Safety and Gateway Module

The Safety and Gateway Module transmits signals and messages on the following bus systems:

• Serial diagnostic cable
  
• BYTEFLIGHT
  
• PT-CAN (Powertrain CAN)
  
• K-CAN (body CAN)
  

The connection between the diagnosis system and the vehicle is exclusively via the Safety and Gateway Module. The Safety and Gateway Module is connected by means of the OBD (on-board diagnosis) connector via a serial copper lead (= diagnosis lead). The diagnostic head of the BMW diagnosis system is connected at the OBD plug. The BYTEFLIGHT fibre-optic bus is assigned to the safety system (e.g. airbags). The PT-CAN bus is used for engine-related functions and the System K-CAN bus for body-zone functions.

Wake-up and Sleep conditions:

• The Safety and Gateway Module can 'go to sleep' (switch off the internal power supply) if
  
  • the PT wake-up line signal is not ”High”
    
  • there are no wake-up signals present on the BYTEFLIGHT fibre-optic bus
    
  • there is no activity on the K-CAN bus
    Sleep mode readiness is initiated simultaneously for all buses if all nodes of all the bus systems connected to the Safety and Gateway Module indicate readiness, the PT wake-up line signal is not at ”High” and the diagnosis lead is not being operated externally. The Safety and Gateway Module prevents individual buses on which all nodes are ready to switch to Sleep mode from switching to Sleep mode if at least one node an another bus is not ready for Sleep mode.
    
• The Safety and Gateway Module is wakened (internal voltage switched on) if
  
  • the PT wake-up line signal is ”High”
    
  • a wake-up signal is detected on the BYTEFLIGHT fibre-optic bus
    
  • a message is received on the K-CAN bus
    
  • a power-down reset is initiated by Terminal 30
    

The Safety and Gateway Module wakes up the K CAN bus, PT CAN bus via the wake-up line and the BYTEFLIGHT bus if one of the buses is woken up.

Note:

The control units on the PT-CAN bus have a separate wake-up line. The control units on the PT-CAN bus are woken up by a High level (pulse duration of approx. 500 ms, minimum of 5 V) signal on the wake-up line. If the ignition is switched on (i.e. terminal 15 On), there is a constant voltage between 9 V and 16 V on the wake-up line.

Function test of the Safety and Gateway Module

The subsequent operational test indicates whether the Safety and Gateway Module is operating properly.

• Transmission PT-CAN to K-CAN (requirement: running engine): If the transmission is OK, the engine speed is shown in the instrument cluster. (Signal path: Digital Engine Electronics - PT CAN - Safety and Gateway Module - K CAN SYSTEM - Instrument Cluster).
  
• Transmission BYTEFLIGHT to K-CAN (requirement: ignition on): if the transmission is OK, the wiper is activated when the wiper switch is operated. (Signal path: Steering column switch cluster - BYTEFLIGHT- Safety and Gateway Module - K-CAN - Body base module(E60) or wiper module (E65).
  

If the above operational test is OK, then there is high probability that the Safety and Gateway Module is in proper working order.