1997 MERCEDES-BENZ ML430 ignition

Fig. 10: Identifying ME-SFI Ignition System Components - Engine 113
ME-SFI IGNITION SYSTEM SIGNAL ASSIGNMENT - GF15.12-P-0001-02A

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 12 © 2006 Mitchell Repair Information Company, LLC.

Fig. 11: Identifying ME-SFI Ignition System Signal Assignment - Signal Assignment Engine 112
ME-SFI IGNITION SYSTEM SING LE 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
Saturday, October 02, 2010 3:18:54 PMPage 13 © 2006 Mitchell Repair Information Company, LLC.

Fig. 13: Identifying ME-SFI Ignition System Components
Signal assignment

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
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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:
EngineRecognition of TDC position of
cylinderIgnition TDC
1111 and 4Cylinder 1
104, 112, 113, 1191 and 6Cylinder 1
120, 137Right hand cylinder bank: 1 and 6Cylinder 1
Left cylinder bank: 7 and 12Cylinder 7

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
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Saturday, October 02, 2010 3:18:54 PMPage 16 © 2006 Mitchell Repair Information Company, LLC.

Engine load
Crankshaft position sensor
Camshaft Hall sensor
Coolant temperature sensor
Intake air temperature sensor/charge air.
Coil ignition: The ME control unit interrupts at the point of ignition timing at the ground end the ignition
coil primary circuit of the ignition coil.
ECI ignition system (engine 137): The ME control unit actuates the output stages in the ECI ignition
modules.

The ignition angle can only be checked with the HHT/STAR DIAGNOSIS.
2.Ignition angle adaptation
2.1 Catalytic converter heating-up (warming-up)
The ignition angle is continuously retarded for about 20 seconds in order to more rapidly warm up the catalytic
converter to its operating temperature if:
coolant temperature at start > 15 °C and < 40 °C
Selector lever position P or N
At the same time idle speed is increased by the idle speed control.
2.2 Idle speed
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.
Altering the ignition angle provides a more rapid control than altering the position of the throttle valve (idle
speed control).
2.3 Deceleration fuel shutoff
The ignition angle is briefly retarded when combustion is resumed (fuel injectors actuated) in order to prevent a
sudden increase in torque.
2.4 Intake air temperature/coolant temperature
The ignition angle is retarded under load, as a function of the intake air temperature and coolant temperature, in
order to prevent an
y knocking tendency at high intake air and coolant temperatures. The ignition angle is

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 17 © 2006 Mitchell Repair Information Company, LLC.

"Retarded" if:
Intake air temperature > 35 °C
Coolant temperature > 105 °C
In supercharged engines the charge air temperature is used as information for the ignition timing adjustment in
place of the intake air temperature.

The values of the retardation of the ignition angle of intake air temperature and coolant temperature are added
together.
2.5 Transmission overload protection
In order to protect the shift elements of the automatic transmission during power shifts (1-2-1, 2-3-2) from
excessive thermal stresses, the ignition angle is briefly retarded during the gearshift and the engine torque
reduced as a result. The ME-SFI control units are supplied with a signal for this purpose from the ETC control
unit (N15/3) over the CAN databus.
2.6 ESP/ASR control mode
In order to reduce the engine torque as rapidly as possible in the ESP/ ASR control mode, the ignition angle is
retarded by the throttle valve actuator (opening angle reduced) prior to the control mode being activated. The
information from the ESP/ASR control unit is supplied over the CAN databus to the ME-SFI control unit.
2.7 Anti-knock control (AKC)
If uncontrolled combustion (knocking) occurs at one or several cylinders, the ignition angle at the relevant
cylinder or cylinders is "Retarded".
2.8 Smooth engine running analysis
To restrain the three way catalytic converter from thermal overload through combustion misfiring and in order
to keep the exhaust emission values, the smooth operation of the engine is continuously monitored.
If combustion misfiring is identified at one or several cylinders, the corresponding fuel injection valves are no
longer actuated after a certain number of misfires.
Engine 104, 111, 112, 113, 119, 120: Smooth operation evaluation is performed through the signals of the
crankshaft position sensor.
Engine 137: Identification of combustion misfiring by means of ionic current signal, see ECI ignition system
function.
2.9 Double ignition engine 112,113,137

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
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Two spark plugs for each cylinder are beneficial because of the arrangement of the valves for achieving optimal
emission levels and smooth engine running.
Each spark plug is actuated separately by the ME-SFI control unit through its own ignition coil. On engine 112,
113 both ignition coils of a cylinder are combined to form a dual ignition coil.
In the lower part load range up to approx. 2000 rpm both ignition sparks of a cylinder are triggered
simultaneously. At moderate and high engine loads, the ignition sparks are triggered offset by as much as 10°
crank angle. In this case, the sequence of actuation is constantly varied in order to achieve a uniform wear of
both spark plugs and to avoid deposits on only one side of the combustion chamber.

For troubleshooting in the dual ignition system, it is possible to switch off one ignition circuit each with HHT or
STAR DIAGNOSIS.
ME-SFI ignition system function
diagramEngine 104GF15.12-P-0001-01D
Engine 111GF15.12-P-0001-01G
Engine 112GF15.12-P-0001-01A
Engine 113GF15.12-P-0001-01B
Engine 119GF15.12-P-0001-01E
Engine 120GF15.12-P-0001-01F
ME-SFI control unit
position/task/design/ function GF07.61-P-5000F
ECI ignition system functionEngine 137GF15.15-P-3000L
Ignition coils,
location/task/design/functionEngine 119, 120GF15.10-P-3102F
Engine 104, 111GF15.10-P-3102G
Engine 112, 113GF15.10-P-3102A
Crankshaft position sensor,
location/task/ design/function GF07.04-P-4116F
Camshaft Hall sensor,
location/task/design/ function GF07.04-P-4117F
Spark plugs,
location/task/design/function GF15.10-P-3101F
Intake air temperature sensor,
location/task/ design/function GF07.04-P-2100F
Hot film mass air flow sensor,
location/task/ design/functionEngine 119, 120 (round
connector)GF07.07-P-4118E
Engine 104, 111, 112,
113, 137GF07.07-P-4118G
Coolant temperature sensor,
location/task/ design/functionEngine 104, 111GF07.04-P-5026G
Engine 112, 113, 137GF07.04-P-5026A
Engine 119, 120GF07.04-P-5026F
Electronic accelerator, Engine 104, 111, 112, GF30.20-P-3010E

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 19 © 2006 Mitchell Repair Information Company, LLC.

location/design/function113, 119, 137
Engine 120GF30.20-P-3010F
Anti-knock control function GF15.12-P-4024F
Transmission overload protection
functionwith automatic
transmissionGF07.61-P-4026F
Overheating/pinging protection
function GF07.61-P-4027F
Intake air temperature correction
function GF07.61-P-4028F
ME-SFI synchronizing fuel
injection and firing order function GF07.61-P-4009F
ME-SFI ignition system signal
assignmentEngine 104GF15.12-P-0001-02D
Engine 111GF15.12-P-0001-02G
Engine 112GF15.12-P-0001-02A
Engine 113GF15.12-P-0001-02B
Engine 119GF15.12-P-0001-02E
Engine 120GF15.12-P-0001-02F
Engine 137GF15.12-P-0001-02L
ME engine speed signal function GF07.61-P-3017F
ASR V control unit
location/task/design/functionwith code 471a
Model 129, 140, 202 as
of 6/94, 170, 208, 210GF42.40-P-4500A
ESP control unit location / task /
functionwith code 472a
Model 129 with engines
104, 119, 120
Model 140
Model 210 with engine
119GF42.45-P-4500A
with code 472a
Model 129 with engine
112, 113
Model 163 up to 8/02,
168, 215
Model 220 (except
220.08/18)
Model 202, 208 with
engine 112, 113
Model 210 with engine
111, 112, 113GF42.45-P-4500B
with code 472a
Model 170 with engines
111, 112
Model 202, 208 with
Engine 111
Model 203GF42.45-P-4500C

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 20 © 2006 Mitchell Repair Information Company, LLC.