Electronic ignition/starter switch control unit (EZS), component description

D80.57-1111-12

N73 EIS [EZS] control unit

Location

The EIS control unit is located on the right next to the steering column in the instrument panel

Task

The EIS [EZS] control unit is the master control unit for central locking (CL). The tasks of the EIS [EZS] control unit are as follows:

 Interface (gateway) between Controller Area Network bus class B (interior) (CAN-B) and Controller Area Network bus class C (engine compartment) (CAN-C) for drive authorization relevant data

 Encrypted bi-directional infrared remote control (IR) communication for key coding

 Encryption and decryption of data and performing authentication check for transmitter key (A8/1)

 Power transfer to transmitter key

 Reset from start position to drive position

 Limit switch for c. 15 and c. 15R

 Rotation angle dependent activation of individual signals

(e.g. C. 15C, C. 15R, C. 15, C. 15X, C. 50)

 Prefastening and holding of transmitter key in unturned position

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 Rotation lock of transmitter key by locking lift solenoid

 Closing key opening when transmitter key is removed

Access authorization

The vehicle is locked and unlocked by the radio remote (transmitter key). The antenna with the terminal connector for the DAS wire antenna (A2/34-z1) for the radio signals is located in direction of travel behind the instrument cluster. The terminal connector for the wire antenna relays the signals to the EIS [EZS] control unit via a discrete line.

On vehicles without comfort opening/closing with IR

The EIS control unit performs authentication and sends the message "Unlock CL" or "Lock CL" to the CAN-B.

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On vehicles with comfort opening/closing with IR

The infrared signals are read in by the driver door IR receiver (A26/1) and relayed to the driver door control unit (N69/1). The driver door control unit receives the authentication codes from the EIS control unit via CAN-B and compares these with the signals received from the driver door IR receiver. If both coincide, the infrared signals are converted into CAN messages and relayed to the EIS control unit. The EIS control unit then sends the command "Unlock CL" or "Lock CL" to the CAN-B.

Drive authorization

The vehicle cannot be started before successful infrared communication in the EIS control unit. By inserting the transmitter key in the EIS [EZS] control unit, i.e. "Circuit 15C ON", the electronic circuit is woken up from the "Sleep mode" and the power is supplied to the transmitter key by the EIS [EZS] control unit. The transmitter key is identified by bi-directional data exchange.

After successful identification, all participating control units are released via the CAN-B.

After successful communication, the following functions are accomplished in addition:

 Enabling locking solenoid via ESL control unit (N26/5).

 Switch on transmitter key position recognition