Mercedes-Benz ML320. Service manual - part 385

 

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Mercedes-Benz ML320. Service manual - part 385

 

 

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 any 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 

 

"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

  

me 

 

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 
diagram

Engine 104

GF15.12-P-0001-01D

Engine 111

GF15.12-P-0001-01G

Engine 112

GF15.12-P-0001-01A

Engine 113

GF15.12-P-0001-01B

Engine 119

GF15.12-P-0001-01E

Engine 120

GF15.12-P-0001-01F

 

ME-SFI control unit 
position/task/design/ function

 

GF07.61-P-5000F 

 

ECI ignition system function

Engine 137

GF15.15-P-3000L

 

Ignition coils, 
location/task/design/function

Engine 119, 120

GF15.10-P-3102F

Engine 104, 111

GF15.10-P-3102G

Engine 112, 113

GF15.10-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/function

Engine 119, 120 (round 
connector)

GF07.07-P-4118E

Engine 104, 111, 112, 
113, 137

GF07.07-P-4118G 

 

Coolant temperature sensor, 
location/task/ design/function

Engine 104, 111

GF07.04-P-5026G

Engine 112, 113, 137

GF07.04-P-5026A 

Engine 119, 120

GF07.04-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 

 

location/design/function

113, 119, 137

 

 

Engine 120

GF30.20-P-3010F

 

Anti-knock control function

 

GF15.12-P-4024F

 

Transmission overload protection 
function

with automatic 
transmission

GF07.61-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 
assignment

Engine 104

GF15.12-P-0001-02D

Engine 111

GF15.12-P-0001-02G

Engine 112

GF15.12-P-0001-02A

Engine 113

GF15.12-P-0001-02B

Engine 119

GF15.12-P-0001-02E

Engine 120

GF15.12-P-0001-02F

Engine 137

GF15.12-P-0001-02L

 

ME engine speed signal function

 

GF07.61-P-3017F 

 

ASR V control unit 
location/task/design/function

with code 471a 
Model 129, 140, 202 as 
of 6/94, 170, 208, 210

GF42.40-P-4500A

 

ESP control unit location / task / 
function

with code 472a 
Model 129 with engines 
104, 119, 120 
Model 140 
Model 210 with engine 
119

GF42.45-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, 113

GF42.45-P-4500B 

with code 472a 
Model 170 with engines 
111, 112 
Model 202, 208 with 
Engine 111 
Model 203

GF42.45-P-4500C

 

2001 Mercedes-Benz ML320 

1998-2005 ENGINE Electrical System - Engine - 163 Chassis

  

me 

 

 

 

 

 

 

 

 

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