Defender M52 ETM

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General Communication About: ETM ZA-VS SL 029 2000 Date: 31 July 2000 PAGE 1 OF 3 Please Initial and Route to the following for information before filing x Dealer Principal x Foreman x Service Personnel - Initial Below x Service Manager x Service Admin. x Service Consultant x Parts Manager x Service Advisor Sales Manager E-Mail: [email protected] Fax: +27 12 522 2284 Technical Bulletins are available on BMW Intranet at URL: http://bmwza01.w9/vk2 Subject: Defender M52 ETM (Electric Trouble Shooting Manual) Model: Pre MY99 and MY99 Vehicles. Complaint: Various dealers requested an after market ETM for the BMW engine Defender, as only engineering drawings were available. Solution: An ETM was drafted by the Technical dept. as a fix to the complaint. The two ETM’s are circuit diagrams related to pre–and-MY99 vehicles. Included below is a basic explanation of what each components function is and how it fits into the system. System DME: The Digital Motor Electronics or MS41.0 as referred to in BMW Explanation: is the electronic heart of the engine. It uses various sensors as inputs to determine the optimum ignition and injection to the engine. DME Relay: It supplies all the sensors and actuators fitted to the engine with battery voltage. When the ignition is switched off the DME first goes through a shutdown procedure before switching off the DME relay. Inertia switch: When the vehicle is involved in an accident the inertia switch switches off the fuel pump relay on the pre MY99 vehicles and the DME relay on the MY99 vehicles. That will stop the engine from running and being a fire hazard. In some isolated cases it may be triggered by “heavy” off road riding as well. Battery voltage: The DME uses this voltage to adapt the sensors and actuators to the changing battery voltage for optimum performance. Ignition switch: It supplies the primary side of the coils and the DME with ignition voltage. As soon as the DME receives this signal it does a self-test, which takes a few milli seconds and gets ready to start the engine. Intake air temperature sensor: It measures the air temperature of the air entering the engine and in conjunction with the air mass meter informs the DME of the air mass entering the engine. The DME will than be able to control the fuel injection quantity to each injector.

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Defender BMW 2.8i M52 electrical manual

Transcript of Defender M52 ETM

  • General Com m un icat ion About: ETM ZA-VS SL 029 2000 Date: 31 July 2000 PAGE 1 OF 3

    Please Initial and Route to the following for information before filing x Dealer Principal x Foreman x Service Personnel - Initial Below x Service Manager x Service Admin. x Service Consultant x Parts Manager x Service Advisor Sales Manager

    E-Mail: [email protected] Fax: +27 12 522 2284

    Technical Bulletins are available on BMW Intranet at URL: http:/ /bmwza01.w9/vk2

    Subject: Defender M52 ETM (Electric Trouble Shooting Manual)

    Model: Pre MY99 and MY99 Vehic les. Complaint: Various dealers requested an after market ETM for the BMW engine

    Defender, as only engineering drawings were available. Solution: An ETM was drafted by the Technical dept. as a fix to the complaint. The two ETMs are circuit diagrams related to preand-MY99 vehicles.

    Included below is a basic explanation of what each components function is and how it fits into the system.

    System DME: The Digital Motor Electronics or MS41.0 as referred to in BMW Explanation: is the electronic heart of the engine. It uses various sensors as inputs to

    determine the optimum ignition and injection to the engine.

    DME Relay: It supplies all the sensors and actuators fitted to the engine with battery voltage. When the ignition is switched off the DME first

    goes through a shutdown procedure before switching off the DME relay. Inertia switch: When the vehic le is involved in an accident the inertia switch

    switches off the fuel pump relay on the pre MY99 vehicles and the DME relay on the MY99 vehicles. That will stop the engine from running and being a fire hazard. In some isolated cases it may be triggered by heavy off road riding as well.

    Battery voltage: The DME uses this voltage to adapt the sensors and

    actuators to the changing battery voltage for optimum performance. Ignition switch: It supplies the primary side of the coils and the DME with

    ignition voltage. As soon as the DME receives this signal it does a self-test, which takes a few milli seconds and gets ready to start the engine.

    Intake air temperature sensor: It measures the air temperature of the air

    entering the engine and in conjunction with the air mass meter informs the DME of the air mass entering the engine. The DME will than be able to control the fuel injection quantity to each injector.

  • About: ETM ZA VS SL 029 2000 MIDRAND ZA-VS-2 PAGE 2 OF 3 July 2000

    E-Mail: [email protected] Fax: +27 12 522 2284

    Technical Bulletin Documents are available on BMW Intranet

    Coolant sensor (X6256): This NTC sensor informs the DME and not the instrument cluster of the coolant temperature. The DME uses this information for cold starting purposes. (Enriches the air/ fuel mixture during cold starts to aid starting)

    Idle actuator: Like the name suggests it control the idling by varying the

    amount of air bypassing the c losed throttle flap. It can adapt to various loads on the engine. Itll for example increase the idling when the A/C compressor is switched on.

    Fuel injectors: They atomise a calculated amount of fuel into the intake

    system for combustion. They will be switched off if their relevant coil has a firing fault. That is done for emission reasons, as the fuel wont burn and might damaged the catalytic converters, which in this case is not fitted to Defenders.

    Ignition coils: They convert the 12V of the battery to a few thousand volts,

    which used to ignite the atomised air/ fuel mixture. Each coils secondary voltage is monitored by pin 56 of the DME. The DME recognises what cylinder is firing by looking at the crankshaft-and-camshaft sensor. When it does not receive the secondary voltage signal at the correct time it knows that something is wrong with that specific coil and cuts it and its relevant injector out.

    Fuel pump relay: It is activated by pin 69 of the DME, which is activated by

    the DME relay, and will switch off if the vehicle is involved in an accident. Tank vent valve: Only on MY99 vehicles. Only the harness is fitted to these

    vehicles. This valve is used in conjunction with a charcoal canister connected to the tank. When it opens it allows fuel vapour from the tank through the charcoal canister through the valve to be vented into intake manifold for emission reasons.

    Oxygen sensors: Not fitted on the Defender. It is used to measure the

    exhaust gases for feedback to the DME to enrich or lean out the mixture. Its done for emission reasons.

    Hot film Air mass meter: It measures the air of the air entering the engine

    and in conjunction with the intake air temperature sensor informs the DME of the air mass entering the engine. The DME will than be able to accurately control the fuel injection quantity to each injector.

    Vanos valve: it is used to hydraulically vary the inlet camshaft timing. That

    results in smoother lower rpm idling and a flatter torque curve. Throttle potentiometer: It is used by the DME to recognise the load on the

    engine and it is also used for overrun situations. In other words if the throttle is c losed and the engine is still rotating at 4000 rpm the DME knows that the wheels are driving the engine. This situation is called over run.

    240 ohm 2W resistor: That is the path that the coils will follow to

  • About: ETM ZA VS SL 029 2000 MIDRAND ZA-VS-2 PAGE 3 OF 3 July 2000

    E-Mail: [email protected] Fax: +27 12 522 2284

    Technical Bulletin Documents are available on BMW Intranet

    ground. The .5 B wire is only used to see if the relevant coil has sparked. Refer to ignition coils. Knock sensors: They measure combustion and will inform the DME if a specific cylinder is pre-igniting or knocking (pinging). The DME will than retard that specific cylinders timing by a certain amount and than advance it again in steps to the programmed value. Camshaft sensor: It is used as a feedback to the DME to inform it how much the Vanos has moved the inlet camshaft. This sensor is used in conjunction with the crankshaft sensor to determine the cylinder recognition and rpm. Its also the backup to the crankshaft sensor. For this reason, unlike most other engine management systems the M52 can be started without the crankshaft sensor. Alternator: The pre MY99 D+ signal has got a diode inline to the Instrument cluster. Oil pressure: Switches off the warning light in the cluster if the engine pressure reaches a certain limit. Temperature sensor: Although it is housed in the same unit as the DME temperature sensor housing its dedicated to the instrument c luster. Engine speed: Derived from the crankshaft sensor and used to drive revcounter gauge.

    Road speed: Derived from the speed sensor on the transfer box and sent to instrument cluster for the Speedo. From there the signal gets filtered and supplied to the DME for top speed limiting. If this signal is missing the DME will only rev up to a specific RPM level and in doing so will stop the vehicle from reaching its top speed.

    Pierre Dieperink Jan Ltter Technical Consultant Product Support Manager

  • Defender M52 ETM(Electric Trouble Shooting Manual)Pre-99 MY99 MY onwards