Starting, Function - GF07.10-P-1001KJ

ENGINE 281.910 in MODEL 453.0/3/4 

Starting function requirements, general points 

• Circuit 87 (Engine management ON)
• Engine OFF
• Start enable via ME-SFI [ME] control unit (N3/10)
• Engaged gear range "P" or "N" (for code 429 (twinamic))
• Press brake pedal
• Fully push down on the clutch pedal and engage neutral (for code 410 (5-speed manual transmission))

Starting, general points 

The ME-SFI [ME] control unit reads in the following signals for starting:

• Intake camshaft Hall sensor (B6/15), intake camshaft setting for ignition circuit detection
• Coolant temperature sensor (B11/4)
• Crankshaft position sensor (L5), engine speed

For vehicles with code 494 (USA version) or code 460 (Canada version) the ME-SFI [ME] control unit also receives the start authorization from the DKG control unit (N15/13).

The center SAM control unit (N10/10) also reads the following signals for start enable:

• Transponder coil (L11) of the electronic immobilizer
• Clutch actuated over the clutch pedal switch start enable (S40/5) (for code 410 (Manual transmission, 5-speed))
• Also for code 494 (USA version) or code 460 (Canada version); neutral over the reversing light activation/idle recognition switch (S29/5) (for code 410 (Manual transmission, 5-speed))
• Also for code 429 (twinamic); the start authorization in the CAN message "Start_CrankingAuthorization_AT" via the interior CAN from the DKG control unit (N15/13)

The ME-SFI [ME] control unit coordinates start of the injection and firing order during starting based on the signals from the crankshaft position sensor and the intake camshaft Hall sensors.

The starter control in the ME-SFI [ME] control unit transmits the message "CrankingAuthorization_ECM" for the start enable via interior CAN (CAN B) to the center SAM control unit. The center SAM control unit reacts by actuating and cutting out the starter (M1).

The ME-SFI [ME] control unit actuates the following assembly parts to start the engine:

• Cylinder 1 ignition coil (T1/1) to cylinder 3 ignition coil (T1/3)
• Remove cylinder 1 injection valve (Y62/1) to cylinder 3 injection valve (Y62/3)
• Fuel pump with fill level sensor and temperature sensor (M3/3) via the ignition coils/fuel pump actuation relay (F11k3)

Function sequence for start 

The starter control is subdivided into the following points:

• Function sequence for start begin 
• Function sequence for start end 

Function sequence for start begin 

Through actuation of the ignition key (A8/1)) in ignition lock (S2) the ignition lock transmits the "circuit 50 signal" via the FIR fuse and relay module (F2), center SAM control unit and interior CAN (CAN B) to the ME-SFI [ME] control unit. The ME-SFI [ME] control unit reacts by transmitting the start enable via interior CAN to the center SAM control unit which actuates the starter relay (F2k5) upon fulfillment of the previously mentioned function requirements and therefore the starter.

Function sequence for start end 

The starter control takes place by the ME-SFI [ME] control unit which transmits the engine status or the engine rpm in the message "EngineStatus_R" via interior CAN to the center SAM control unit. The start process is then interrupted by the center SAM control unit. The start process itself can only be aborted by switching off the ignition.

	Electrical function schematic for starting		PE07.10-P-2701-97BBA
	Overview of system components motor electronics (ME-SFI) fuel injection and ignition system		GF07.61-P-9997KJ