Mercedes-Benz ML320. Manual — part 384

Fig. 11: Identifying ME-SFI Ignition System Signal Assignment - Signal Assignment Engine 112

ME-SFI IGNITION SYSTEM SINGLE ASSIGNMENT - GF15.12-P-0001-02B

Fig. 12: Identifying ME-SFI Ignition System Signal Assignment - Signal Assignment Engine 113

TNA rpm signal on ME2.8 with 3 pulses for each engine revolution

ME-SFI IGNITION SYSTEM FUNCTION - GF15.12-P-0001F

ENGINE 104.941 /943 /944 /991 /994 as of 1.8.96

2001 Mercedes-Benz ML320

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

me

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 /95

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

ENGINE 119.980 /981 /982 /985

ENGINE 120.982/983

ENGINE 137.970

2001 Mercedes-Benz ML320

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

me

Fig. 13: Identifying ME-SFI Ignition System Components

Signal assignment

2001 Mercedes-Benz ML320

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

me

Fig. 14: Identifying Signal Assignment - Shown On Engine 119

Function

When the crankshaft is rotating, an alternating voltage is generated in the crankshaft position sensor by the teeth
of the driven plate. In this case, each tooth generates an alternating voltage signal. No voltage is generated
through the gap of 2 missing teeth. The ME-SFI control unit detects the TDC position of the crankshaft with the
2nd negative slope after the gap.

If the signal from the camshaft Hall sensor is at 0 V ("low") at this moment, the ME control unit processes this
in order to detect ignition TDC. This, is used for actuating the ignition coils and the fuel injectors. The high
voltage is distributed rotorlessly. Advantages of the rotorless high voltage distribution are:



significantly reduced electromagnetic interference level (no naked sparks)



no rotating parts



reduction in noise



reduced high voltage connections.

1. Determine ignition angle according to input signals, actuate ignition coils and release ignition

spark.

The ME-SFI control unit essentially analyzes the following signals for determining the ignition angle:

Engine

Recognition of TDC position of
cylinder

Ignition TDC

111

1 and 4

Cylinder 1

104, 112, 113, 119

1 and 6

Cylinder 1

120, 137

Right hand cylinder bank: 1 and 6

Cylinder 1

Left cylinder bank: 7 and 12

Cylinder 7

2001 Mercedes-Benz ML320

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

me