Performance Controls

Performance Controls







Sport Switch




The MS S54 ECM contains two different throttle progression program curves (Sport and Normal). The sport program is selected by pressing the Sport switch located in the center console switch panel.

The switch provides a ground signal (input) to the ECM when pressed. The MS S54 activates the sport characteristics for the EDR throttle control. This provides an increase in throttle opening and response time over the non-sport position.

Power Transmission Switch







The power transmission switch (circuit) consists of two switches in series. The circuit includes a clutch switch and a gear selector switch on the transmission. The functions of the power transmission switch are as follows:
- Cutout for cruise control operation
- Enable condition for idle control

The switches provide a high signal for the MS S54 when the clutch is disengaged and the transmission is in gear. If either the clutch is engaged or the transmission is in neutral, the cruise control will be disengaged.

Cruise Control: As with other electronic throttle systems, the MS S54 ECM takes over the function of cruise control. Throttle activation is provided by the MS S54 electronic control of the EDR Actuator and monitoring of the feed-back potentiometers.




All driver requested cruise control function requests are provided to the MS S54 from the MFL II control module in the steering wheel over a single FGR data lead.

Oil Temperature/Level Sensor




The electronic level sensor is located in the engine sump mounted to the engine oil pan. The probe of the level sensor contains two temperature sensing elements.
- One senses the engine oil temperature.
- The other is heated to 10 °C above the temperature of the engine and then is allowed to cool.

The length of time it takes to cool the heated element is how the sensor determines the engine oil level. When the oil level is high it covers a larger portion of the probe submersed in the oil sump. The engine oil around the probe absorbs the heat of the heated element quicker than if the level is low.

The microprocessor in the base of the sensor produces a pulse width modulated signal proportional to the oil level. The pulse width increases with a decreased level of oil.

Based on the oil temperature, the visual warning LEDs in the tachometer will illuminate at cold engine start up and slowly be extinguished as the oil temperature increases. One amber and the red LEDs always stay illuminated reminding the driver of maximum rpm zone.

The oil temp sensor also serves as a vital input for VANOS operation, varying the solenoid control based on oil temperature (reaction time of camshaft movement). In the event of a fault the engine coolant temperature is used as a substitute value.

Electric Cooling Fan: The electric cooling fan is controlled by the ECM. The ECM uses a remote power output final stage (mounted on the fan housing). The power output stage receives power from a 50 amp fuse. The electric fan is controlled by a pulse width modulated signal from the ECM.




The fan is activated based on the ECM calculation of:
- Coolant outlet temperature (monitored by the Radiator Outlet Temperature Sensor)
- Calculated (by the ECM) catalyst temperature
- Vehicle speed
- Battery voltage
- Air Conditioning refrigerant pressure (calculated by IHKA and sent via the K-Bus to the ECM)

Workshop Hints


IMPORTANT!
From December 2001 production, M3 and M roadster/coupe vehicles with S54 engines are delivered to the centers with the engine speed electronically limited to 5500 rpm as a transportation protection feature.


During the pre-delivery inspection the engine speed limiter function has to be disabled using DISplus or MoDIC loaded with CD28.0 or higher. Refer to SI 12 01 02 for additional details.

Procedure
- Perform a "short test" on the ECM (DME) only
- Select "Control Units Functions" path
- Select "Digital Motor Electronics DME"
- Select "Acknowledge Handover Inspection"
- Select "Activate"
- The display will show "off: terminate"

Tools and Equipment




The DISplus/MoDIC as well as a reputable hand held multimeter can be used when testing inputs/components.

It is best to make the checks at the ECM connection, this method includes testing the wiring harness.




The correct Universal Adapter for the MS S54 application should be used (#90 88 6 121 300). This will ensure the pin connectors and the harness will not be damaged.




When installing the Universal Adapter to the ECM (located in the Electronics Box in the engine compartment), make sure the ignition is switched off.