Starting, function - GF07.10-P-1001OM

ENGINE 651.9 in MODEL 204 

ENGINE 651.9 in MODEL 207, 212 (except 212.098/298) up to model year 2014 

ENGINE 651.9 in MODEL 218 up to model year 2014 

Starting function requirements, general points 

• Circuit 87M ON (engine timing ON)
• Engine OFF
• Drive authorization system 3 (DAS 3) start enable
• Engaged gear range "P" or "N" (on vehicles with automatic transmission)

Starting, general points 

The starter control system in the CDI control unit (N3/9) is responsible for actuation and shutoff of the starter (M1).

For starting, the CDI control unit reads the following sensors and signals:

• Oil temperature sensor (B1)
• Atmospheric pressure sensor, for acquisition of the atmospheric pressure
• Crankshaft position sensor (L5) (except code (B03) ECO start/stop function), for engine speed
• Rail pressure sensor (B4/6)
• Camshaft Hall sensor (B6/1)
• Coolant temperature sensor (B11/4) (model 204, 207, 212), coolant temperature sensor (B11/4) (model 218)
• Crankshaft Hall sensor (B70) (with code (B03) ECO start/stop function), for engine speed
• Circuit 61 signal (alternator (G2) functioning)
• Electronic transmission control unit (N15/3) (with code (423) 5-speed (NAT) A/T), gear range via the drive train CAN (CAN C)
• Electronic ignition lock control unit (N73), "circuit 50 signal" via the chassis CAN (CAN E)
• Fully integrated transmission control controller unit (Y3/8) (with code (427) 7-speed A/T), gear range via drive train CAN

The CDI control unit coordinates the injection sequence when starting using signals from the crankshaft position sensor (except code (B03) ECO start/stop function) and crankshaft Hall sensor (with code (B03) ECO start/stop function) and camshaft Hall sensor. The CDI control unit actuates the following components to start the engine:

• Starter
• Pressure regulating valve (Y74)
• Fuel injectors (Y76)
• Quantity control valve (Y94)
• Fuel pump (M3)

Fuel pump actuation over the fuel pump relay (N10/2kD) (model 204.0/9 up to 05/2009, model 212.0 up to 08/2009) or over the FSCU (N118) (model 204.0/9 as of 06/2009, model 204.2/3, model 207.3/4, model 212.0 as of 09/2009, model 212.2, model 218).

The start quantity control in the CDI control unit serves to calculate a specific start quantity at engine start irrespective of the position of the accelerator pedal sensor (B37).

Function sequence for start 

The function sequence is subdivided into the following steps:

• Function sequence for start begin 
• Function sequence for start end (with automatic transmission) 
• Function sequence for start end (with manual transmission) 

Function sequence for start begin 

When transmitter key (ignition key (A8/1)) is moved to the start position, the CDI control unit receives the "circuit 50 signal" from the electronic ignition lock control unit via the chassis CAN.

The CDI control unit actuates the circuit 50 starter relay (N10/1kM) by means of 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".

If the CDI control unit recognizes running of the engine based on the crankshaft position sensor (except code (B03) ECO start/stop function) and crankshaft Hall sensor (with code (B03) ECO start/stop function) and the message "Circuit 61 ON" and the fact that the starting operation has been terminated based on the message "Circuit 50 OFF", the driver can regulate the injection quantity with the accelerator pedal sensor thereby changing the engine speed.

Function sequence for start end (with automatic transmission) 

Starter control is carried out automatically by the CDI control unit (touch start). This means that once the start process is initiated, switching off "circuit 50" will have no further influence on the start procedure.

When the engine cranking speed has reached 400 to 700 RPM, or after a starting time of 5 to 40 s (depending on coolant temperature), the CDI control unit interrupts the negative activation of the circuit 50 starter relay and thus terminates the starting procedure. The starting procedure can only be aborted by switching off the ignition.

Function sequence for start end (with manual transmission) 

On reaching an engine cranking speed of 400 to 700 RPM or upon disappearance of the "circuit 50 signal", the CDI control unit interrupts the negative activation to the circuit 50 starter relay and thus terminates the starting procedure.

The starting procedure can also be aborted by switching off the ignition.

The starting procedure is inhibited for approximately 1.5 to 3 s before it can be repeated. This occurs so that the rotating pinion of the starter is prevented from meshing with the toothing on the engine clutch plate (ring gear protection).

	Electrical function schematic for Start	MODEL 204	PE07.10-P-2701-97FAE
	Electrical function schematic for starting	MODEL 207	PE07.10-P-2701-97EAE
	Electrical function schematic for starting	MODEL 212	PE07.10-P-2701-97DAE
	Electrical function schematic for starting	MODEL 218	PE07.10-P-2701-97XAD
	Overview of system components for common rail diesel injection (CDI)		GF07.16-P-9997OM