® AfterSales Training Fuel/Ignition Diagnosis & Repair P21 Porsche AfterSales Training Student Name: Training Center Location: Instructor Name: Date: _ Electrical Troubleshooting Logic - Do you understand how the electrical consumer is expected to operate? - Do you have the correct wiring diagram? - If the circuit contains a fuse, is the fuse okay & of the correct amperage? - Is there power provided to the circuit? Is the power source the correct voltage? - Is the ground(s) for the circuit connected? Is the connection tight & free of resistance? - Is the circuit being correctly activated by a switch, relay, sensor, microswitch, etc.? - Are all electrical plugs connected securely with no tension, corrosion, or loose wires? Important Notice: Some of the contents of this AfterSales Training brochure was originally written by Porsche AG for its restof-world English speaking market The electronic text and graphic files were then imported by Porsche Cars N.A, Inc and edited for content Some equipment and technical data listed in this publication may not be applicable for our market Specifications are subject to change without notice We have attempted to render the text within this publication to American English as best as we could We reserve the right to make changes without notice © 2012 Porsche Cars North America, Inc All Rights Reserved Reproduction or translation in whole or in part is not permitted without written authorization from publisher AfterSales Training Publications Dr Ing h.c F Porsche AG is the owner of numerous trademarks, both registered and unregistered, including without limitation the Porsche Crest®, Porsche®, Boxster®, Carrera®, Cayenne®, Cayman™, Panamera®, Tiptronic®, VarioCam®, PCM®, 911®, 4S®, FOUR, UNCOMPROMISED.SM and the model numbers and distinctive shapes of Porsche's automobiles such as, the federally registered 911 and Boxster automobiles The third party trademarks contained herein are the properties of their respective owners Specifications, performance standards, options, and other elements shown are subject to change without notice Some vehicles may be shown with non-U.S equipment Porsche recommends seat belt usage and observance of traffic laws at all times Printed in the USA Part Number - PNA P21 004 Edition 9/12 Table of Contents Chapter Description Section Introduction i System Type Designations Engine Mechanical Intake Systems Ignition System Fuel Supply Systems Exhaust Systems Mixture Formation On-Board Diagnostics (OBD II) Additional DME Functions & Special Control Systems Conversion Charts 10 Fuel/Ignition Diagnosis & Repair Fuel/Ignition Diagnosis & Repair Introduction Over the past several years, the engine management and related systems of Porsche vehicles have had to respond to ever-lower emissions standards and increasingly complex legislative requirements While each new engine design produced more torque and horsepower and lower fuel consumption, engine management systems become increasingly efficient and complex This has increased the amount of information that the technician must have command of and the complexity of the systems the technican must understand, exponentially This training book attempts to organize the information and system theory of Porsche engine management in an understandable and organized manner We hope this will make your study of Porsche engine management a successful undertaking that will improve your ability to repair and diagnose Porsche engine management systems Viel Spass! AfterSales Training Department Fuel/Ignition Diagnosis & Repair Page i Page ii Fuel/Ignition Diagnosis & Repair System Type Designations Model Year – Porsche System Designations Model Model Year System Designation 911 1984-89 DME 35 Pin Control Unit 911 (964) 1989-94 DME 55 Pin Control Unit 911 (993) 1995 DME 2.10.1 911 (993) 1996-98 DME 5.2 911 (996) 1999 DME 5.2.2 911 (996) 2000-01 DME 7.2 911 (996) 2002-05 DME 7.8 911 (997) 1st Gen .2005 DME 7.8 911 (997) 1st Gen .2006-08 DME 7.8_40 911 (997) 2nd Gen DFI 2009-11 EMS SDI 3.1 (Siemens) 911 (991) 2012-on EMS SDI (Continental) 911 Turbo 1986-89 CIS 911 Turbo (964) 1991-94 K-Jetronic, Electronic Ignition System EZ 69 w/Spark Control 911 Turbo (993) 1996-98 DME 5.2 911 Turbo (996) 2001-05 DME 7.8 911 Turbo (997) 2006-09 DME 7.8.1 911 Turbo (997) DFI 2010-12 EMS SDI 3.1 (Siemens) 924S 1986-88 DME 35 Pin Control Unit 928 S 1984-86 LH-Jetronic - EZF 928 S4 1987-89 LH-Jetronic - EZK 928 S4/GT 1990-95 LH-Jetronic - EZK 944 1984-89 DME 35 Pin Control Unit 944 S 1987-89 DME 55 Pin Control Unit 944 S2 1990-91 DME 55 Pin Control Unit 944 Turbo 1986-90 DME 35 Pin Control Unit with KLR 968 1992-95 DME 2.10.1 Boxster/S (986) 1997-99 Boxster/S (986) 2000-02 Boxster/S (986) 2003-04 Boxster/S (987) 1st Gen .2005-08 Cayman/S (987) 1st Gen .2006-08 Boxster (987) 2nd Gen (2.9 liter) 2009-12 Cayman (987) 2nd Gen (2.9 liter) 2009-on Boxster S (987) 2nd Gen (3.4 liter) DFI 2009-12 Cayman S (987) 2nd Gen (3.4 liter) DFI 2009-on Boxster/S (981) DFI 2012-on DME 5.2.2 DME 7.2 DME 7.8 DME 7.8_40 DME 7.8_40 DME 7.8.2 DME 7.8.2 EMS SDI 3.1 (Siemens) EMS SDI 3.1 (Siemens) EMS SDI 9.1 (Continental) Cayenne (V6) 1st Gen .2004-06 Cayenne S 1st Gen .2003-06 Cayenne Turbo 1st Gen .2003 06 Cayenne (V6) 2nd Gen (E1) DFI 2008-10 Cayenne S 2nd Gen (E1) DFI 2008-10 Cayenne Turbo 2nd Gen (E1) DFI 2008-10 Cayenne (V6) (E2) DFI 2011-on Cayenne S Hybrid (V6) (E2) DFI 2011-on Cayenne S (E2) DFI 2011-on Cayenne Turbo (E2) DFI 2011-on DME 7.1 DME 7.1 DME 7.1 MED 9.1 (Bosch) EMS SDI 4.1 (Siemens) EMS SDI 4.1 (Siemens) MED 17.1.6 (Bosch) MED 17.1.6 (Bosch) (Hybrid Manager) EMS SDI 8.1 (Siemens) EMS SDI 8.1 (Siemens) Fuel/Ignition Diagnosis & Repair Page 1.1 System Type Designations Model Model Year Panamera (V6) DFI 2011-on Panamera S Hybrid (V6) DFI 2012-on Panamera S DFI 2010-on Panamera Turbo DFI 2010-on System Designation EMS SDI 7.1 (Siemens) MED 17.1.6 (Bosch) (Hybrid Manager) EMS SDI 6.1 (Siemens) EMS SDI 6.1 (Siemens) Carrera GT 2004-06 DME 7.1 x (Master/Slave) Page 1.2 Fuel/Ignition Diagnosis & Repair Engine Mechanical Subject Page Engine Mechanical System The Four Strokes Of The “Otto” Cycle Fuel/Ignition Diagnosis & Repair Page 2.1 Engine Mechanical The Four Strokes of the “Otto” (combustion) Cycle By dividing the engine management system into its basic systems, and subsystems, we can gain a better understanding of engine management as a whole, and the relationships between these systems The engine mechanical system compresses the air and fuel mixture provided by the fuel system and the ignition system ignites the air and fuel mixture to produce torque and horsepower at the crankshaft A solid knowledge of engine management is essential for understanding of the complex computer controlled systems utilized by Porsche today As well as being essential for the diagnosis of system faults Engine Mechanical System The engine mechanical system consists of the intake system, the engine mechanical (motor-block, pistons, valves, etc.) and the exhaust system The operational principal of this system is the “Otto” cycle The operation of an internal combustion engine can be understood by looking at the operation of one cylinder of the engine through an entire combustion cycle The combustion cycle consists of two crankshaft revolutions During each of these revolutions the piston will travel from the top of the cylinder to the bottom of the cylinder, and then from the bottom of the cylinder to the top These movements are called strokes and there are four strokes in a combustion cycle (down, up, down, up) The valve train of the engine operates the valves in synchronization with these strokes: opening the intake valve during one stroke and the exhaust valve during another stroke Intake (1) During the intake stroke the piston is moving down and the intake valve is open As the piston moves down, the air and fuel mixture enters the cylinder to occupy the space vacated by the piston as it moves down At the end of the intake stroke the piston is at the bottom of the cylinder and the intake valve closes Compression (2) During the compression stroke the piston is moving up and the valves are closed The piston movement compresses the air/fuel mixture that entered the cylinder during the intake stroke At the top of this stroke the air/fuel mixture that filled the entire cylinder at the bottom of the intake stroke has been compressed into the combustion chamber Compressing the mixture by the ratio of the total cylinder volume to the combustion chamber volume Page 2.2 Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Inputs and Outputs for Thermal Management Control Notes: Page 9.46 Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Engine Compartment Purge Fan – 911 (991) The engine compartment purge fan consists of two electrically actuated fans The fan motors can be operated at two speed settings (low and high) and are switched using two relays Operating condition: Engine switched off If the engine has been switched off, the fans can run for up to 25 minutes in order to purge the engine compartment Setting runs at an engine temperature > 180° F (82° C.) until the temperature in the engine compartment has fallen to < 158° f (70° C.) The fan motors run at fan setting until the engine temperature is < 113° F (45° C.) in order to reduce the temperature further Operating condition: Interruption of fan operation The engine compartment fan motors not have their own control unit There is one relay for each of the two settings (low/high) The fan motors are actuated on the instruction of the DME control unit Actuation takes place as a function of the engine compartment temperature, which is detected by a separate engine compartment temperature sensor The engine compartment temperature sensor is connected to the DME control unit Another variable is the engine coolanttemperature Operating condition: Engine off, ignition on Fan operation is interrupted if any of the following situations occur: • Engine compartment lid open • Cabriolet only: convertible top open • Battery voltage < 10 volts Diagnosis The engine compartment purge fan can be diagnosed using the DME control unit Drive-link diagnosis is possible using PIWIS Tester II Detected faults are stored in the DME control unit The engine compartment purge fan runs at setting when the engine compartment temperature is > 162° F (72° C.) It switches off again under these conditions when the engine temperature is < 154° F (68° C.) Operating condition: Engine on When the engine is running, fan setting is switched on when the engine compartment temperature is > 75° F (24° C.) and switched off again when the engine temperature is < 59° F (15° C.) Fan setting is switched on when the engine compartment temperature is > 149° F (65° C.) or the engine coolant temperature is > 226° F (108° C.) When the engine is running, fan setting is switched off again when the engine compartment temperature is < 145° F (63° C.) or the engine coolant temperature is < 221° F (105° C.) Fan setting is activated in the event of heavy acceleration from standstill Activation depends on the speed with which the accelerator pedal is depressed and the accelerator pedal travel (depress fully) The same applies to the launch control start on vehicles with Porsche Doppelkupplung (PDK) Fuel/Ignition Diagnosis & Repair Page 9.47 Additional DME Functions & Special Control Systems Engine Compartment Purge Fan – Boxster (981) There are engine compartment purge fans installed on the left and right in the engine compartment for cooling; these fans blow cool air into the engine compartment when required Operating condition: With the engine running: The specified values correspond to an ambient temperature > 50° F (10° C) Fan setting is switched: • “On” when intake air temperature > 77° F (25° C) • “Off” when intake air temperature < 59° F (15° C) Fan setting is switched: • “On” when intake air temperature > 149° F (65° C) • “Off” when intake air temperature < 145° F (63° C) or • “On” when engine compartment temperature > 160° F (71° C) • “Off” when engine compartment temperature < 153° F (67° C) or • “On” when coolant temperature > 226° F (108° C) • “Off” when coolant temperature < 221° F (105° C) Operating condition: Engine switched off If the ignition was switched off at an engine compartment temperature > 113° F (45° C), the DME control unit enters an “extended motor control unit run-on” mode for up to 25 minutes The engine compartment purge fans can be activated as follows in this case: Fan setting 1: The electrically activated fan motors can be operated at two speed settings (low and high) There is one relay for each of the two settings The fan motors are activated by the DME control unit Activation takes place as a function of the engine compartment temperature, which is reported to the DME control unit by an engine compartment temperature sensor installed at the intake manifold Another variable is the engine coolant temperature • “On” when engine compartment temperature > 147° F (64° C) • “Off” when engine compartment temperature < 144° F (62° C) Fan setting 2: • “On” when engine compartment temperature > 167° F (75° C) • “Off” when engine compartment temperature < 147° F (64° C) Note! Diagnosis of the engine compartment purge fans The engine compartment purge fans can be diagnosed using the DME control unit Drive-link diagnosis is possible using PIWIS Tester II Detected faults are stored in the DME control unit Page 9.48 Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Auto Start Stop Auto Start Stop Function Coordination takes place in the DME control unit • Auto Start Stop function can be activated and deactivated by way of a button in the center console • This function is available as soon as the engine has reached a coolant temperature of 113° F (45° C.) and an oil temperature of 68° F (20° C.) • The combustion engine is switched off under defined conditions shortly after the vehicle comes to a stop • Fuel consumption and emissions are reduced above all in urban driving; fuel consumption in the NEDC is reduced by up to % • Increased comfort for passengers, the noise level falls to zero during the stop phase This switches off the combustion engine under defined conditions when the vehicle is at a standstill and therefore exploits potential fuel savings, e.g unnecessary engine idling while waiting at a traffic light is prevented The Auto Start Stop function can be deactivated and activated by way of a button in the center console If the boundary conditions are met, the function is available as soon as the engine and battery have reached the corresponding temperature and the speed threshold of 1.2 mph (2 km/h) has been exceeded for at least 1.5 seconds If the vehicle is stopped by brake operation and the brake pedal is held, the Auto Start Stop func - tion switches off the engine after approx second The driver is informed about this by the green Auto Start Stop symbol in the instrument cluster The tachometer reading falls to zero The selector lever can remain in position D or M The engine remains stopped even if the lever is shifted to P and N If the engine cannot be switched off automatically, the driver is informed about this by a yellow Auto Start Stop symbol in the instrument cluster For the driver, use of the Auto Start Stop function does not mean that he/she has to change his driving behavior The driver does not have to perform any additional activities for an engine stop and restart Depending on country, the Auto Start Stop function is either switched on automatically when the ignition is switched on or must be activated each time the ignition is switched on When the Start Stop system is switched off, the indicator light in the button lights up “red” • Optimized criteria for frequent engine switch-off • The position of the crankshaft is detected by the differential Hall sensor on the crankshaft to permit fast starting • Battery monitoring (voltage, current, temperature) • The starter is reinforced (for the increased number of starting operations) • Maintains the vacuum for the brake booster A pressure sensor on the brake booster measures the vacuum: - the engine is started again by way of a veto if the pressure falls below an applicable pressure threshold - there is no other way of maintaining the vacuum when the engine is stopped The criteria described were optimized and adjusted in order to ensure that the engine is switched off automatically in as many cases as possible during regular driving operation The goal was to exploit the fuel-saving potential of the Auto Start Stop function for the driver In order to permit realization of the Auto Start Stop function, the starter was reinforced and designed for the increased number of engine starting operations In addition, the battery charge and aging condition as well as temperature are monitored in order to ensure the restart capability The vehicle assists the driver when the engine is switched off by maintaining the brake pressure on uphill slopes This was integrated as an additional function in Porsche Stability Management (PSM) This prevents the vehicle from rolling away opposite to the driving direction when the engine is switched off The most important comfort and safety functions continue to operate even when the engine is switched off For example, the audio and communication systems still operate and the lighting, airbag systems and PSM remain available These functions are supplied with power from the battery for this purpose Voltage changes when the engine stops and restarts are partially compensated for and their effects reduced The air conditioning ensures temperature comfort For this purpose, it uses the residual heat of the engine for heating or the residual cooling energy in the cooling system to cool the passenger compartment If there is a risk of the passenger compartment temperature deviating significantly from the preselected value, the engine is automatically restarted in order to guarantee continued climate comfort for the passengers Fuel/Ignition Diagnosis & Repair Page 9.49 Additional DME Functions & Special Control Systems The Auto Start Stop system has detected that: Automatic Engine Stop If the prerequisites are met, the engine is stopped as soon as the vehicle comes to a stop • Brake vehicle to a stop with the footbrake • Keep footbrake depressed • or move selector lever to position P Automatic engine stop and restart readiness (function indication) If the engine was automatically switched off under the corresponding conditions, the indicator light in the multifunction display of the instrument panel lights up “green” The Auto Start Stop system starts the engine: • In selector lever position D, N or manually selected transmission range or • Release footbrake • or press accelerator pedal • or move selector lever to position R If the vehicle is stopped by brake operation and the brake pedal is held, the Auto Start Stop function switches off the engine after approx -2 seconds The driver is informed about this by the green Auto Start Stop symbol in the instrument cluster The tachometer reading falls to zero The selector lever can remain in position D or M The engine remains stopped even if the lever is shifted to P and N Auto Engine Restart The engine is restarted when the driver releases the brake The starting operation is supported by the direct fuel injection and ignition systems so that it can take place quickly and in a way that saves energy and protects the battery To achieve this, the engine was supplemented by a sensor that detects the position of the crankshaft and therefore makes the information available as to which cylinder can be charged and ignited early As a result, the engine power required for driving away is already available again after a short time No engine stop or restart readiness (function indication) If the automatic engine stop function is not possible, the indicator light in the multi-function display of the instrument panel lights up “yellow” Page 9.50 • at least one prerequisite is not met • or at least one exception condition is present • or e.g the following faults are present: - generator fault - battery fault - DC/DC converter fault, etc If the engine cannot be switched off automatically, the driver is informed about this by a "yellow" Auto Start Stop symbol in the instrument cluster The engine is not switched off or restarted again: • if the engine has not yet reached its operating temperature • if “Sport” mode is activated • if PSM was switched off • if manoeuvering or a parking operation has been detected (large steering angle), i.e reverse gear has been engaged or the steering wheel has been turned by a large angle • if the height adjustment function of the adaptive air suspension has been selected or is active • if the vehicle stops on steep uphill or downhill gradients • if the climate control/heating with residual heat function cannot guarantee that the set temperature can be maintained without a running engine, e.g at very low and very high outside temperatures • if the total energy requirement of the vehicle systems from the battery cannot be met (charge condition) • if the rear fog light is activated • if internal vehicle operations are taking place that must not be interrupted, e.g flushing operations in the fuel system via the tank vent due to high loading of the active carbon filter • if trailer operation has been detected Restarting is also prevented: • if the presence of the driver is not guaranteed, i.e driver’s door is open or driver’s seat belt is not fastened • if the hood is open As of MY 2012 – Auto Start Stop can also be used in conjunction with the manual transmission All the driver has to is to disengage the gear (neutral position) and remove his/her foot from the clutch pedal when the vehicle is stationary, for example in a traffic jam or in stopand-go traffic The engine starts immediately when the clutch pedal is pressed again and the trip can be continued quickly and without delay Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Coasting Function Activating: • Press button (1) • The indicator light in the button goes off • Coasting mode is activated and the engine is automatically switched off when the vehicle stops Prerequisites for coasting mode: • Driving in selector lever position D • Coasting mode is activated (indicator light in the button is off) • Sport or Sport Plus mode is deactivated • PSM is active • Control cruise mode is not active • Engine, transmission and battery have reached operating temperature • Relaxed/economic driving style • Only a slight uphill or downhill gradient • Remove foot slowly from accelerator pedal The Auto Start Stop button switches the Auto Start Stop function on and off and activates and deactivates coasting mode The engine is disengaged and runs at idle speed The vehicle rolls with no engine braking effect Coasting mode can be identified by the tachometer showing idle speed The 9x1 models now feature the coasting function in conjunction with the Porsche Doppelkupplung (PDK) Coasting refers to operating the vehicle with the engine disengaged, for example on slight downhill gradients; the engine is operated at idle speed so that the function of the auxiliary systems (alternator, air-conditioning compressor, coolant pump, etc.) is maintained Deactivation of the Coasting Function During coasting, the kinetic and potential energy of the vehicle is directly used to overcome driving resistance Although no fuel is used during deceleration with deceleration fuel cutoff, the vehicle is significantly decelerated If no deceleration is desired, additional fuel must be used to cover the lost distance Automatically With a sporty driving style or if the accelerator pedal is released suddenly, coasting mode is suppressed to allow targeted use of the engine braking effect Likewise, coasting does not occur on steep uphill gradients since the coasting phase would be very short due to the uphill gradient and no significant fuel saving is possible Coasting mode is suppressed on steep downhill gradients since the vehicle does not slow down, despite the engine deceleration torque, and the use of deceleration fuel cutoff means that no fuel is consumed in this driving situation Coasting mode is activated and deactivated using the Auto Start Stop button Manually • Press the accelerator pedal or • Press the brake pedal or • Press a shifting paddle or a shift button or • Change gears using the selector lever Deactivating: Activation of the Coasting Function Activating and Deactivating Coasting Mode • Press button (1) • The indicator light in the button lights up red • Coasting mode is deactivated and automatic stopping of the engine is suppressed If coasting mode is suppressed, for example due to a sporty driving style, sudden release of the accelerator pedal or excessively low engine temperature, it can be initiated manually by shifting up a gear with the shift paddle, one of the shift buttons or the selector lever Fuel/Ignition Diagnosis & Repair Page 9.51 Additional DME Functions & Special Control Systems Coasting is automatically prevented in driving situations where it no longer makes sense or would be counterproductive: if the vehicle speeds up on steep downhill gradients despite trailing throttle fuel cutoff, it is better to exploit the full fuel saving produced through trailing throttle fuel cutoff The coasting phase would be too short in the case of steep uphill gradients Coasting is suppressed during sporty driving so as to enable more direct responsiveness and not interrupt the flow of driving with frequent disengagement and engagement Driving situation shown in the graphic: The driver wants to reduce the vehicle speed from 62 mph (100 km/h to 50 mph (80 km/h) a.) Vehicle without coasting function: Steady driving and then braking with engine deceleration (without fuel injection) (red curve) b.) Vehicle with coasting function: Activation coasting mode and deceleration at idle speed fuel consumption (green curve) The driving curve with coasting is more fuel efficient because the total idle speed consumption during the coasting phase (green block) is less than the total consumption during steady driving (red block) This also works with much smaller differences in speed (< mph (5 km/h) and in other driving situations, e.g slight downhill gradients If the driver indicates a wish to decelerate by pressing the brake or intervenes manually by pressing the downshift button, the engine is re-engaged in order to use the engine's trailing throttle fuel cutoff; the fuel supply is interrupted during this process and the engine braking effect shortens the vehicle's stopping distance once more The driver can also actively suppress coasting by quickly removing his/her foot from the accelerator pedal (e.g approaching a bend, aborting a passing attempt) Coasting can also be triggered when specifically desired by the driver by pressing the upshift button in the highest gear (accelerator pedal not pressed) Engagement takes place automatically during acceleration Prerequisites for coasting mode: • Driving in selector-lever position D • Coasting mode is switched on (Auto Start Stop not deactivated using switch) • Sport or Sport Plus mode is deactivated • PSM is active • Engine, transmission and battery have reached operating temperature • Relaxed/economic driving style • Slight uphill or downhill gradient • Remove foot slowly from the accelerator pedal Ending coasting mode: • Press the accelerator pedal or • Press the brake pedal or • Change gears using the selector lever Coasting mode can be deactivated using the Auto Start Stop switch Notes: Page 9.52 Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Vehicle Electrical System Recuperation in Communication With Gateway Control Unit • This control operation includes the DME control unit, the gateway control unit, the brake pedal sensor, starter battery with battery sensor, the generator and the vehicle electrical system • Vehicle electrical system recuperation helps to reduce fuel consumption • Some of the kinetic braking energy is converted into electrical energy via the generator during vehicle deceleration phases and is fed into the starter battery • As a result, the combustion engine has to supply less power to charge the battery through generator operation in acceleration phases • Depending on the battery condition, the vehicle voltage is raised and lowered correspondingly and varies between 12.5 and 15.5 V Porsche vehicles feature the new function of vehicle electrical system recuperation as a further fuel-saving measure Here, some of the kinetic braking energy can be converted into electrical energy via the generator during vehicle deceleration phases and stored in the starter battery As a result, the combustion engine has to supply less power to charge the battery through generator operation in acceleration phases in particular, which directly results in lower fuel consumption The starter battery is preferably charged by the usually otherwise lost braking energy during the braking operation During braking, the generator output is increased in a targeted manner by the generator regulator and the recuperated energy is fed into the starter battery The voltage is then lowered again and the energy can be fed into the vehicle electrical system in order to supply the loads The increased generator power acts with a low braking torque on the crankshaft of the combustion engine via a drive belt This leads to vehicle deceleration and therefore supports the conventional brake system A new intelligent algorithm in the energy management system evaluates various input variables of the components involved, thereby allowing active coordination of every recuperation operation based on the battery charge condition and driver request This control operation includes, among others, the engine control, brake pedal sensor, starter battery with sensor system, generator and the vehicle electrical system The powerful AGM battery meets all requirements with respect to battery life in view of the increased number of cycles due to frequent charging and discharge Increase Idle Speed to Increase the Charging Current The idle speed can be increased in three stages after a corresponding request from the gateway The charging current of the generator is increased as a result The field current is regulated in the gateway To increase the generator output, the idle speed can be increased in three stages when the engine is warm (e.g V8 engines 640, 740 and 850 rpm) Sport Button Allows the driver to choose between a setup with optimized comfort and consumption or a sporty setup Standard Setting In Normal mode, the electronic engine management system restricts the engine torque in order to optimize fuel consumption (except during kickdown) • Optimized comfort and fuel consumption • Dynamically comfortable accelerator characteristic Sport Mode When the Sport button is activated, a “SPORT” symbol lights on the instrument cluster A sportier vehicle setup is obtained when Sport mode is switched on • Auto Start Stop function deactivated • Sporty engine setup • Accelerator reacts more quickly, more spontaneous throttle response • Throttle open further for same pedal travel • Coolant temperature is reduced The electronic engine management system controls the engine with more bite The dynamic response of the engine then becomes even more direct On vehicles with 8-speed Tiptronic S, up shifts take place later and downshifts earlier in automatic mode The Auto Start Stop function is also deactivated In addition, the chassis control systems Porsche Active Suspension Management (PASM) and the optional Porsche Dynamic Chassis Control (PDCC) if equipped are switched to Sport mode Fuel/Ignition Diagnosis & Repair Page 9.53 Additional DME Functions & Special Control Systems This makes damping sportier and the steering behavior in bends is more direct This in turn leads to improved road contact Activation of the Sport button influences the areas DME, Tiptronic S, PTM, PASM and PDCC Sport Plus Button (Optional Equipment) • • • • • • Communication with Adaptive Cruise Control (ACC) In communication with the control unit of the adaptive cruise control, it is possible to perform acceleration or deceleration via the electronic throttle and where appropriate braking, also to vehicle stop Auto Start Stop function deactivated For even sportier setup Performance-orientated Turbo with overboost Coolant temperature is lowered Activation of the shift indicator Off-road Mode for Cayenne • In off-road mode, the accelerator pedal characteristic is very flat at low speed in order to ensure precise throttle control when driving off-road • At faster speeds, the accelerator pedal characteristic becomes increasingly more responsive for better handling on sand dunes Notes: Page 9.54 Fuel/Ignition Diagnosis & Repair Additional DME Functions & Special Control Systems Systems That Effect Engine Management System Operation Via Data Transfer There are several systems that have effect on the operation of engine management via programs in the engine management control unit that utilize data from other systems Tiptronic Transmission Porsche has had the engine management system act on information from the transmission going back to the 928 The 928 has a switch that closes when the transmission shifts from 1st to 2nd so the ignition control can retard the ignition timing to soften the upshift All Porsche vehicles with Tiptronic and PDK transmissions have communication between the engine management control and transmission control so the transmission and engine can operate in coordination The data transfer is bi-directional with load, RPM, throttle position, “ambient conditions” and engine temperature transferred from engine management to transmission control, and requests to retard ignition timing and gear selector position are sent from transmission control to engine management When the engine is cold, the transmission control engages a catalyst warm up shift program to speed catalyst warm up This is why the transmission control is OBD-II relevant and why the MIL can be turned on by the transmission control unit In 1997, the Boxster was the first Porsche vehicle to utilize a CAN bus system It was used to connect the Tiptronic control unit to the Engine Management Control Unit Fuel/Ignition Diagnosis & Repair Page 9.55 Additional DME Functions & Special Control Systems Stability Management Sport Chrono The 1995 911 Carrera (993) was equipped with ABD (automatic brake differential) Porsche traction control began to utilize information from the engine management system ABD actuates the rear brakes to eliminate wheel slip and it utilizes load information from engine management to determine the limit for brake actuation (when load is high the brake application time limit is shortened) The 2005 911 Carrera (997), Boxster (987) and 9x1s have Sport Chrono as an option, when this system is active the engine management switches the E-throttle to a faster rise of the throttle opening curve and a more aggressive RPM limiter Sports Chrono Functions of the Motronic As Porsche stability management has evolved, the interaction between engine management and stability management has become more complex with more data shared between systems and more intervention in engine management by stability management Traction Control (TC) The 1997 Boxster (986) introduced TC (traction control), this combined ABD and ASC (anti-slip control) When this system detects a poor traction condition, it will limit the amount of torque that the engine produces The engine management can reduce the amount of fuel injected, and retard the ignition timing to reduce torque to the limit determined by ASC ASC remains a component of subsequent stability management systems, with E-throttle, the engine management has control of throttle position as well as the timing and fuel metering This allows E-throttle to control the amount of torque produced very precisely E-throttle Characteristic Engine Drag Control (EDC) The 911 Carrera (996) in 1999 came equipped with PSM (Porsche Stability Management) with ASC as an element of the system Another engine management related system component is EDC (Engine Drag Control) When EDC detects the rear wheels braking loose when decelerating with engine braking, it instructs the engine management control to open the throttle to reduce the amount of engine braking produced Page 9.56 Speed Limiter Characteristic Fuel/Ignition Diagnosis & Repair Conversion Charts Metric Conversion Formulas Temperature Conversion INCH X MM X MILE X KM (KILOMETER) X OUNCE X GRAM X POUND (lb) X kg (KILOGRAM) X CUBIC INCH X cc (CUBIC CENTIMETER) X LITERS X CUBIC FEET (cu.ft.) X CUBIC METERS X FOOTPOUND(ft lb) X Nm (NEWTON METER) X HORSEPOWER (SAE) X HORSEPOWER (DIN) X Kw (KILOWATT) X HORSEPOWER (SAE) X MPG (MILES PER GALLON) X BAR X PSI (POUND SQUARE INCH) X GALLON X LITER X FAHRENHEIT CELSIUS X 25.4 0394 1.609 621 28.35 0352 454 2.2046 16.387 061 0353 28.317 35.315 1.3558 7376 746 9861 1.34 1.014 4251 14.5 0689 3.7854 2642 32÷1.8 1.8+32 Fuel/Ignition Diagnosis & Repair = = = = = = = = = = = = = = = = = = = = = = = = = = MM INCH KILOMETER (KM) MILE GRAM OUNCE KILOGRAM (kg) lb (POUND) CUBIC CENTIMETER (cc) CUBIC INCH CUBIC FEET (cu.ft.) LITERS CUBIC FEET (cu.ft.) NEWTON METER (Nm) ft lb (FOOT POUND) KILOWATT (Kw) HORSEPOWER (SAE) HORSEPOWER (SAE) HORSEPOWER (DIN) Km/l (KILOMETER PER LITER) POUND/SQ INCH (PSI) BAR LITER GALLON CELSIUS FAHRENHEIT Page 10.1 Conversion Charts Notes: Page 10.2 Fuel/Ignition Diagnosis & Repair Part Number - PNA P21 004 ... ability to repair and diagnose Porsche engine management systems Viel Spass! AfterSales Training Department Fuel/ Ignition Diagnosis & Repair Page i Page ii Fuel/ Ignition Diagnosis & Repair System... 10 Fuel/ Ignition Diagnosis & Repair Fuel/ Ignition Diagnosis & Repair Introduction Over the past several years, the engine management and related systems of Porsche vehicles have... of our complex system(s) and performing diagnostics Notes: Fuel/ Ignition Diagnosis & Repair Page 2.3 Engine Mechanical Page 2.4 Fuel/ Ignition Diagnosis & Repair Intake Systems Subject Page General