GF07.61-P-5001M Voltage Supply of ME-SFI Control Unit, Function

GF07.61-P-5001M Voltage Supply Of ME-SFI Control Unit, Function

Component Identification:

Voltage supply
The ME-SFI control unit is supplied with voltage at circuits 87 and 30 as follows (fused/unfused):
Model 215, 220 from right front fuse and relay module (K40/7)
Model 230 from passenger-side fuse and relay module (K40/4)
Model 240 from driver-side SAM control unit with fuse and relay module (N10/1)

Ground connections of output stages
Several ground connections and the ground of the electronics are attached connected lose to the ME-SFI control unit (major assemblies compartment partition, wheelhouse or body).

The ME-SFI control unit features a short-circuit protection as well as a reversed polarity protection in the operating voltage section.

In certain cases voltage is supplied through several pins connected in parallel by means of bridges to relief the electrical connectors.

If the signal sent by the EIS control unit (N73) "Circuit 15 Fused On" is read in by the ME-SFI control unit (N3/10), the ground for the engine main relay is transmitted by actuation of a transistor. Once the engine main relay has closed the power contact, voltage flows through it from circuit 30 via two fuses as circuit 87 M to the ME-SFI control unit and the engine control. For the purpose of assigning consumers/ components to the two 20 A fuses, a distinction is made as to which consumers/components of the motor electronics are required or non- required for engine operation.

If the ME-SFI control unit receives the signal "circuit 15 fused OFF" from the EIS control unit, the computer run-on time is started. Once this run-on time has elapsed, the engine main relay is switched off and the ME-SFI control unit is thus isolated from the electrical system.

Voltage supply: refer to Wiring Diagrams, Group 54.