Starting System: Description and Operation

GF15.30-P-3000GK Starter Control, Function
ENGINE 273 in MODEL 463.202 /222 /236 /237 up to 31.5.12 as of Model Year 2009 /YoM 08





1 Circuit 50, status
2 Selector lever position, status
3 Starter relay, actuation
4 Starter, actuation
A8/1 Transmitter key
B11/4 Coolant temperature sensor
B70 Crankshaft Hall sensor
M1 Starter
N3/10 ME-SFI [ME] control unit
N10/1kS Starter relay
N73 EIS [EZS] control unit
Y3/8 Electric controller unit (VGS)
CAN C Drive train CAN

Function requirements for starter control, general points
^ Circuit 87M ON (engine control ON)
^ Engine Off
^ Start enable drive authorization system stage 3 (FBS 3)
^ Engaged gear range "P" or "N"

Starter control, general points
The starter control which is integrated in the ME-SFI [ME] control unit takes over actuation and shutoff of the starter.
For the starter control, the ME-SFI [ME] control unit reads the following sensors and signals:
- Coolant temperature sensor
- Crankshaft Hall sensor, engine speed
- EIS control unit, circuit 50 signal via the drive train CAN
- Electric controller unit (VGS), gear range via the drive train CAN

Starter control function sequence
The function sequence is subdivided into the following steps:
^ Start function sequence
^ End of start function sequence

Start function sequence
Through actuation of transmitter key in the start position the ME-SFI [ME] control unit receives the circuit 50 signal from the EIS control unit via the drive train CAN.

It reacts by actuating the starter relay with a ground signal. The power contact on the starter relay closes and the starter solenoid switch is supplied at "circuit 50" with voltage from "circuit 30".

End of start function sequence
Start control is carried out automatically by the ME-SFI [ME] control unit (touch start). This means that if the start process is initiated, switching off "circuit 50" has no further influence on the start process.
On reaching an engine cranking speed of n = 400 to 700 rpm or a starting time of approx. 5 to 40 seconds (depending on the coolant temperature), the ME-SFI [ME] control unit interrupts negative activation to the starter relay and thus ends the starting procedure.

The start sequence can only be aborted by switching off the ignition.