is deactivated when it receives a command telegram "Unlock vehicle" from the RRC control module.
Communication with PEC/DSV/MSA engine control modules
On vehicles with drive authorization system (DAS), the immobilizer is activated by a signal from the RRC control module to the engine control modules.
2 versions of the interface to the engine control modules are used:
PWM output with unidirectional communication (vehicles with engine 111)
CAN bus with bidirectional communication (vehicles with engine 601 / 602)