Component description for the ME-SFI [ME] control unit - GF07.61-P-6000BK
ENGINE 113.967 in MODEL 219
ENGINE 113.964 in MODEL 164.1
ENGINE 113.971 in MODEL 251
Shows model 219
Location
- Model 219 In the driver-side SAM control unit with fuse and relay module
- Models 164.1, 251 at the front in the front passenger footwell under the floor panel.
Design
The aluminum ME control unit is designed as a shell concept standard housing. It is designed for installation in a protective housing. The cables are connected by means of 5 couplings.
1, 2, 3 Engine plug connections
Control of fuel injection system
The fuel injectors are actuated individually, in line with the firing order (sequentially), on the basis of the input signals and the maps stored in the ME-SFI control unit. The ME-SFI control unit calculates the opening times (injection times) of the fuel injection valves.
Control of ignition system
The ME control unit actuates the ignition coils in line with the input signals and the maps stored in the ME control unit. In addition, it also calculates ignition angle values and regulates the antiknock control (AKR).
Control of idle speed control
The ME control unit actuates the throttle valve actuator in line with the input signals and the performance maps stored in the ME control unit.
4, 5 Vehicle plug connections (design)
Control of cruise control
The ME control unit actuates the throttle valve actuator for the cruise control function on the basis of the input signals and the position of the cruise control pushbutton switch.
Additional Cruise control functions are a variable speed limit (except
) and Distronic (SA).
Drive authorization system/immobilizer
The ME-SFI control unit is always equipped with an immobilizer. When the vehicle is locked, the EIS control unit transmits information via the CAN data bus to the ME control unit, which then locks the engine control (blocks).
The engine can be started (start enable) only once the vehicle is again unlocked with the authorized key and the EIS control unit transmits a message to this effect over the CAN data bus to the ME control unit.
Engine speed signal
The ME control unit generates the short circuit-proof engine speed signal TNA from the signals supplied by the crankshaft position sensor and transmits it to other control units as follows:
- Square-wave signal with constant on/off ratio
- maximum current approx. 20 mA
- Pulses/crankshaft revolution
Fuel consumption signal
The consumption signal is calculated from the injection times (e.g. 8 liters/hour) and is transmitted via CAN to the trip computer in the instrument cluster.
Version coding
is used for adapting the ME control unit to different vehicle versions and vehicle equipment by means of matching code numbers. The coding should be performed with STAR DIAGNOSIS. The following vehicle versions or equipment versions can be coded using the variant coding:
- Vehicle model
- National version
Computer run-on
After switching off the ignition, the ME control unit carries out a computer delayed-off running, in which certain data memory (e. g. diagnostic trouble code memory) is updated. The duration is dependent on the coolant temperature (at 80°C approximately 4 seconds and at -30°C approximately 150 seconds). If the ignition is switched off without starting the engine, the run-on time is always approx. 4 s.
Correction programming
Different performance maps for the engine control can be activated with the correction programming function in the ME control unit. The programming can be carried out with STAR Diagnosis when ignition is "ON", via the data link connector.
The following maps can be influenced:
- Ignition maps for adapting to different fuel quality (except
)
- Mixture maps for enriching the air/fuel mixture in different operating states (except
- Idling speed
- Sensitivity to the smooth running analysis
- Temperature correction for switching electrical suction fan on and off.
Diagnosis/DTC memory
The ME control unit checks its input and output signals for plausibility and recognizes possible faults. The following faults can be distinguished:
- Faults which are permanently present.
- Loose contact faults which occur while driving.
The faults can only be read out in the ME control unit and erased with the STAR DIAGNOSIS.
Individual functions can be actuated specifically for diagnostic purposes. These are listed in the menu items.
Various engine operating information is transmitted via the CAN data bus by the ME control unit to other control units that are connected to the CAN data bus.
Start recognition
The engine control unit is informed about the introduced starting procedure via the CAN message "circuit 50". This is necessary in order, for example, to trigger the start quantity control, the starter control, the post-start enrichment and the ignition timing when starting.