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Engine timing start-stop function - GF07.10-P-1041OM

MODEL 204 with ENGINE 651.9 with CODE B03 (ECO start/stop function) 

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

MODEL 218 with ENGINE 651.9 up to model year 2014 

IMPORTANT The partial function "engine timing, start/stop function" is viewed in terms of the engine timing system.

Information for partial function "Energy management, start/stop function" is documented in the function description "Energy management function".

IMPORTANT In the partial function "Control of the climate control function" the function of the following components is described in more detail:

Function requirements for engine timing, start/stop function, general points 

engine timing, start/stop function, general points 

For a stationary vehicle, the start/stop function switches the engine off automatically and starts it again, as soon as the driver wishes to drive off. The fuel consumption and thus the exhaust emissions are reduced by stopping the engine with the vehicle at a standstill.

Conventional cut out and starting of the engine with the transmitter key (A8/1) or via the Start/Stop button KEYLESS-GO (S2/3) (with code (889) Keyless Go) continues to be possible.

The CDI control unit (N3/9) permanently performs a system diagnosis and assesses the function requirements for the start/stop function. The front SAM control unit with fuse and relay module (N10/1) also checks the function of all involved components and transmits the status to the CDI control unit via the chassis CAN (CAN E).

If the function requirements are fulfilled, the driver is notified of start/stop readiness by the "ECO" symbol in the multifunction display (A1p13) in the instrument cluster (A1).

For the start/stop function the CDI control unit reads in the following sensors and signals:

IMPORTANT The Electronic Stability Program control unit will be used in service as of 1.3.2011 (model 204.0/2.) or as of 1.6.2011 (model 204.3) in 2 variants:

Until 28.2.2011 (model 204.0/2.) or 31.05.2011 (model 204.9) and as of 1.6.2011 (model 204.9) only the basic variant of the Electronic Stability Program control unit will be used.

engine timing, start/stop function, function sequence 

The start/stop function consists of the following partial functions:

Function sequence for engine stop 

The engine is switched off by the CDI control unit if all of the following function conditions are fulfilled:

IMPORTANT After an automatic engine stop a maximum of three automatic starts are permitted without exceeding the speed threshold of 8 km/h. After the fourth engine start, the vehicle must exceed a speed of 8 km/h for the engine to be stopped again.

Function sequence for engine start 

When actuating the accelerator or clutch pedal (for manual transmission) or when actuating the accelerator pedal (for automatic transmission), the engine is started automatically.

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

The power contact on the relay closes and the starter solenoid switch (M1) is supplied at "circuit 50" with a voltage from "circuit 30".

The fuel system control unit receives the CAN signal "fuel specified pressure" from the CDI control unit via the drive train CAN and appropriately actuates the fuel pump (M3) by means of a pulse width modulated signal (PWM signal).

Function sequence for forced engine start 

The forced engine start subfunction is available as a protection function. Here the engine is force started autonomously (without any action taken by the driver) by the CDI control unit if one of the following function requirements occurs:

Communication error of the start/stop function with one of the following systems: suspension and steering functions, energy management, brake and control systems

IMPORTANT For an engaged reverse gear (for a manual transmission) or engaged gear range "R" (for an automatic transmission), a maneuvering process is recognized and the ECO start/stop function is deactivated.

If the engine is stopped it is force started, and if it is running the engine stop function is suppressed.

The ECO start/stop function is subsequently activated again when a forward gear is engaged (with a manual transmission) or gear range "D" is engaged (with an automatic transmission) and a vehicle speed of 15 km/h is exceeded. The engine is also started if the driver door is opened, the seat belt buckle for the driver opened or the ECO start-stop function over the ECO button is switched off.

  Electrical function schematic for engine timing, start/stop MODEL 204 PE07.10-P-2722-97FAE
  Electrical function schematic for engine timing, start/stop MODEL 207 PE07.10-P-2722-97EAE
  Electrical function schematic for engine timing, start/stop MODEL 212 PE07.10-P-2722-97DAE
  Electrical function schematic for engine timing, start/stop MODEL 218 PE07.10-P-2722-97XAD
  Overview of system components for common rail diesel injection (CDI)   GF07.16-P-9997OM 
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