Relay Module: Description and Operation

Position
In engine compartment, in control module box or module box, respectively

Task
- Supplying voltage for control modules and electric components
- Protecting the electric circuit of control modules and electric components
- Actuating the engine control module in the event of ignition OFF







Function of ignition ON and engine running
With ignition ON the fuse and relay module (K40/4) and the engine control module are actuated. Relay K2 switches the battery voltage through fuse 3 to the engine control module. The voltage for the remaining components which form part of the IFI, DFI or CDI fuel injection system, is supplied through fuse 2.

Function of ignition OFF
With ignition OFF actuation is cancelled, but voltage continues to be supplied for about a further 4 seconds through contact B1.3 to the fuse and relay module (K40/4) by means of the holding relay circuit in the engine control module. The engine control module detects the voltage drop at circuit 15 and initiates engine stop.
Engine stop function:
DFI: by deenergizing the shutoff valve (Y23/2y1)
IFI: by deenergizing the fuel metering actuator (Y23/1)
CDI: by energizing the shutoff valve (Y75)