m54 engine - BMWClub.lv

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SECONDARY AIR INJECTIONThis ECM controlled function remains unchanged fromthe previous Siemens MS system, however there is ahardware change.The Air Injection Inlet Valve mounts directly to the cylinderhead, with a passageway machined through thehead. This eliminates the external Air Injection manifolddistribution pipes to the exhaust manifolds.SECONDARY AIR INJECTION MONITORINGIn order to reduce HC and CO emissions while the engine is warming up, BMW implementedthe use of a Secondary Air Injection System in. Immediately following a cold enginestart (-10 - 40°C) fresh air/oxygen is injected directly into the exhaust manifold. By injectingoxygen into the exhaust manifold:• The warm up time of the catalyst is reduced• Oxidation of the hydrocarbons is acceleratedThe activation period of the air pump can vary depending on engine type and operatingconditions.Conditions for Secondary Air Pump Activation:REQUIREMENTSSTATUS/CONDITIONM52 MS 43.0 & M44STATUS/CONDITIONM73Oxygen sensor Open Loop Open LoopOxygen sensor heating Active ActiveEngine coolant temperature -10 to 40ºC* -10 to 40ºC* StageEngine bad Predefined Range Predefined RangeEngine speed Predefined Range Predefined RangeFault CodesNo Secondary Air Faults“currently present”No Secondary Air Faults“currently present”*NOTE: Below -10°C the air injection pump is activated only as a preventive measure toblow out any accumulated water vapor that could freeze in the system.38M54engMS43/ST039/3/17/00
The Secondary Air Injection System is monitored via the use of the pre-catalyst oxygen sensor(s).Once the air pump is active and is air injected into the system the signal at the oxygensensor will reflect a lean condition. If the oxygen sensor signal does not change withina predefined time a fault will be set and identify the faulty bank(s). If after completing thenext cold start and a fault is again present the "Service Engine Soon" light will be illuminated.Example: Secondary Air Injection Monitoring (M54-Siemens System)During a cold start condition air is immediately injected into the exhaust manifold and sincethe oxygen sensors are in open loop at this time the voltage at the pre catalyst sensor willreflect a lean condition) and will remain at this level while the air pump is in operation. Oncethe pump is deactivated the voltage will change to a rich condition until the system goesinto closed loop operation.M54 System Operation:The pump draws air through its own air filter and delivers it to both exhaust manifoldsthrough a non-return (shutoff valve). The non-return valve is used to:1. Control air injection into the exhaust manifold - A vacuum controlled valve will open thepassageway for air to be injected once a vacuum is applied.2. Prevent possible backfires from traveling up the pipes and damaging the air pump whenno vacuum is applied.The control module activates the vacuum vent valve whenever the air pump is energized.Once the vacuum vent valve is energized a vacuum is applied to the non-return valve whichallows air to be injected into the exhaust manifold. A vacuum is retained in the lines, by theuse of a check valve, in order to allow the non-return valve to be immediately activated oncold engine start up. When the vacuum/vent valve is not energized, the vacuum to thenon-return valve is removed and is vented to atmosphere.39T:/Automobiles/ST039/handouts
Page 1: Table of ContentsSubjectPageM54 Eng
Page 4 and 5: M54 ENGINEMechanical ChangesIn addi
Page 6 and 7: M54B30 ENGINE293225ART-HPCHARTB30.6
Page 8 and 9: REVIEW QUESTIONS1. What is the majo
Page 10 and 11: SYSTEM OVERVIEW I-P-OServiceEngineS
Page 12 and 13: MS 43 NEW FUNCTIONSACCELERATOR PEDA
Page 14 and 15: MS 43 NEW FUNCTIONSEDK THROTTLE POS
Page 16 and 17: MS 43 NEW FUNCTIONSMAIN RELAY MONIT
Page 18 and 19: MS 43 NEW FUNCTIONSDM-TL (DIAGNOSIS
Page 20 and 21: DM-TL (DIAGNOSIS MODULE - TANK LEAK
Page 22 and 23: LEAK DIAGNOSIS TESTPHASE 1 - REFERE
Page 24 and 25: TEST RESULTSThe time duration varie
Page 26 and 27: OXYGEN SENSOR SIGNAL INFLUENCE ON I
Page 28 and 29: CRANKSHAFT SENSORThe crankshaft sen
Page 30 and 31: EMISSIONS RELEVANT:During an interv
Page 32 and 33: MASS AIR FLOW SENSOR HFMThe Siemens
Page 34 and 35: NOTE: With extremely hot oil temper
Page 36 and 37: The dual VANOS in conjunction with
Page 40 and 41: ENGINE/VEHICLE SPEEDLIMITATIONFor e
Page 42 and 43: RESONANCE/TURBULENCE INTAKE SYSTEMO
Page 44 and 45: #1 Cylinder Intake Valve openLow to
Page 46 and 47: IDLE SPEED CONTROLThe ECM determine
Page 48 and 49: PURGE VALVEThe purge valve (TEV) is

m54 engine - BMWClub.lv

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