GF07.61-P-2007CY | ME-SFI idle speed control, function | 20.3.08 |
ENGINES 272.911 in MODEL 204.0 up to Model Year 08 /Modification Year 07
ENGINES 272.921 in MODEL 204.0 /2 up to Model Year 08 /Modification Year 07
ENGINES 272.947 in MODEL 204.0 /2 up to Model Year 08 /Modification Year 07
ENGINES 272.948 in MODEL 204.0 up to Model Year 08 /Modification Year 07
ENGINES 272.961 in MODEL 204.0 /2 up to Model Year 08 /Modification Year 07
ENGINES 272.971 in MODEL 204.0 up to Model Year 08 /Modification Year 07
The throttle valve actuator (M16/6) regulates the idle speed by adjusting the throttle valve position. It is actuated by the motor electronics control unit (N3/10).
To assist idle speed control, the ignition angle can be retarded by as much as a 36° crank angle and advanced by as much as a 20° crank angle.
Corresponding to its input signals the ME-SFI [ME] control unit controls the idle speed in the warm-up phase and for different engine loads (e.g. gear range engaged, A/C compressor (A9) switched on).
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Warm-up phase (heating speed)
In order to bring the catalytic converters to operating temperature more quickly, the idle speed is raised to approx.1100 to 1300 rpm for approx. 20 seconds if:
Coolant temperature <40°C
Engine start has occurred
After this time elapsed, the idle speed is increased at a coolant temperature <70°C depending on the temperature for about 50 seconds by about 50 to 100 rpm.
The increase will be canceled when a gear range is engaged.
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with automatic transmission 722.9
When a drive position is engaged, a lower engine speed is controlled in order to reduce the creeping tendency of the vehicle.
The information "Gear range engaged" is conveyed to the ME-SFI [ME] control unit via the drive train CAN (CAN C) by the electronic selector lever module control unit (N15/5).
For manual transmission 716.6
When actuating the clutch pedal the idle speed is stabilized. The operation of the clutch pedal is detected by the ME-SFI [ME} control unit through the clutch pedal switch (S40/3).
Refrigerant compressor (A9)
So that at idle the engine speed does not drop when the A/C compressor is switched on, the automatic air conditioning control and operating unit (N22/7) transmits a signal to the ME-SFI [ME} control unit via the interior CAN (CAN B) and chassis CAN (CAN E) before the A/C compressor is switched on. This responds by adjusting the idle speed appropriately.
Undervoltage of on-board electrical system battery (G1)
If the ME-SFI [ME] control unit detects an undervoltage, the idle speed is increased until the ignition is switched off for the driving mode selected at around 100 rpm.
Adjusting the ignition angle enables a faster response than adjusting the throttle valve.
The basic setting of idle speed can be influenced with the DAS [Diagnosis Assistance System]
| Electrical function schematic for idle speed control | ||
Fuel injection valves, component description | Y62/1-Y62/6 | ||
Component description for coolant temperature sensor | B11/4 | ||
Crankshaft Hall sensor component description | B70 | ||
ME-SFI [ME] control unit, component description | N3/10 | ||
Ignition coils, component description | T1/1-T1/6 | ||
Component description for the clutch pedal switch | S40/3 For manual transmission 716.6 S40/5 For manual transmission 716.6 With code 494 USA version | ||
Component description for accelerator pedal sensor | B37 | ||
Component description for the throttle valve actuator | M16/6 |
Referenced documents
- gf0703p6010cy Component description for the fuel injection valves
- gf0704p6043cy Component description for the coolant temperature sensor
- gf0704p6221cy Component description for the crankshaft Hall sensor
- gf0761p6000cy Component description for the ME-SFI [ME] control unit
- gf1510p2100cy Component description for ignition coils
- gf2910p2200cy Component description for clutch pedal switch
- gf3020p2011cy Component description for accelerator pedal sensor
- gf3020p2021cy Component description for the throttle valve actuator