2008 Mercedes Benz E320FACTORY OEM SERVICE PROCEDURE

CDI starting, function - GF07.16-P-2001P

ENGINE 642 in MODEL 203.0/2, 221.0/1 up to Model Year 8 

ENGINE 642 in MODEL 209.3/4, 211.0/2/6, 219.3 

During the starting procedure the common rail diesel injection (CDI) regulates the following functions via the CDI control unit (N3/9):

  • Preglowing
  • Actuation of fuel pump (M3)
  • Start-readiness glowing
  • Starter control
  • Synchronization of injection sequence
  • Start-glowing
  • Start quantity control
  • Afterglowing

Preglowing 

For the start it is necessary to heat the glow plugs (R9) to a temperature, which heats the combustion chambers and which enables the fuel to ignite at the designated time.

Actuation of fuel pump 

The CDI control unit actuates the fuel pump via the fuel pump relay (N10/2kA) (model 203.0/2, model 209.3/4, model 211, model 219.3) or the fuel pump relay (N10/2kS) (model 221.0/2) integrated in the rear SAM control unit with fuse and relay module (N10/2). The following preconditions must be given:

  • "Engine start" from drive authorization system, stage 3 (DAS [FBS] 3)
  • Circ. 50 ON
  • Selector lever position P or N

Start-readiness glowing 

This serves to ensure that following preheating a sufficiently high combustion chamber temperature is given until the engine is started.

Starter actuation in model 203, 209, 221 

Depending on the following information the CDI control unit actuates the starter (M1) via the starter relay (N10/1kS) (model 203, 209) or circuit 50 relay, starter (N10/1kH) (model 221) integrated in the front SAM control unit with fuse and relay module (N10/1):

  • DAS 3 [FBS] start approval information from the EIS [EZS] control unit (N73)
  • Circ. 50 ON
  • Selector lever position P or N

Starter actuation in model 211, 219 

Depending on the following information the CDI control unit actuates the starter (M1) over the starter relay (N10/1kL) integrated into the driver-side SAM control unit with fuse and relay module (N10/1):

  • DAS 3 [FBS] start approval information from the EIS [EZS] control unit (N73)
  • Circ. 50 ON
  • Selector lever position P or N

Synchronization of injection sequence 

In order to achieve correct synchronization of the fuel injection sequence to the respective cylinder, the sequence is synchronized during the engine's first revolutions. To detect the 1st. cylinder the CDI control unit requires the signal from the camshaft Hall sensor (B6/1) and the signal from the crankshaft Hall sensor (B70).

Start-up glowing 

This function serves to ensure that during the starting procedure the first working cycles and the engine startup are supported.

IMPORTANT If during the engine start a signal has not been received from the camshaft Hall sensor, then the engine will not start.

Start quantity control 

During the engine start the CDI control unit draws on the coolant temperature and motor speed to determine the start quantity and then actuates the quantity control valve (Y94), pressure regulator valve (Y74) and the fuel injectors (Y76).

After-glowing 

This function serves to ensure that once the engine has started combustion is given map-controlled support.

CDI fuel supply, function   GF07.16-P-2006P 
CDI start quantity control, function   GF07.16-P-3000P 
CDI fuel low pressure circuit, function   GF07.16-P-3001P 
CDI quantity control, function   GF07.16-P-3004P 
CDI high pressure circuit, function   GF07.16-P-3012P 
CDI preglow function Model 164, 203, 209, 211, 219, 251 GF15.20-P-3004P
Model 221 GF15.20-P-3004SX
Starter control, function Model 203, 209, 211, 219 GF15.30-P-3000P
Model 221 GF15.30-P-3000SX
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.