LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercedes Benz >> 2013 >> E300 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Mixture Formation - 212 Chassis - 01 Of 10 >> Basic Knowledge >> Starting, function >> Starting, function - GF07.10-P-1001OMA
April 5, 2026: LEMON Manuals is launched! Read the announcement.

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

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 

Starting function requirements, general points 

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 signals:

The CDI control unit coordinates the injection sequence during starting based on the signals from the crankshaft Hall sensor and from the camshaft Hall sensor.

The CDI control unit actuates the following components to start the engine:

IMPORTANT Fuel pump actuation

The fuel system control unit (N118) is actuated over the drive train CAN to actuate the fuel pump.

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 

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 chassis CAN 1.

The CDI control unit actuates the circuit 50 starter relay (N10/1kM) (two-pin, high/low). The power contact on the starter relay closes and the starter solenoid switch is supplied at "circuit 50" with voltage from "circuit 30".

IMPORTANT If the CDI control unit detects that the engine is running via the crankshaft Hall sensor and the message "circuit 61 ON" and that the starting procedure has ended via the message "circuit 50 OFF", the driver will then be able to influence the injection quantity and thus the engine speed via the accelerator pedal sensor.

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 (dependent 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 negative actuation to the circuit 50 starter relay and thus terminates the starting procedure.

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

IMPORTANT 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).

IMPORTANT ENGINE 651.9 in MODEL 207, 212 (except 212.098/298) as of model year 2014 with CODE U42 (BlueTEC diesel exhaust treatment (SCR)) with CODE U77 (Diesel Emission control BLUETEC (SCR))

ENGINE 651.9 in MODEL 218 as of model year 2014 with CODE U77 (Diesel Emission control BLUETEC (SCR))

For vehicles with BLUETEC (SCR) diesel exhaust treatment, no start enable is issued from the AdBlue® control unit (N118/5) if the AdBlue® tank is empty and the number of permissible engine starts with an empty AdBlue® tank is at zero.

  Electrical function schematic for starting ENGINE 651.9 in MODEL 207 as of model year 2014 PE07.10-P-2701-97EAN
ENGINE 651.9 in MODEL 212 (except 212.098/298) as of model year 2014 PE07.10-P-2701-97DAR
ENGINE 651.9 in MODEL 218 as of model year 2014 PE07.10-P-2701-97XAH
  Overview of system components for common rail diesel injection (CDI)   GF07.16-P-9997OM
scientia non olet · About LEMON Manuals