ME-SFI warm-up control, function - GF07.61-P-3022M

ENGINES 275.950 in MODEL 215, 220

ENGINES 275.951 in MODEL 230 up to Model Year 08/Modification Year 07

ENGINES 275.953 in MODEL 216, 221 up to Model Year 08/modification year 07

ENGINES 275.954 in MODEL 230 up to Model Year 08/Modification Year 07

ENGINES 275.980 in MODEL 215, 220

ENGINES 275.981 in MODEL 230 up to Model Year 08/Modification Year 07

ENGINES 275.982 in MODEL 216, 221 up to Model Year 08/modification year 07

ENGINES 285.950 in MODEL 240

ENGINES 285.980 in MODEL 240

Fig 1: ME-SFI Warm-Up Control Function Diagram

Courtesy of MERCEDES-BENZ USA

Fig 2: Enrichment Rate Graph

Courtesy of MERCEDES-BENZ USA

Task

After start- and post-start enrichment the air/fuel mixture is further enriched by the warming-up control as part of the air/fuel mixture precipitates on the parts of the engine which are still cold.

The additional quantity of fuel is metered to the engine by the ME control unit (N3/10) in line with the performance map. The injection time is extended accordingly for this purpose.

The warming-up enrichment is dependent on:

Coolant temperature
Charge pressure control
Engine speed
Engine load
Idle speed/part load operation
Correction programming with STAR DIAGNOSIS

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