Zenith Electronic Engine Management System
zzzEMSZEEMSZEEMSZenith Electronic Engine Management SystemPropane and GasolineElectronic Fuel InjectionSlide 1
ZEEMSHomePagezzzEMS ZEEMS System Advantages Block Diagram ECU, Electronic Control Unit Inputs Output Controls System Operation Diagnostics No Start Diagnostics SpecificationsSlide 2
ZEEMSzzzEMSThe ZEEMS AdvantagesPrecise fuel controlthroughout all operating temperatures and conditionsPrecise ignition timing controlthroughout all operating temperatures and conditionsVirtually eliminates “flat spots” and engine run-on (dieseling)Achieves maximum power with lowest emissionsSlide 3
ZEEMSzzzEMSThe ZEEMS Control system electricallycontrols the following:Fuel Delivery via fuel injector (gas, propane or both)Engine RPM via throttle shaft actuator controlSpeed-Density DiscussionSlide 4
zzzEMSZEEMSThe ZEEMS SystemThe ZEEMS system is a“Speed-Density” design.This system measures the engine RPM(speed of the engine)and calculates theDensity of the Air(from atmospheric pressure and temperature of the air)to determine the optimum fuel and air settings forthe altitude and climatic conditions.Slide 5
zzzEMSZEEMSZEEMS Block DiagramElectrical fuel shut off/on, propane (LPG)Electric fuel pump, gasolineInput SensorsRPMFuel Return,gasoline onlyDistributorThrottle ActuatorFuel Tank,propaneorgasolineECUElectronicControlUnitFuel InjectorSlide 6
ZEEMSzzzEMSZEEMS COMPONENT .18.THROTTLE BODYECUINJECTOR02 SENSORIATECTMAPTB COOLANT FITTINGSSPARK PORT VACUUM ADVANCEFUEL PUMPFUEL FILTERPRIMARY VAPORIZERSECONDARY REGULATORMANIFOLD ADAPTERHEAT SHIELDLP FILTERFUEL INLETGASOLINE PRESSURE REGULATORSlide 7
zzzEMSZEEMSThe ECU is the ‘control center’ of the ZEEMS,sometimes called the processor or “brain box”(logic device)The ECU monitors theinput sensors,compares toprogrammed“look up tables”and then controls theoutput devices.ECUElectronicControlUnitSlide 8
zzzEMSZEEMSThe White Connectoris used for high currentloads, such as batterypower and ground andcontrolling the out putdevices.The Black Connectoris used for low levelcurrent devices, such asinput signals, transmitand receive signals, andother low voltagesignals.ECUElectronicControlUnitBattery Ground FeedPins 20 & 21 onWhite ConnectorBattery Power FeedPins 22 & 23 onWhite ConnectorSlide 9
zzzEMSZEEMSThe ECU monitorsmost input sensorsonce every distributorpulse or engine“event”, depending onengine RPM andoperating conditions.One engine “event” isan ignition pulse(spark plug firing).ECUElectronicControlUnitThere aretwo distributor pulses(events)per engine revolutionon a 4 cylinder, 4 cycleengineTherefore:500 RPM 1000 events1000 RPM 2000 events2000 RPM 4000 eventsSlide 10
zzzEMSZEEMSThe ZEEMS systems uses several input devicesto monitor the engine and atmospheric conditions.ECU InputsEngine RPMEngine CoolantTemperature (ECT)Intake AirTemperature (IAT)Manifold AbsolutePressure (MAP)Exhaust Gas OxygenSensor (EGO)ECUElectronicControlUnitLets examineeach inputsensor in depth(if equipped)Slide 11
zzzEMSZEEMSRPMECU InputsEngine RPMEngine RPMECUElectronicControlUnitEngine RPM is determinedfrom the distributor pulsesgenerated by the magneticpick up and converted to adigital pattern.Slide 12
zzzEMSZEEMSRPMECU InputsEngine RPMEngine RPMECUElectronicControlUnitFor every ignition pulse, asignal is received at theECU.The ECU then signals fuelinjector to “turn on” andspray fuel.One fuel injector pulse per“event”.Slide 13
zzzEMSZEEMSECT & IATEngine Coolant Temp Sensor (ECT) , Intake Air Temp Sensor (IAT)ECU InputsECTECUIATElectronicControlUnitThe ECT is located inManifold Adapter under theThrottle Body or in enginehead (coolant stream).The IAT is located in theThrottle Body assembly.Both sensors are two (2)wire sensors.Slide 14
zzzEMSZEEMSECT & IATEngine Coolant Temp Sensor (ECT) , Intake Air Temp Sensor (IAT)ECU InputsThe ZEEMS system uses aNegative TemperatureCoefficient (NTC) thermistorsfor the ECT and IAT sensors.ECTECUIATElectronicControlUnitA thermistor changes itsinternal resistance as thetemperature changes.A “NTC” thermistor resistanceincreases as the temperaturedecreases, and the resistancedecreases as the temperatureincreases.Slide 15
zzzEMSZEEMSECT & IATEngine Coolant Temp Sensor (ECT) , Intake Air Temp Sensor (IAT)ECU InputsECTIATECUThe ECU “monitors” theECT and IAT wires todetermine the temperaturechanges.ECUmonitors hereSlide 16
zzzEMSZEEMSMAPManifold Absolute Pressure SensorECU InputsThe MAP is located betweenthe throttle body assemblyand the ECU .Manifold AbsolutePressure SensorECUElectronicControlUnitThis MAP sensor is a three(3) wire sensor similar inoperation to a potentiometer.Routing to the intakemanifold source isaccomplished by a passageway drilled from the throttlebore directly into the MAP.Slide 17
zzzEMSZEEMSMAPECU InputsManifold AbsolutePressure SensorECUElectronicControlUnitThe MAP changes itsinternal resistance as theatmospheric or intakemanifold pressure changes.The MAP sensor with theECU calculates thebarometric pressure whenthe key is turned on.(KOEO Key On Engine Off).As the engine starts/runs, theMAP’s internal resistancechanges causing the signalwire voltage to change.(KOER Key On Engine Run).Slide 18
zzzEMSZEEMSMAPECU InputsManifold AbsolutePressure SensorECUElectronicControlUnitThis sensor has twochambers internally. Thesechambers are isolated by asilicone diaphragm.Slide 19
zzzEMSZEEMSMAPECU InputsManifold AbsoluteSensorThe ECU sends afixed 5 vDC /- 10% voltageto the MAP.ECUElectronicControlUnit5 volt DCReference VoltageThe ECU “monitors” thesignal wire to determine thebarometric pressure and/orengine load changes.(intake manifold pressure).ECU monitors hereSlide 20
azzzEMSZEEMSEGOedexpanaononOxygeEGOExhaust GasOxygen Sensor(if equipped)ECU InputsThe EGO is located on theexhaust pipe within six (6)inches of the exhaustmanifold. (15 cm)Exhaust Gas OxygenSensorECUElectronicControlUnitThis sensor is a four (4)wire sensor.The ZEEMS system uses aheated EGO sensor.Slide 21
ickzzzEMSZEEMSEGOhereforEGO(if equipped)ECU InputsExhaust Gas OxygenSensorExhaust GasOxygen SensorThe EGO sensor generatesa DC voltage (0-1vDC) thatis proportional to theOxygen content of theexhaust stream andambient oxygen.adetailedexECUElectronicControlUnitWhen the Oxygen (O2)content in the exhauststream goes up the voltagegoes down.QuestionIf the engine is running withtoo much fuel and nomisfires, will the EGOvoltage be high or low?Slide 22
zzzEMSZEEMSEGOEGO(if equipped)ECU InputsExhaust Gas OxygenSensorECUElectronicControlUnitExhaust GasOxygen SensorWhen the EGO sensorapproaches 600 degrees“F”/ 300 degrees “C” itstarts to operate properly.An internal heater bringsthe EGO to its operatingtemp and maintains thistemp if the exhaust gasestemp decreases.The EGO heater is a 12vheater controlled by theignition switch. This is notcontrolled by the ECU.These are the white wiresgoing to sensor harness.Slide 23
EGOExhaust GasOxygen Sensor(if equipped)ECU InputsEGOHeaterThe EGO generatesvoltages between 0-1vDC.ECUElectronicControlUnitThe ECU “monitors” thesignal wire to determine theO2 content of the exhauststream.Inputs,EGOEGOEGOzzzEMSZEEMSECU monitors hereKey Switch OnSlide 24
zzzEMSZEEMSEGOEGOExhaust GasOxygen Sensor(if equipped)ECU InputsEGOHeaterEGOBias voltage0.440-0.460 vDCECUElectronicControlUnitThe ECU internally sends a‘bias’ voltage to the EGOsignal wire. This ‘bias’voltage is in the0.4 - 0.5 vDC range.If the EGO generates avoltage higher than the biasvoltage the ECU determinesless fuel is required, if underthe bias voltage, more fuel isrequired.ECU monitors hereKey Switch OnSlide 25
zzzEMSZEEMSThe ZEEMS systems uses several input devicesto monitor the engine and atmospheric conditions.ECU InputsEngine RPMEngine CoolantTemperature (ECT)Intake AirTemperature (IAT)Manifold AbsolutePressure (MAP)Exhaust Gas OxygenSensor (EGO)ECUInput SensorReviewElectronicControlUnit(if equipped)Slide 26
zzzEMSZEEMSThe ZEEMS systems uses two output devices.Commands to the outputs are determined from input conditions.ECU OutputsOutput ControlsLets examineeach outputdevice in depthECUElectronicControlUnitGovernor ActuatorFuel InjectorSlide 27
zzzEMSZEEMSGovernorECU OutputsThe Governor is an electricactuator which controls(turns) the throttle plate.The governor actuator motoris the only connection to thethrottle plate.The governor uses twowires to control the actuator.Governor ActuatorECUElectronicControlUnitA ground wire and thecontrol circuit from the ECU.Slide 28
ZEEMSGovernorThe governor is located onthe throttle body assemblyand is the only part that isnot field replaceable.The throttle plate has amechanical stop.The proper RPM for themechanical stop isDependant on theapplication (see spec sheet).ozzzEMS vernorECU OutputsGovernor ActuatorECUElectronicControlUnitSlide 29
ZEEMSGovernorTo control the governor,the ECU uses two inputs: Throttle pedal or speedswitch engine RPMFrom the RPM input(condition), the ECUcommands the governor toincrease or decrease theRPM depending on theengine load and otheroperating conditions tomatch the throttle pedal(speed switch)desired RPM.ozzzEMS vernorECU OutputsGovernor ActuatorECUElectronicControlUnitSlide 30
zzzEMSZEEMSGovernorECU OutputsThe ECU controls the powerside to the Governor withthe ground coming fromECU.SpeedCommandEngine RPMGovernor Actuator CoilECUElectronicControlUnit“High Side”Switch CircuitECU controls hereThis circuit controls the ‘power side’of the Governor Actuator CoilSlide 31
ZEEMSGovernorozzzEMS vernorECU OutputsGovernor Actuator CoilThe duty cycle will varyaccording to the engine load,based on the throttle platesetting, ignition timing, qualityof fuel and many other factors.The duty cycle must change asthe demand for engine RPM iscommanded.ECUElectronicControlUnit“High Side”Switch CircuitECU controls hereSlide 32
zzzEMSZEEMSGovernorIf the ECU or throttlebody/governor assemblyis replaced or the baseidle setting is altered,the ECU must relearnthe base throttle setting.This procedure takes 2minutes during normaloperation.This ‘idle setting relearn’procedureis a ‘self-programming’operation of the ECUECU OutputsGovernorECUElectronicControlUnitSlide 33
zzzEMSZEEMSGovernorECU OutputsGovernorThe proper RPM for themechanical stop isdependant on engine. Thisscrew is air flow set at Zenithand tamperproof.The mechanical stop is requiredonly to eliminate the ThrottlePlate from sticking inside Bore.ECUElectronicControlUnitSlide 34
ZEEMSzzzEMSSelf-Learn ProceduresGovernor Idle Self-LearnEngine Temperature must be at 161 degrees ºF or above.Engine at Idle speed.Procedures:A.For harness with Self-Learn wire and Throttle pedal.1. Using a Jumper wire, ground the Self-Learn wire to frame (ground). Note: keep thiswire grounded during the entire Self-Learn procedure.2. Start engine and Fully Depress the throttle pedal Once Only.3. Allow the engine to idle for a minimum of two (2) full minutes.4. Turn off engine and disconnect the jumper wire from the Self-Learn wire.5. The Self-Learn process is now complete.Notes, Precautions.1.2.3.Do not touch any function during this procedure.When the Self-Learn procedure is in process, the Throttle pedal is disabled.For Dual fuel applications, the Self-Learn procedure must be performed for each fuelselection.Slide 35
zzzEMSZEEMSSelf-Learn ProceduresGovernor Idle Self-LearnEngine Temperature must be at 161 degrees ºF or above.Engine at Idle speed.Procedures:B.For units that are not required to Self-Learn with wire1. Start engine and allow to run at Idle for a minimum of two (2) full minutes.Notes, Precautions.1.2.Do not touch any function during this procedure.For Dual fuel applications, the Self-Learn procedure must be performed for eachfuel selection.Slide 36
zzzEMSZEEMSFuel InjectorThe Fuel Injector is an electricactuator which controls the fuelflow to the engine.The gasoline fuel injector iscalibrated at 10-12 psi(open Loop)14psi(closed Loop)and thepropane fuel injector iscalibrated at 22-24 psi(open Loop)15psi(closed Loop)ECU OutputFuel InjectorECUElectronicControlUnitNormal servicing is required.Dependant on Fuel Quality.Slide 37
zzzEMSZEEMSFuel InjectorECU OutputTo control the fuel injector, theECU provides the power andcontrols the “ground side” of thecircuit.The injector fires once perengine event and varies thepulse width (on-time) accordingto the engine conditions.The engine conditions aremonitored by the input sensorsand the the ECU commandsthe fuel injector with a longer orshorter pulse width (on time).Fuel InjectorECUElectronicControlUnitSlide 38
zzzEMSZEEMSFuel InjectorECU Output12 v DCThe injector “triggers” once forevery distributor referencespulse going into the ECU.Engine RPMFuel InjectorECUElectronicControlUnitECU controls here“Low Side” Switch CircuitSlide 39
zzzEMSZEEMSFuel InjectorECU OutputThe ECU varies the amount ofon-time of the injector bylooking at the various inputsensors of the engine.ECTIATMAPEGOFuel Injector12 v DCECUElectronicControlUnitThe ECU varies theinjector pulse widthOffEngine RPMECU controls here“Low Side”Switch CircuitOnSlide 40
zzzEMSZEEMSIgnitionTimingThe ECU controls theignition timing based on theMAP, ECT, IAT and RPMinputs.Base Ignition Timingchecked with vacuumadvance disconnected atIdle speed.4 degrees BTDC for Lp.12 degrees BTDC forGasoline and Duel FuelECTIATECU OutputIgnition TimingECUElectronicControlUnitMAPEGORPMSlide 41
zzzEMSZEEMSOpen & Closed LoopClosed LoopOpen LoopDuring warm-up the ECUcontrols in “open loop”.The ECU controls theoutputs based on the MAP,ECT, IAT and RPM inputs.Open Loop is defined as“no EGO Slide 42
zzzEMSZEEMSOpen & Closed LoopClosed LoopOpen LoopECUECTIATMAPEGORPMElectronicControlUnitTo achieve ‘closed loop’ theseconditions must be met: engine fully warm EGO hot and operating engine running for 15-120secondsClosed Loop is defined as theEGO is monitoring thethe O2 content of the exhauststream and the ECU isadjusting the fuel injector pulsewidth based on the EGOvalues.Slide 43
zzzEMSZEEMSClosed Loop to Open LoopClosed LoopOpen LoopThe ECU will move fromClosed Loop to Open Loop ifsudden changes in MAP, ECT,or RPM values occur.MAP sensor changes are loaddependent. ECT changes arecoolant related. RPM changesare engine running Slide 44
zzzEMSZEEMSClosed Loop Operation“Condition”“Command”“R“L ich”e“R an”ich ”ECUElectronicControlUnitLeaRi n OchuLeen tanOutEGOFuel InjectorENGINESlide 45
zzzEMSZEEMSReviewQuestions andAnswersOperation ReviewSlide 46
zzzEMSZEEMSKey OnCalculates or measures: Altitude, barometric pressure Coolant temperature Ambient temperatureECUElectronicControlUnitMAPECTIATECU Turns on Fuel Pump(gasoline)orOpens Fuel Lock Off(propane)This will be “on” for2 seconds if a RPM signalis not received.Listen and “feel” the pumprun or the lock off to “turn on”.Slide 47
zzzEMSZEEMSCrankingFuel is flowingECUElectronicControlUnit(pump “pumping”or lock off “open”)Injector FiringMAPRPMECTGovernor isstarting tocontrolIATSlide 48
zzzEMSZEEMSRunningwithout EGO SensorThrottlePedalCommandFuel is flowingECUElectronicControlUnit(pump “pumping”or lock off “open”)Injector FiringMAPGovernor is at specifiedcontrolled RPMRPMECTIATSlide 49
zzzEMSZEEMSRunningwith EGO SensorEGOThrottlePedalCommandEGOKey OnNot ECUHeaterControlledFuel is flowingECUElectronicControlUnit(pump “pumping”or lock off “open”)Injector FiringMAPGovernor is at specifiedcontrolled RPMRPMECTIATIgnition TimingadvancingSlide 50
zzzEMSZEEMSOperationReviewSystem OperationReviewQuestions and AnswersSlide 51
ZEEMSzzzEMSDiagnosticsSlide 52
ZEEMSzzzEMS A Service kit is available to diagnose all system components.Zenith part number is C282-311Slide 53
zzzEMSZEEMSDiagnosticsECU testing:Black15819White1523816123169Slide 54
zzzEMSZEEMSDiagnostics White ConnectorPin #1234567891011121314151617181920212223Wire ColorDescriptionYellow12v LP RequestBrown/whiteLP Injector (Ground)BrownGas Injector (Ground)Purple12v output for fuelTansignal to GovernorEmptyEmptyGray12v thru 10K resistor to pin 1112v input (speed, oil switch)EmptyGray5v from resistor pin 8Red/White Ground to diagnostic lightEmptyRed/White 12V Neutral SwitchRed/Black 12V InjectorEmptyYellow/Green 12V input (speed,oil)EmptyBlueDistributor input (digital k Wire Color DescriptionGreenCoolant SensorWhitePot input 0-5 VGreen/black 5V output (pot)Orange5V output (MAP)Yellow/Black (speed ground)Empty (programming port)Pink12V to oilswitchOrange/Black Self-Learn/fault lamp resetBlueAir Temp SensorWhite/Black 02 sense inputBlackAll Sensor GroundBlack/White Signal ground for 02/pedalRed/Black(speed ground)EmptyWhite/Black (speed ground)GrayIdle validation 5VlGreenMAP Sensor 5V inputEmptyEmptyEmptyEmptyEmptyEmptySlide 55
ZEEMSzzzEMSDiagnostics Processor Quick Testsrefer to previous chart Conclusion If all of these tests fail, suspect a faulty power or groundcircuit/s to the ECU. If one or two of these tests fail, suspect a faulty ECU.Slide 56
ZEEMSzzzEMS Input Sensor Quick Tests IAT TestingECT TestingMAP TestingEGO TestingDistributor ReferenceSlide 57
zzzEMSZEEMS IAT and ECT Testing Remove wiring harness from sensor/s Install “test harness” to IAT or ECT sensor Measure the resistance values in Ohmsand compare to chart belowTemp F2662302121761401046832-4-40Temp 1511993697341579371997672910101400Slide 58
ZEEMSzzzEMS IAT and ECT Testing Remove wiring harness from sensor/s Turn Key On (KOEO) Measure voltage between terminals “A” & “B”of the wiring harness going to the IAT or ECT Black Voltmeter lead to “B”, red lead to “A” Voltage should be 5 vDC /- 10% (KOEO)Slide 59
zzzEMSZEEMS MAP Testing Complete ECU reference voltage test at MAP With the MAP connected “in-circuit” Connect a voltmeter as follows, key on (KOEO) Red lead to terminal “B”, black lead to ground Measure the Voltage values and compare to chart These voltages will vary according the current weatherconditions at your locationAltitudeabove ltage DC5.00-4.604.60-4.104.10-3.603.60-3.20Slide 60
zzzEMSZEEMS EGO Testing(if equipped) Complete EGO Bias voltage test With the EGO connected “in-circuit” Connect a voltmeter as follows, key on (KOEO) Red lead to Cavity “B”, black lead to Cavity “A”. Complete EGO test in machine per EGO testingsequence ‘Richen Mixture’ EGO voltage 0.8 vDC or higher ‘Lean Mixture’ EGO voltage 0.3 vDC or lower A ground B Sense C system ground D 12VIGN (heat)Slide 61
zzzEMSZEEMS EGO Bias Voltage Test (KOEO, Black Connector Pin 10)(if equipped) Measure “Bias” voltage to EGO Sensor Turn Key OffLeave harness installed to EGOStart EngineVoltmeter red lead to Cavity “B” on EGO SensorConnector, black lead to Cavity “A”Results should be 0.1 - 0.9 vDC when sensor is activatedand engine running.Slide 62
zzzEMSZEEMS Fuel InjectorTesting Disconnect wire/s to fuel injector Measure the resistance of the fuel injector 1.2 - 1.6 Ohms is specification Turn Key on and measure voltage on theharness Volt meter red lead to terminal “A”, black lead toterminal “B”, turn key on (KOEO) Voltage is pulsing but can be seen. Noid light isbest for this test. Complete fuel injector “tap test”Slide 63
zzzEMSZEEMS Governor ActuatorTesting Disconnect wire/s to Governor Actuator Measure the resistance of the actuator 3.0-4.5 Ohms is specification Turn Key on and measure voltage on theharness Volt meter red lead to terminal “A”, black lead toterminal “B”, turn key on (KOEO) Voltage is Pulse Width Modulated and could varybetween 2.3V and 6.2VSlide 64
zzzEMSZEEMS Ignition TimingTesting Start engine and monitor ignition timing From idle up to 1000 RPM, the ignition timingshould be close to base timing setting Manual Advance of engine timing occursthrough a vacuum port located on ThrottleBody. If the ignition timing does not advance,suspect in this order; Vacuum hosedisconnected,Vacuum port clogged,Distributor malfunctionSlide 65
zzzEMSZEEMS Diagnostic Review (Failure Mode) 85% Wiring 10% Input sensors 4% Actuator outputs 1% ECU Failures85%Wiring10%InputSensors1% ECU Failures4%ActuatorOutputsSlide 66
zzzEMSZEEMSIAT and ECTTemp F2662302121761401046832-4-40Temp 3496931484348190992705093630MAPAltitudeabove ltage DC5.00-4.604.60-4.104.10-3.603.60-3.20Fuel 97672910101400GovernorActuator3.0-4.5 Ohms1 amp max currentdraw1.2 - 1.4 OhmsFuel Pressure Gasoline10-12 psi(open Loop)14psi(closed Loop) Propane22-24 psi.(open Loop)15psi(closed Loop)Slide 67
zzzEMSZEEMSDiagnostics, No Start No StartQuick Tests Determine the following when‘cranking’ the engine No Fuel, with spark plugs ‘firing’ No Spark, with fuel injection spray from injector Both No Fuel Spray and No Ignition SparkSlide 68
ZEEMS No Start: No Fuel, w/sparkzzzEMSQuick Tests Check fuel level in tank and fuel filter for blockage Listen for fuel pump run or lock off ‘click’ for thefirst two seconds after the key is turned on and lefton. If no lock off ‘click’ or fuel pump run, suspect faultywiring to pump/lock off, if o.k suspect faultypump/lockoff.Slide 69
zzzEMSZEEMSTap Test No Start: No Fuel, w/sparkQuick Tests(Tap Test) If the fuel pump runs or the lock off ‘clicks’, operate the fuelinjector manually as follows: Cycle “key” several times (off-on-off-on-off) Disconnect wiring harness to the fuel injector Connect one terminal of the injector to the battery plus(B ) with a fused jumper lead. Connect a test light to ground Tap the other terminal of the injector with the test lightprobe. When “tapped”, the test light should light and the injectorshould spray fuelSlide 70
ZEEMSzzzEMS No Start: No Fuel, w/spark (Tap Test) If the fuel injector does not spray fuel and test light‘lights’ (a small ‘click’ from the fuel injector will be heard when test light istapped, no ‘click’ is a faulty fuel injector): Suspect fuel is not ‘getting to the injector’ or the fuelinjector fuel passage is plugged If the fuel injector does not spray fuel and test light‘does not light’ when tapped: Suspect a faulty (open) fuel injector If the fuel injector sprays fuel when tapped: Suspect the fuel injector is not receiving “signal/s” fromthe ECU, a defective RPM signal to the ECU or a faultyECU.Slide 71
zzzEMSZEEMSDiagnostic Trouble CodesResult – What the ECU will do when it detects a fault condition.Trouble Code – The code that will be displayed by the Engine Check Light.Trouble Flag – Code that will be displayed on a laptop using the Zenith monitoring software while the engine is running.Code/Flag retained in memory with key off? – Which flags and codes that will be retained for retrieval when the key is turned off.Check Engine Light – The engine check light condition that the operator will see when a fault condition occurs.Trouble Code Operation:When the Engine Check Light is on continuous there will be trouble codes stored to retrieve.To retrieve codes:1. With the engine off, turn the key to the on position.2. The engine check light will flash once pause and flash twice to indicate a code 12. Code 12 indicates that the faultsystem is functioning. Code 12 will be flashed 3 times with a double pause between each.3. The next trouble code will be displayed in the order of occurrence. It will also be flashed three times with a doublepause between each.4. After all trouble codes have been flashed three times, the codes will repeat starting with code 12.To clear the codes:1. After all of the codes have been retrieved and conditions repaired, start the engine. With the engine running,momentarily ground the self learn wire. You will hear the engine hesitate as the ground is made and the enginecheck lSlide 72
zzzEMSZEEMSCONDITION1ENGINE OIL PRESSURE SWITCHINDICATES LOW OIL PRESSURE2ENGINE OVERHEATING DETECTED(COOLANT 239 F)345TRANSMISSION OIL TEMPERATURESWITCH INDICATES AINED INMEMORY WITH KEYOFF?OIL PRESSURE SWITCH INDICATES OIL PRESSURE IS LOW FOR 1COMPLETE SECOND - ENGINE SHUTDOWN OCCURS2NO1RPM LIMITED TO 950 MAXIMUM FOR 60 SECONDS3NO2ONCE 60 SECOND TIME LIMIT IS EXCEEDED - ENGINE SHUTDOWNOCCURS3NO1RPM LIMITED TO 950 MAXIMUM FOR 60 SECONDS4NO2ONCE 60 SECOND TIME LIMIT IS EXCEEDED - ENGINE SHUTDOWNOCCURS4NONO FAULT CONDITION EXITS - SIGNIFIES BEGINNING OF FLASHCODES121TROUBLE CODE IS STORED IN MEMORY1432RPM LIMITED TO 950 MAXIMUM FOR 60 SECONDS1433ONCE 60 SECOND TIME LIMIT IS EXCEEDED - ENGINE SHUTDOWNOCCURS143BEGINNING OF DIAGNOSTIC ROUTINEENGINE COOLANT SENSOR INDICATESSHORT CIRCUIT OR EXTREMEOVERHEATING OF ENGINE (COOLANTTEMP 266 F)RESULTYES-ALWAYSPRESENTCODE RETAINED INMEMORYFLAG CLEARSWHEN IGNITION ISOFFFLAG CLEARSWHEN IGNITION ISOFFCODE RETAINED INMEMORY6ENGINE COOLANT SENSOR INDICATESOPEN CIRCUITTROUBLE CODE IS STORED IN MEMORY157PEDAL POSITION SENSOR OVERVOLTAGE (OVER 4.5 VOLTS)TROUBLE CODE IS STORED IN MEMORY21CODE RETAINED INMEMORY8PEDAL POSITION SENSOR UNDERVOLTAGE (0 VOLTS)TROUBLE CODE IS STORED IN MEMORY22CODE RETAINED INMEMORY9AIR TEMPERATURE SENSOR INDICATESOPEN CIRCUITTROUBLE CODE IS STORED IN MEMORY23CODE RETAINED INMEMORY10AIR TEMPERATURE SENSOR INDICATESSHORT CIRCUITTROUBLE CODE IS STORED IN MEMORY24CODE RETAINED INMEMORY11MAP SENSOR CIRCUIT INDICATES HIGHVLOTAGE (4.98 V OR ABOVE)TROUBLE CODE IS STORED IN MEMORY33CODE RETAINED INMEMORY12MAP SENSOR CIRCUIT INDICATES SHORTTO GROUNDTROUBLE CODE IS STORED IN MEMORY34CODE RETAINED INMEMORY13OXYGEN SENSOR - LEAN CONDITIONDETECTEDTROUBLE CODE IS STORED IN MEMORY44CODE RETAINED INMEMORY14OXYGEN SENSOR - RICH CONDITIONDETECTEDTROUBLE CODE IS STORED IN MEMORY45CODE RETAINED INMEMORYSlide 73
ZEEMSzzzEMS Both No Fuel Spray and No Ignition SparkQuick Tests Visually inspect system wiring and correct defects Verify the ground (battery ground) to the ECU iscorrect (White Connector 20 and 21) in KOEO,and cranking modes Verify the power (battery feed) to the ECU iscorrect (White Connector 22 and 23) in KOEO,and cranking modesSlide 74
ZEEMSzzzEMSLaptop DiagnosticsSlide 75
zzzEMSZEEMSLaptop DiagnosisCommunication Interface Instruction SheetMonitoring Engine Data2.9.1. Copy all files from provided disk onto computer hard drive. (This step necessary for first time use only.)Recessed buttons located to the right of serial cable connection of the communication box are not to be depressed. (located thru drilled holes)3.Disconnect the BLACK connector on wiring harness from mating connector on Z.E.E.M.S. ECU.4.Connect the BLACK connector on communication interface to mating connector on Z.E.E.M.S. ECU.5.Connect the BLACK connector on wiring harness to mating connector on communication interface.6.Connect 9-pin serial cable between computer serial port and communication interface.7.Open Nissan.exe on computer.8.Select appropriate *.cfg file for the application (i.e. Nfcna.cfg).“ECU Online” is displayed in the lower right corner of the screen and the current operating data is displayed at the top of the screen when key power isapplied or the engine is running.Special FunctionsUPLOADUse the UPLOAD command in the FILE menu to receive the latest EDU data (key power must be on).SAVEUse the SAVE command in the FILE menu to store ECU data in file.OPENUse the OPEN command in the FILE menu to retrieve previously stored data.PLOTUse the PLOT function to display operating parameters graphically. In the PLOT menu select a variable to graph from the list and center a valid graphing scale.Slide 76
zzzEMSZEEMSBlock Diagram ReviewZEEMS Block DiagramElectrical fuel shut off/on, propane (LPG)Electric fuel pump, gasolineInput SensorsRPMFuel Return,gasoline onlyDistributorTimingAdvanceThrottle ActuatorFuel Tank,propaneorgasolineECUElectronicControlUnitFuel InjectorSlide 77
zzzEMSZEEMSRunningwith EGO SensorEGODash SwitchCommandEGOKey OnNot ECUHeaterControlledFuel is flowingECUElectronicControlUnit(pump “pumping”or lock off “open”)Injector FiringMAPGovernor is at specifiedcontrolled RPMRPMECTIATIgnition TimingadvancingSlide 78
zzzEMSZEEMSZEEMSZenith Electronic Engine Management SystemPropane and GasolineElectronic Fuel InjectionENDSlide 79
t s, E G O EGO Exhaust Gas Oxygen Sensor ECU Electronic Control Unit EGO ECU Inputs The EGO generates voltages between 0-1vDC. The ECU “monitors” the signal wire to determine the O2 content of the exhaust stream. ECU monitors here EGO Heater EGO (if equipped) Key Switch On. zzzEMS Slide 25
Doctor to Zenith: Zenith Insurance Company Attention: ZHCN P.O. Box 1558 Sarasota, FL 34230-1558 1-800-841-3987 If you are not happy with the alternate Treating Doctor, you must contact Zenith t o submit a request for additional changes. Contact Zenith at 1-800-841-3987 to submit your request. Zenith will review your request
The Zenith Carburetor (revised 2010) by Tom Endy Zenith carburetor documentation: Good grief! Another article on the Model A Ford Zenith carburetor. Enough already! There must be a whole floor in the library of congress devoted to articles written about this carburetor. But wait! If you are into rebuilding Zenith carburetors you might want to .File Size: 532KB
1.Engine Oil SABA 13 1.Engine Oil 8000 14 1.Engine Oil 6000 15 1.Engine Oil 3000 16 1.Engine Oil Alvand 17 1.Engine Oil Motor Cycle Engine Oil M-150 18 1.Engine Oil M-100 19 1.Engine Oil Gas Engine Oil CNG-BUS 20 1.Engine Oil G.I.C.X.LA 21 1.Engine Oil G.I.C.X. 22 1.Engine Oil Diesel Engine Oil Power 23 1.Engine Oil Top Engine 24
Your client firm is Zenith Medical Systems Incorporated. Zenith was formed as a joint venture of a major computer firm and a leading supplier of hospital products and opened its doors for business on January 1, 2012. Both firms invested an equal amount of capital in the venture. Top management for Zenith was provided from the ranks of the .
Zenith portable, (sailboat) Zenith G503Y portable Zenith B600 Transoceanic Zenith H500 transoceanic Additionally we advertised that the Cra w-ford three dialer, (the 10,000 radio) would be auctioned. This is still under consideration.
To the Management of Zenith National Insurance Corp. We have audited the accompanying consolidated financial statements of Zenith National Insurance Corp. and its subsidiaries, which comprise the consolidated balance sheets as of December 31, 2020 and 2019, and the related consolidated statements of comprehensive income,
and Mary Barton Smith made generous gifts to advance health systems engagement in Northern California. The Zenith Society sets the bar for philanthropic leadership, engagement and impact. ZENITH SOCIETY MEMBERS ADVANCE KEY INITIATIVES Mary Barton Smith (front left) and Dagmar Dolby (front right) with other Zenith Society members
zenith carburetor cross reference for major industrial engines call 1-800-245-0711 or click "price & availability" for price, availability & to order online zenith replacement carburetors for allis chalmers, baker internatio
