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ME-SFI idle speed control function - GF30.22-P-0003E

ENGINE 104.941 /943 /944 /991 /994 as of 1/8/96 

ENGINE 104.995 

with CODE (494a) USA version 

with CODE (807) Model year 1997 

with CODE (808) Model year 1998 

with CODE (498) as of Model year 97 Japanese version 

ENGINE 111.921 /942 as of 1.9.98, 

111.943, 

111.944 as of 1.8.96, 

111.946 as of 1.6.98, 

111.947/973, 

111.975 as of 1.8.96 

ENGINE 111.945 

in MODEL 208.335 /435 as of 1.6.98, 

202.020/080 as of 1.9.98 

ENGINE 111.974 

with CODE (494a) USA version 

with CODE (807) Model year 1997 

with CODE (808) Model year 1998 

ENGINE 112.910 /911 /912 /913 /914 /916 /917 /920 /921 /922 /923 /940 /941 /942 /943 /944 /946 /947 /949 /953 /954 /955 /970 /972 /973 /975 

ENGINE 113.940 /941 /942 /943 /948 /960 /961 /963 /965 /966 /967 /968 /969 

ENGINE 119.980 /981 /982 /985 

ENGINE 137.970 

Fig 1: Identifying ME-SFI Idle Speed Control Function Diagram
G04606724

Task 

Controlling idle speed in the case of

Function 

The actuator EFP/TPM/LLR (additional designation: throttle valve actuator) regulates the idling speed by changing the throttle valve position. It is actuated by the ME-SFI control unit.

The ME-SFI control unit actuates the throttle valve motor (M16/1 m1) in line with the input signals received at the ME-SFI control unit (N3/10).

Heating speed of the catalytic converter 

In order to warm up the catalytic converter more rapidly to operating temperature, engine speed is increased in the idle speed range to 1100 up to 1500 rpm for about 20 seconds after each starting procedure at coolant temperatures of < 40 °C. When a Drive position is engaged, engine speed is immediately controlled to a lower value.

Automatic transmission 

When a drive position is engaged, a lower engine speed is controlled in order to reduce the creeping tendency of the vehicle. The information "Drive position engaged/not engaged" is transmitted by the ETC control unit (N15/3) over the CAN databus to the ME-SFI control unit.

Ignition angle 

To assist the idle speed control, the ignition angle can be retarded by as much as 36° crank angle or advanced by as much as 20° crank angle from the calculated specified value.

IMPORTANT

The control in the idle speed range by altering the ignition angle reacts more rapidly than altering the position of the throttle valve.

The idling speed can be influenced with HHT or the STAR DIAGNOSIS.

AC compressor 

In order to avoid engine speed dropping in the idle speed range when the AC compressor is engaged, the AC push-button control unit (N19) or automatic air conditioning push-button control unit (N22) supplies a signal to the ME-SFI control unit (as of approx. 6/96 over CAN) and the opening cross-section of the throttle valve is enlarged.

When the air conditioning unit is switched on and the external temperature exceeds 35° C the idling speed on vehicles delivered from 6/00 is increased for the driving mode selected by about 100 rpm when the switch-on threshold of about 900 rpm is exceeded. This increase is cancelled again when the external temperature drops below 32° C.

Undervoltage 

If the engine control unit detects an undervoltage the idling speed is increased until the ignition is switched off for the driving mode selected by about 100 rpm.

If the control unit SBC reports an undervoltage to the engine control unit over CAN the idling speed for the driving mode selected is increased to about 750 rpm.

  Motor electronics control unit, location/task/ design/function   GF07.61-P-5000F
  ME-SFI ignition system function   GF15.12-P-0001F
  ECI ignition system function Engine 137 GF15.15-P-3000L
  Pedal value sensor, location/task/design/ function   GF30.20-P-4011L 
  Coolant temperature sensor, location/task/ design/function Engine 119, 120 GF07.04-P-5026F
Engine 104, 111 GF07.04-P-5026G
Engine 112, 113, 137 GF07.04-P-5026A
  Intake air temperature sensor, location/task/ design/function   GF07.04-P-2100F
  ME fuel supply function Engine 104, 111, 119, 120 in Model 129, 140, 170, 202, 208, 210 GF07.61-P-3004F
Engine 112, 113, 137 (except in Model 203, 209, 211) GF07.61-P-3004A
Engine 112.91/94/95 203
Engine 112.91/94/95, 113.96 in Model 211
Engine 112.912/955, 113.968 in Model 209
GF07.61-P-3004P
  Crankshaft position sensor, location/task/ design/function   GF07.04-P-4116F
  Electronic accelerator/cruise control/idle speed control actuator location/task/design/function   GF30.22-P-4010F 
  Electronic accelerator pedal emergency running mode function Engine 120.98 GF30.20-P-4026F
Engine 104, 111, 112, 113, 119, 137 GF30.20-P-4026E 
  ME-SFI TWC heating-up function   GF07.61-P-3032F
  ETC control unit, location/task Information on selector lever position P/N and gear engaged in the case of automatic transmission.
Transmission 722.6
GF27.19-P-4012G
  Clutch pedal switch, location/task/function with MT GF29.10-P-2100F
  SBC control unit, location/task/function Model 211, 230: Request for increased idle speed GF42.46-P-4500SL