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

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

ENGINE 651.9 in MODEL 218 as of model year 2014 

IMPORTANT

The ECO start/stop function is subdivided into the engine-side and the on-board network side scope.

The "Engine management, start/stop function" subfunction is examined from the point of view of the engine management.

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

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

Engine management start-stop function, general 

For a stationary vehicle, the ECO 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 cutting out 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 status of the other components involved is read in from the front SAM control unit with fuse and relay module (N10/1) either directly or via chassis CAN 1 (CAN E1). The stop request is sent to the CDI control unit via chassis CAN 1.

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

Engine management Start-Stop function, function sequence 

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

Function sequence for automatic engine stop 

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

The following control units read in the following sensors and signals for fulfillment of the function requirements:

IMPORTANT

After an automatic engine stop a maximum of three automatic engine stops 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.

Upon opening of the engine hood in automatic engine stop, the ECO start/stop function is switched off and all indicator lamps in the IC light up. The engine must be restarted using the transmitter key or over the start/stop button KEYLESS-GO (with code (889) Keyless Go).

Function sequence for automatic engine start 

With a manual transmission, the engine is automatically started upon actuating the acceleration or clutch pedal. With dual clutch transmission, the engine is automatically started upon releasing the brake or operating the accelerator pedal.

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". Via the drive train CAN, the fuel system control unit receives the CAN signal "Fuel specified pressure" from the CDI control unit and actuates the fuel pump (M3) accordingly.

Function sequence for forced engine start (a start dictated by the system) 

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 start requirements occurs:

IMPORTANT

A maneuvering process is recognized for an engaged reverse gear and the ECO start/stop function is deactivated. If the engine is stopped it is force started by the system and the engine stop function is suppressed if it is running. The ECO start/stop function is subsequently activated again for an engaged forward gear and for exceeding a vehicle speed 15 km/h.

The engine is also started if the driver door is opened, the driver seat belt buckle is opened or the ECO start/stop function is switched off via the ECO start/stop function button.

  Function schematic for start-stop engine timing ENGINE 651.9 in MODEL 207 as of model year 2014 PE07.10-P-2722-97EAN
ENGINE 651.9 in MODEL 212 (except 212.098/298) as of model year 2014 PE07.10-P-2722-97DAR
ENGINE 651.9 in MODEL 218 as of model year 2014 PE07.10-P-2722-97XAH
  Overview of system components for common rail diesel injection (CDI)   GF07.16-P-9997OM 
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