® AfterSales Training Advanced Fuel & Ignition Diagnosis P25 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 © 2013 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®, Speedster®, Spyder®, 918 Spyder®, Tiptronic®, VarioCam®, PCM®, PDK®, 911®, 4S®, FOUR, UNCOMPROMISED.® and the model numbers and the distinctive shapes of the Porsche automobiles such as, the federally registered 911 and Boxster automobiles The third party trademarks contained herein are the properties of their respective owners Porsche Cars North America, Inc believes the specifications to be correct at the time of printing Specifications, performance standards, standard equipment, options, and other elements shown are subject to change without notice Some options may be unavailable when a car is built Some vehicles may be shown with non-U.S equipment The information contained herein is for internal use only by authorized Porsche dealers and authorized users and cannot be copied or distributed Porsche recommends seat belt usage and observance of traffic laws at all times Part Number - PNA P25 002 Edition - 3/13 Introduction In this course we will examine Porsche engine management systems, with the focus of diagnosing engine management malfunctions utilizing data from the PIWIS Tester and Information Media resources As we examine the engine management system utilized on Porsche vehicles, we will discover that these systems are enfolded by OBD-II, and that a solid understanding of OBD-II is essential to allow for accurate and timely diagnosis Subject Section Diagnostics Information Media Advanced Fuel & Ignition Diagnosis Page i Page ii Advanced Fuel & Ignition Diagnosis Diagnosis Subject Page On-Board Diagnostics Monitors Run Continously Comprehensive Component Monitor Misfire Monitor 12 Mixture Control Monitor 13 Oxygen Sensors 13 Monitors Run Once Per Key Cycle 16 Air Injection Monitors 17 Evaporative Monitor 17 Fuel Tank Ventilation Monitor 17 Fuel Tank Leak Detection Tests 19 LDP Evaporative Emissions System 21 DM-TL Fuel Tank Leak Tests 23 NVLD Natural Vacuum Leak Detection 25 Catalyst Monitor 28 Diagnostic Scheme Used Thru MY 2009 29 Additional Catalyst Monitor Schemes Used From MY 2000 Thru Till Present 31 Oxygen Monitor 35 Sensor Heater Monitor 36 Malfunction Indicator Light (MIL) 37 P-Codes 37 Generic Scan Tool 37 Advanced Fuel & Ignition Diagnosis Page 1.1 Diagnosis In this course we will examine OBD-II in detail and how the information provided by OBD-II can be used for diagnostics We will also examine how OBD-II diagnoses the engine management system and how system monitors work It is not in the scope of this course to examine all the OBDII monitors, but rather gain an in-depth understanding of what monitors are and how they work allowing us to have better insight regarding OBD-II fault paths This course should also expose the Information Media available to the technician through out the Porsche literature systems that must be examined to help supplement and support our understanding of the engine management system, onboard diagnostic capabilities, and limits On-Board Diagnostics On-Board diagnostics or OBD, is an automotive term referring to a vehicle’s self-diagnostic and reporting capability OBD systems give the technician access to state of health information for various vehicle systems and subsystems The amount of diagnostic information available via OBD has varied widely since its introduction in the early 1980s with on-board vehicle computers, which has made OBD possible Early instances of nonstandard OBD would simply illuminate a malfunction indicator light, or MIL, if a problem was detected—but would not provide any information as to the nature of the problem The concept evolved on to OBD-I a standardized monitoring system (with blink code type fault outputs through a connected warning lamp in the vehicles instrument cluster etc.), to the modern OBD-II implementations with the standardized mandatory use of a digital communications port to provide real-time data in addition to a standardized series of diagnostic trouble codes, or DTCs (and optionally proprietary manufacture specific codes) This now allows a skilled technician to rapidly identify and ideally remedy malfunctions within the vehicle quickly OBD-I The regulatory intent of OBD-I was to encourage auto manufacturers to design reliable emission control systems that remain effective for the vehicle’s “useful life” The hope was that by forcing annual emissions testing for, and denying registration to vehicles that did not pass, drivers would tend to purchase vehicles that would more reliably pass the test as a result of being emission compliant Page 1.2 OBD-I was largely unsuccessful, as the means of reporting emissions-specific diagnostic information was not standardized Technical difficulties with obtaining standardized and reliable emissions information from all vehicles led to an inability to implement the annual testing program effectively OBD-II OBD-II is an improvement over OBD-I in both capability and standardization The OBD-II standard specifies the type of diagnostic connector and its pin configuration, the electrical signaling protocols available, and the messaging format It also provides a list of vehicle parameters to monitor along with how to encode the data for each Finally, the OBD-II standard provides an extensible list of DTCs (diagnostic trouble codes) As a result of this standardization, a single device can query the on-board computer(s) in any vehicle OBD-II standardization was prompted by emissions legislation requirements, and though only emission-related codes and data are required to be transmitted through it, most manufacturers have made the OBD-II Data Link Connector the only one in the vehicle through which all systems are diagnosed and programmed Available OBD-II Diagnostic Data OBD-II provides access to data from the engine control unit (DME) and offers a valuable source of information when troubleshooting problems inside a vehicle The SAE J1979 standard defines a method for requesting various diagnostic data and a list of standard parameters that should be available from the DME The various parameters that are available are addressed by “parameter identification numbers” or PIDs which are defined in J1979 Manufacturers are not required to implement all DTCs listed in J1979 and they are allowed to include proprietary DTCs that are not listed The scan tool request and data retrieval system gives access to real time performance data as well as flagged DTCs Individual manufacturers often enhance the OBD-II code set with additional proprietary DTCs Advanced Fuel & Ignition Diagnosis Diagnosis OBD-II Diagnostic Connector The OBD-II specification provides for a standardized hardware interface—the female 16-pin (2x8) J1962 connector Unlike the OBD-I connector, which was sometimes found under the hood of the vehicle, the OBD-II connector is required to be within feet (0.61 m) of the steering wheel (unless an exemption is applied for by the manufacturer, in which case it is still somewhere within reach of the driver) SAE J1962 defines the pin configuration of the connector EOBD The EOBD (European On Board Diagnostics) regulations are the European equivalent of OBD-II, and apply to all passenger cars of category M1 (with no more than passenger seats and a Gross Vehicle Weight rating of 5500 lbs (2500 kg) or less The technical implementation of EOBD is essentially the same as OBD-II, with the same SAE J1962 diagnostic link connector and signal protocols being used Emission Testing In the United States, many states now use OBD-II testing instead of tailpipe testing in OBD-II compliant vehicles (1996 and newer) Since OBD-II stores trouble codes for emissions equipment, the testing computer can query the vehicle’s onboard computer and verify there are no emission related trouble codes and that the vehicle is in compliance with emission standards for the model year it was manufactured OBD History Timeline 1969: Volkswagen introduces the first on-board computer system with scanning capability, in their fuel-injected Type models 1975: Datsun 280Z On-board computers begin appearing on consumer vehicles, largely motivated by their need for real-time tuning of fuel injection systems Simple OBD implementations appear, though there is no standardization in what is monitored or how it is reported 1980: General Motors implements a proprietary interface and protocol for testing of the Engine Control Module (ECM) on the vehicle assembly line The “assembly line diagnostic link” (ALDL) protocol communicates at 160 baud with Pulse-width modulation (PWM) signaling and monitors very few vehicle systems Implemented on California vehicles for the 1980 model year, and the rest of the United States in 1981, the ALDL was not intended for use outside the factory The only available function for the owner is “Blink Codes” By connecting specific pins (with ignition key ON and engine OFF), the “Check Engine Light” (CEL) or “Service Engine Soon” (SES) blinks out a two-digit number that corresponds to a specific error condition Cadillac (gasoline) fuel-injected vehicles, however, are equipped with actual on-board diagnostics, providing trouble codes, actuator tests and sensor data through the new digital Electronic Climate Control display Holding down “Off” and “Warmer” for several seconds activates the diagnostic mode without need for an external scan-tool 1986: An upgraded version of the ALDL protocol appears which communicates at 8192 baud with half-duplex UART signaling This protocol is defined in GM XDE-5024B 1988: The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and set of diagnostic test signals 1991: The California Air Resources Board (CARB) requires that all new vehicles sold in California in 1991 and newer vehicles have some basic OBD capability These requirements are generally referred to as “OBD-I”, though this name is not applied until the introduction of OBD-II The data link connector and its position are not standardized, nor is the data protocol 1994: Motivated by a desire for a state-wide emissions testing program, the CARB (California Air Research Board) issues the OBD-II specification and mandates that it be adopted for all cars sold in California starting in model year 1996 (see CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094) The DTCs and connector suggested by the SAE are incorporated into this specification 1996: The OBD-II specification is made mandatory for all cars sold in the United States 2001: The European Union makes EOBD mandatory for all gasoline vehicles sold in the European Union, starting in MY 2001 (see European emission standards Directive 98/69/EC 2004: The European Union makes EOBD mandatory for all diesel vehicles sold in the European Union Advanced Fuel & Ignition Diagnosis Page 1.3 Diagnosis 2008: All cars sold in the United States are required to use the ISO 15765-4 signaling standard (a variant of the Controller Area Network (CAN) bus) 2010: HDOBD (heavy duty) specification is made mandatory for selected commercial (non-passenger car) engines sold in the United States Document Standards SAE Standards Documents on OBD-II • J1962 - Defines the physical connector used for the OBD-II interface • J1850 - Defines a serial data protocol • J1978 - Defines minimal operating standards for OBD-II scan tools • J1979 - Defines standards for diagnostic test modes • J2012 - Defines standards trouble codes and definitions • J2178-1 - Defines standards for network message header formats and physical address assignments • J2178-2 - Gives data parameter definitions • J2178-3 - Defines standards for network message frame IDs for single byte headers • J2178-4 - Defines standards for network messages with three byte headers* • J2284-3 - Defines 500K CAN Physical and Data Link Layer ISO Standards • ISO 9141: Road vehicles — Diagnostic systems International Organization for Standardization, 1989 • ISO 11898: Road vehicles — Controller area network (CAN) International Organization for Standardization, 2003 • ISO 14230: Road vehicles — Diagnostic systems — Keyword Protocol 2000, International Organization for Standardization, 1999 • ISO 15031: Communication between vehicle and external equipment for emissions-related diagnostics, International Organization for Standardization, 2010 • ISO 15765: Road vehicles — Diagnostics on Controller Area Networks (CAN) International Organization for Standardization, 2004 Notes: Page 1.4 Advanced Fuel & Ignition Diagnosis Diagnosis The following is a breakdown of the main components of the Porsche OBD-II system this will function as the outline for our examination of Porsche OBD-II Monitors Run Continuously Components of OBD-II The comprehensive component monitor (CCM) is a diagnostic program that is executed by the engine management control unit The comprehensive component monitor runs in the background and checks for open circuits, shorts to ground, shorts to power and rationality of the signals coming from the sensor circuits 1a Monitors Run Continuously I Comprehensive Component Monitor II Misfire Monitor III Mixture Control System Monitor 1b Monitors Run Once Per Key Cycle I Evaporative Emissions System Monitor a EVAP Purge Valve b Tank Leak Pressure Sensor LDP DM-TL NVLD II Air injection System Monitor III Catalyst Aging Monitor IV Oxygen Sensor Monitor V Oxygen Sensor Heater Monitor Comprehensive Component Monitor Some of the sensors that are checked by the comprehensive component monitor are: • Intake Air Temperature Sensor IATS (P0111, P0112, P0113) • Engine Coolant Temperature Sensor ECTS (P0116, P0117, P0118) • Mass Air Flow Sensor MAF (P1090, P1091, P1095, P1096, P1097, P1098) In addition, the comprehensive component monitor checks output circuits for open circuits, shorts to ground and shorts to power Malfunction Indicator Lamp & Fault Management P-Codes and Fault Identification System Generic Scan Tool Mode (CARB ISO) As we study the Porsche OBD-II system we will examine the operation of the entire Engine Management System from a diagnostic viewpoint This will be invaluable to us in our efforts to repair both MIL on and MIL off Engine Management System defects We will begin our investigation with the system monitors The output modules (final driver stages) have built in diagnostics for open shorts and internal driver malfunctions and talk directly to the processor via a digital diagnosis line Some of the outputs that are checked by the comprehensive component monitor are: • Injection valves (P0261, P0262 cylinder 1) • Fuel Pump Relay (P0230, P0231, P0232) • Intake Manifold Resonance Valve (P0660, P0661, P0662) Most of the electrical circuits connected to the engine management control unit are diagnosed by the CCM The circuits that are not checked by the CCM are monitored by their own diagnostic circuits (for example, the throttle valve control unit) that check them for electrical malfunction, or with some other diagnostic strategy, monitoring of these systems with the CCM is either not possible or not necessary In addition, some systems that have their own monitor are also monitored by the CCM for shorts and opens Advanced Fuel & Ignition Diagnosis Page 1.5 Diagnosis An example of this is the Air Injection System, it has it’s own monitor that checks it’s function, but it’s electrical circuit is checked by the CCM for shorts and opens The CCM runs from the time the key is turned on until the system shuts down Some parameters (Battery Voltage) are monitored as long as the system has power Let’s take a look at how the CCM diagnostic works on a basic sensor circuit The example we will use is the engine coolant temperature circuit Some tests that the CCM performs require the processor to remain active after the key has been turned to off For example; the processor is active for a period of time after engine is off to monitor the engine compartment temperature sensor for control of the engine compartment ventilation fan This is why the engine management relay stays energized after the key has been shut off The engine management processor also keeps track of how long the vehicle has been shut down The CCM tests the rationality of sensor circuits – rationality is whether the value of a sensor is in line with the operating conditions of the engine For example; if the engine RPM and throttle angle are low, and the air mass is very high, the air mass is not rational for that RPM and throttle angle and a fault for an implausible air mass will be stored The CCM is unique in that it performs its circuit test on the majority of circuits in the engine management system, the other monitors are focused on a specific sub-system or component Almost every component in the engine management system can have a fault code generated by the CCM The CCM runs continuously, when it has completed all of the instructions in its program, it starts over at the beginning, running in the background continuously When we examine the circuit above we see the two main elements of the analog circuit are the voltage regulator and the NTC temperature sensor The voltage regulator is needed to maintain the reference voltage of the circuit at volts This is needed to filter out voltage changes that are normal in the automotive12-volt system, the voltages in the automotive system range from approximately 9.6 volts at its lowest operational level to 14.7-or higher volts when the generator is at it’s maximum output If we did not have the regulator in the circuit, engine RPM and charging system output level would change the voltage in the circuit and the signal from the sensor would be distorted by system voltage level Also, the regulator functions as the first element in this voltage divider circuit it has to be there for the circuit to operate The second element in the analog circuit is the NTC temperature sensor – low temperature high resistance When the temperature of the engine is low, the resistance of the sensor will be high and the voltage drop across the sensor will be high at +33 F°, the voltage drop will be 4.5 volts Conversely, when the temperature of the sensor is high, the voltage drop of the sensor will be low at +210 F°, the voltage drop will be 75 volts The voltage behavior of the sensor circuit will be inverse to temperature as the temperature of the engine increases, the voltage drop of the sensor decreases This is because the resistance behavior of the sensor is inverse to temperature and the voltage drop is directly proportional to resistance Page 1.6 Advanced Fuel & Ignition Diagnosis Information Media Notes: Page 2.10 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.11 Information Media Notes: Page 2.12 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.13 Information Media Notes: Page 2.14 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.15 Information Media Notes: Page 2.16 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.17 Information Media Notes: Page 2.18 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.19 Information Media Notes: Page 2.20 Advanced Fuel & Ignition Diagnosis Information Media Notes: Advanced Fuel & Ignition Diagnosis Page 2.21 Information Media Notes: Page 2.22 Advanced Fuel & Ignition Diagnosis Part Number - PNA P25 002 ... Advanced Fuel & Ignition Diagnosis Page i Page ii Advanced Fuel & Ignition Diagnosis Diagnosis Subject Page On-Board Diagnostics... 1.4 Advanced Fuel & Ignition Diagnosis Diagnosis The following is a breakdown of the main components of the Porsche OBD-II system this will function as the outline for our examination of Porsche. .. in mass air flow measurement Notes: Page 1.10 Advanced Fuel & Ignition Diagnosis Diagnosis Air Mass Diagnosis Program Flow Chart Advanced Fuel & Ignition Diagnosis Page 1.11 Diagnosis Misfire