Starting, Function - GF07.10-P-1001MRD
Engine 274.9 in model 213 (except 213.050/053/153), 238
up to model year 2021
Function requirements, general
- Drive range "P" or "N" engaged and foot brake actuated (automatic transmission)
- Clutch and foot brake actuated (manual transmission)
The fully integrated transmission control unit (Y3/8n4) transmits information about the engaged gear range via the drive train CAN (CAN C1) to the ME-SFI [ME] control unit (N3/10).
The powertrain control unit (N127) directly reads in the clutch pedal sensor (B53/1) and transmits the clutch pedal travel via the drive CAN to the ME-SFI [ME] control unit.
The Electronic Stability Program control unit (N30/4) transmits the information on the service brake status via the suspension FlexRay (Flex E), powertrain control unit and drive CAN to the ME-SFI [ME] control unit.
Starting, general points
The ME-SFI [ME] control unit reads in the following signals for starting:
- Intake camshaft position for ignition circuit detection
Intake camshaft Hall sensor (B6/15)
- Exhaust camshaft position for ignition circuit detection
Exhaust camshaft Hall sensor (B6/16)
- Coolant temperature
Coolant temperature sensor (B11/4)
- Clutch pedal travel (manual transmission)
Clutch pedal sensor
- Engine speed
Crankshaft Hall sensor (B70)
- Circuit 50 status
The electronic ignition lock control unit (N73) directly reads in the signals of the KEYLESS-GO start/stop button (S2/3) and transmits the circuit 50 status via the suspension FlexRay, powertrain control unit and drive CAN to the ME-SFI [ME] control unit
- Oil level
Oil level check switch (S43)
- Drive position
The ME-SFI [ME] control unit actuates the following assembly parts to start the engine:
- Starter (M1)
- Cylinder 1 ignition coil (T1/1)
- Cylinder 2 ignition coil (T1/2)
- Cylinder 3 ignition coil (T1/3)
- Cylinder 4 ignition coil (T1/4)
- Cylinder 1 fuel injector (Y76/1)
- Cylinder 2 fuel injector (Y76/2)
- Cylinder 3 fuel injector (Y76/3)
- Cylinder 4 fuel injector (Y76/4)
- Fuel pump (M3)
The ME-SFI [ME] control unit transmits the request to actuate the fuel pump both directly and via the drive CAN to the fuel system control unit (N118); the ME-SFI [ME] control unit also transmits the specified fuel pressure via the drive CAN to the fuel system control unit. The fuel system control unit directly actuates the fuel pump.
The ME-SFI [ME] control unit coordinates the injection and firing order during starting based on the signals from the crankshaft Hall sensor and the intake camshaft and exhaust camshaft Hall sensors.
The starter control in the ME-SFI [ME] control unit takes on actuation and cutout of the starter.
Starter control
The starter control is subdivided into the following points:
- Start begin
- Ending start
Start begin
By actuating the KEYLESS-GO start/stop button, the ME-SFI [ME] control unit receives the "circuit 50 signal" from the electronic ignition lock control unit via the suspension FlexRay, powertrain control unit and drive CAN.
The ME-SFI [ME] control unit uses a ground signal to actuate the starter circuit 50 relay (K40/8kH) on both sides. The power contact on the starter relay closes and the starter solenoid switch is supplied at "circuit 50" with voltage from "circuit 30".
Ending start
Starter control is carried out automatically by the ME-SFI [ME] control unit (touch start). This means that once a starting procedure is initiated, deactivating "circuit 50" no longer has an influence on the starting procedure.
When engine cranking speed has reached 400 to 700 RPM, or after a starting time of 5 to 40 s (dependent on coolant temperature), the ME-SFI [ME] control unit interrupts the negative activation of the circuit 50 starter relay and thus terminates the starting procedure.
The start process can be broken off through renewed actuation of the KEYLESS-GO start-stop button.
| Electrical function schematic for starting | PE07.10-P-2701-97DBD | ||
| Overview of system components for gasoline injection and ignition system with direct injection | GF07.70-P-9998MRD |