The ME-SFI start quantity control function - GF07.61-P-3010V

ENGINE 272.942 in MODEL 171 

ENGINE 272.963 in MODEL 171 

Shown on engine 272.963 in model 171 

Fig 1: ME-SFI Start Quantity Control Function Diagram - Shown On Engine 272.963 In Model 171

Courtesy of MERCEDES-BENZ USA

The start quantity control must guarantee the safe start of the engine. To do this, a decision is made as to whether this is a cold start, a warm start, a repeat start or a start following operation of the stationary heater.

In order to facilitate starting a cold engine, in addition fuel must be

The start quantity control is enabled after start recognition. It remains activated until a temperature related engine speed is exceeded.

The higher the coolant temperature, the lower is the start quantity enable by the ME-SFI control unit.

injected during the starting procedure, depending on the coolant temperature. The increased quantity of fuel injected is achieved by extending the injection time.

The start quantity control is dependent on:

• Start identification (CAN message "Terminal 50 ON")
• Coolant temperature
• Engine speed
• Following operation of the stationary heater, in addition to the external air temperature when the engine was last shut-off (CAN message from the instrument cluster), intake air temperature and shut-off time of the engine.