On-board diagnostics ( OBD ) is an automotive term that refers to the automated diagnostic and reporting capabilities of a vehicle. The OBD system provides the vehicle owner or improves technician access to the status of various vehicle subsystems. The amount of diagnostic information available through OBD has varied greatly since it was introduced in early versions of the 1980s on-board vehicle computers. Initial version of OBD will only illuminate the indicator light damage or "idiot light" if the problem is detected but will not provide any information about the nature of the problem. Modern OBD implementations use standard digital communications ports to provide real-time data in addition to a series of standard troubleshooting diagnostic codes, or DTCs, which allow one to rapidly identify and correct vehicle malfunctions.
Video On-board diagnostics
History
- 1968: Volkswagen introduces the first on-board computer system with scanning capability, in a fuel injected Type 3 model.
- 1978: Datsun 280Z On-board computers are starting to appear in consumer vehicles, largely motivated by their need for real-time fuel injection system adjustment. A simple OBD implementation emerged, although there was no standardization in what was monitored or how it was reported.
- 1980: General Motors implements a special interface and protocol for testing the Machine Control Module (ECM) on the vehicle assembly line. The protocol 'assembly line diagnostic link' (ALDL) broadcasts at 160 bit/s. Implemented in California vehicles for the 1980 model, and the rest of the United States in 1981. Most owners can read the DTC (Diagnostic Trouble Code (s)) by instructing the ECM (Engine Control Module) to flash CEL (Check Engine Lights)) or MIL (Malfunction Indicator Light) is on and off. A PC-based software package called WinALDL will listen to CLCC (Closed Loop Carburetor Control) and early CLC EFI datastreams via an interface cable that is easy enough to convert 160 baud TTL serial data transmitted by ECM to RS232 or USB serial data but not much information submitted by this initial ECM.
- 1986: The latest version of the emerging ALDL protocol communicates on 8192 bit/s with half-duplex UART signaling. This protocol is defined in GM XDE-5024B.
- 1988: Society of Automotive Engineers (SAE) recommends a standard diagnostic connector and a series of diagnostic test signals.
- 1991: California Air Resources Board (CARB) requires all new vehicles sold in California in 1991 and newer vehicles have basic OBD capabilities. This requirement is commonly referred to as "OBD-I", although this name is not applied until the introduction of OBD-II. The data connecting connector and its position are not standardized, nor are the data protocols. 1994: Motivated by the desire for a statewide emission testing program, CARB issued OBD-II specifications and mandates adopted for all cars sold in California beginning in the 1996 model (see CCR Title 13 Section 1968.1 and 40 CFR Section 86 Section 86.094). DTCs and connectors recommended by SAE are incorporated into this specification.
- 1996: The OBD-II specification is made mandatory for all cars manufactured in the United States for sale in the United States.
- 2001: The EU makes EOBD compulsory for all gasoline (petrol) vehicles sold in the European Union, beginning on MY2001 (see European emission standard Directive 98/69/EC).
- 2003: The EU makes EOBD compulsory for all diesel cars sold in the EU
- 2008: All cars sold in the United States are required to use signaling standard ISO 15765-4 (variant of the Network Area Controller bus (CAN)).
- 2008: Certain light vehicles in China are required by the Office of Environmental Protection Administration to implement OBD (GB18352 standard) by 1 July 2008. Some regional exceptions may apply.
- 2010: The HDOBD (heavy duty) specifications are made mandatory for selected commercial machines (non-passenger cars) sold in the United States.
Maps On-board diagnostics
Standard interface
ALDL
GM's ALDL (Assembly Line Diagnostic Link) is a General Motors onboard diagnostic interface that began with the late 1970s and early 1980s CLCC (Closed Loop Carburetor Control) and early EFI GM systems. There is a standardization appearance because the diagnostic jack has not changed for years ALDL is used by GM. GM North America uses the Metripack 280 diagnostic jack of strategic positioning. GM Australia Holden uses 6 diagnostic diagnostic position Metripack 280. GM Europe Opel and Vauxall use 10 diagnostic diagnostic position Metripack 280. ALDL is not standard. It's actually very fragmented. The exchange of information is changed with each powertrain control module (aka PCM, ECM, ECU). (PCM integrates machine transmissions and controls on one processing unit ECM/ECU is engine control only with separate TCM (Transmission Control Module) if required.) While ALDL is the closest thing to standard onboard diagnostics before 1991 ALDL is not standard. ALDL is even split in GM brand, model, and model year. The trim levels in the same year model, division, and nameplate can use different communications. Different versions present differences in pin-out diagnostic jacks, data protocols, and data rates (this is the reason for the "Mask" files required for aftermarket software communications). The previous version used 160 bit/s, while the newer version went up to 8192 bit/s and used two way communication to PCM or ECM/TCM.
ALDL in 1991 and then the California GM emissions vehicle met with I communication standards in 1991 and later California OBD. This does not mean that ALDL is OBD I. OBD I is an early 1990s mandate in California, not a US federal mandate. It is not used on non-California emissions vehicles.
Some of the Asian, European, and North American diagnostic ports are sometimes incorrectly referred to as ALDL. A small number of vehicles manufactured before 1996 from other manufacturers using GM Delphi Electronics engines and powertrain controllers; however, it uses the modified ALDL communication protocol. Most are not and there is no homogeneous name for the diagnostic protocol and this exclusive interface port. Ford EEC, Toyota DLC, Chrysler, Nissan, Volkswagen, and others use their own onboard onboard protocols and connectors, and also not the appropriate OBD I outside California.
M-OBD
Multiplex OBD or M-OBD is OBD variant protocol used by Toyota, prior to OBD-II compliance. Toyota DLC3 (Data Link Link Connector 3) is a standard 16-pin OBD-II connector, but cables and special software are required because the generic OBD-II cable and software will not interact with it. Bus line is SIL (Pin 7)
OBD-I
A standard in 1991 and then California. This is not a US Federal standard. The purpose of the OBD-I regulation is to encourage automotive manufacturers to design reliable emissions control systems that remain effective for the vehicle's "useful life". Diagnostic Trouble Codes (DTC) from OBD-I vehicles can usually be found without expensive 'scan tools'. Each manufacturer uses a diagnostic connecting connector (DLC), DLC location, DTC definition, and a procedure for reading DTCs from vehicles. DTCs from OBD-I cars are often read through a light 'Check Engine Light' (CEL) or 'Service Engine Soon' (SES) pattern that blinks. By connecting certain pins of the diagnostic connector, the 'Check Engine' light will blur the two-digit number corresponding to a certain error condition. DTCs of some OBD-I cars are interpreted in different ways. Cadillac fuel injected vehicles (gasoline) are equipped with actual on-board diagnostics, providing problem codes, actuator testing and sensor data through the new Digital Electronic Climate Control screen. Holding 'Off' and 'Warmer' for a few seconds activates the diagnostic mode without the need for an external scan tool. Some Honda machine computers are equipped with LEDs that light up in a special pattern to show DTC. General Motors, several Ford vehicles from 1989-1995 (DCL), and several Toyota/Lexus vehicles from 1989-1995 had live sensor data streams available; However, many other vehicles equipped with OBD-I do not. OBD-I vehicles have fewer DTCs available than for vehicles equipped with OBD-II.
OBD-1.5
OBD 1.5 refers to the partial OBD-II implementation that General Motors used on several vehicles in 1994 and 1995. OBD 1.5 is a slang term. GM does not use the term OBD 1.5 in the documentation for this vehicle; they only have OBD and OBD-II sections in the service manual. Most of 1994 & amp; 1995 vehicles only 8196 baud ALDL serial data at option terminal # 9 vendor of J1962 Jack which was officially adopted for OBD II starting in 1996.
For example, Corvette 94-95 has one post-catalyst oxygen sensor (although they have two catalytic converters), and has a subset of OBD-II code that is implemented. For Corvette 1994, the OBD II code implemented is P0116-P0118, P0131-P0135, P0151-P0155, P0158, P0160-P0161, P0171-P0175, P0420, P1114-P1115, P1133, P1153 and P1158.
This hybrid system is present in GM H-body cars at 94-95, W-body cars (Buick Regal, Chevrolet Lumina ('95 only), Chevrolet Monte Carlo ('95 only), Pontiac Grand Prix, Oldsmobile Cutlass Supreme) at 94 -95, L-body (Chevrolet Beretta/Corsica) at 94-95, Y-body (Chevrolet Corvette) at 94-95, at F-body (Chevrolet Camaro and Pontiac Firebird) at 95 and at J-Body (Chevrolet Cavalier and Pontiac Sunfire) and N-Body (Buick Skylark, Oldsmobile Achieva, Pontiac Grand Am) at 95 and 96 and also on Saab '94 -'95 vehicles with naturally aspirated 2.3.
Pinouts for ALDL connections on these cars are as follows:
GM uses at least two (# 9 & amp; # 12) of what are the seven "Vendor Option" terminals (1, 8, 9, 11, 12, 13) along with # 4 Ground Chassis and # 16 Power Batteries in acceptance formally accepted J1962 Jack. Although the OBD II interface will not communicate with this controller, they will not be damaged by inserting into this jack as well. Rumors about hybrids that have ALDL GM Option # 9-Vendors & amp; GM OBD II # 2-J1850 Serial data bus terminal is populated. This author has no proof that this exists.
A scanner compatible with OBD 1.5 is required to read the code generated by OBD 1.5.
Special vehicle diagnostic and control circuits are also available on this connector. For example, in Corvette there is an interface for Class 2 serial data stream from PCM, CCM diagnostic terminal, radio data stream, airbag system, selective ride control system, low tire pressure warning system, and passive keyless entry system.
An OBD 1.5 has also been used on Mitsubishi '95 '97 vintage cars, some 1995 Volkswagen VR6 and at Ford Scorpio since 95.
The captured code is still a 2 digit code that still requires ALDL scanning tools, laptops and USB-ALDL interfaces with a properly embedded J1962 ALDL plug, or GM Tech II. Flash codes can be taken on the 1994-1995 Corvette by shortening Option # 12-Vendor to # 4 Chassis Ground.
OBD-II
OBD-II is an improvement over OBD-I in both capability and standardization. The OBD-II standard determines the type of diagnostic and pinout connectors, available electrical signaling protocols, and message delivery formats. It also provides a list of potential vehicle parameters to monitor along with how to encode the data for each. There is a pin on the connector that provides power to the scan device of the vehicle battery, which eliminates the need to connect the scan device to the power source separately. However, some technicians may still connect the scan tool to additional resources to protect data in the unusual event that the vehicle is losing power due to malfunction. Finally, the OBD-II standard provides a list of standard DTCs. As a result of this standardization, one device may request an on-board computer for this parameter in any vehicle. The OBD-II standardization is required to simplify the diagnosis of increasingly complex emission equipment, and even if only emissions-related codes and data are required to be transmitted through US law, most manufacturers have made OBD-II Data Link Connectors the primary connector. in a vehicle where all systems are diagnosed and re-programmed. The OBD-II Diagnostic Issue Code is a 4-digit, beginning with the letter: P for engine and transmission (powertrain), B for body, C for chassis, and U for network. Manufacturers can also add custom data parameters to their specific OBD-II implementation, including real-time data requests as well as problem codes.
OBD-II diagnostic connector
The SAE J1962 specification provides two standard hardware interfaces, called type A and type B . Both are women, 16-pin (2x8), D-shaped connectors, and both have a groove between two pin lines, but the B-type groove is interrupted in the middle. This prevents the insertion of type A male plug into a B type female socket while allowing male Type B plugs to be inserted into a Type A female socket.
Type A connectors are used for vehicles using a 12V supply voltage, while type B is used for 24V vehicles and is required to mark the front of the D-shaped area in blue.
SAE J1962 defines pinout connector as:
Unlike the OBD-I connector, which is sometimes found under the hood, the OBD-II connector is required to be within 2 feet (0.61 m) of the steering wheel (unless an exception is applied by the manufacturer, in this case it is still somewhere within range of driver).
EOBD
The EOBD Regulations (Europe on the diagnostic board) are the European equivalent of OBD-II, and are applicable to all passenger cars of the M1 category (with no more than 8 passenger seats and a Gross Vehicle Weight rating of 2500 kg or less) first registered in EU Member States since 1 January 2001 for gasoline (petrol) cars and from 1 January 2004 for diesel-engined cars.
For the newly introduced model, the date the regulations were applied a year earlier - January 1, 2000 for gasoline and January 1, 2003 for diesel.
For passenger cars rated Gross Vehicle Weight is greater than 2500 kg and for light commercial vehicles, the date of the applicable regulations from 1 January 2002 for gasoline models, and January 1, 2007 for diesel models.
The technical implementation of EOBD is essentially the same as OBD-II, with SAE J1962 link diagnostic connector and signal protocol being used.
By 2017, all previous standards are revoked because there are more than 24 standards produced for 35 years. The new document completes all previous versions.
EOBD error code
Each EOBD error code consists of five characters: a letter, followed by four numbers. The letter refers to the system being interrogated eg Pxxxx will refer to the powertrain system. The next character is 0 if it matches the EOBD standard. So it should look like P0xxx.
The next character will refer to the sub system.
- P00xx - Fuel and air gauges and additional emission controls.
- P01xx - Fuel and air meters.
- P02xx - Fuel and air meters (injector circuit).
- P03xx - Ignition or jam system.
- P04xx - Additional emission controls.
- P05xx - Vehicle speed control and idle control system.
- P06xx - Computer output.
- P07xx - Transmission.
- P08xx - Transmission.
The following two characters will refer to individual errors in each subsystem.
EOBD2
The term "EOBD2" is a marketing language used by some vehicle manufacturers to refer to manufacturer-specific features that are not actually part of OBD or EOBD standards. In this case "E" stands for Enhanced.
JOBD
JOBD is an OBD-II version for vehicles sold in Japan.
ADR 79/01 & amp; ; 79/02 (Australian OBD Standard)
ADR Standard Standard 79/01 (Australian Design Rule 79/01 - Emissions Control for Light Vehicles, 2005) is equivalent to OBD-II in Australia. This applies to all vehicles of the M1 and N1 categories with a gross weight rating of 3500 kg or less, registered from new in Australia and manufactured from 1 January 2006 for gasoline and from 1 January 2007 for diesel engined engines. For the newly introduced model, the regulatory dates were applied a year earlier - January 1, 2005 for gasoline and January 1, 2006 for diesel. Standard ADR 79/01 is equipped with ADR 79/02 standard which imposes stricter emission restrictions, applies to all M1 and N1 class vehicles with gross vehicle weight 3500 kg or less, from 1 July 2008 for new model, July 1, 2010 to all models. The technical implementation of this standard is essentially the same as the OBD-II, with the same SAE J1962 diagnostic link connector and signal protocol used.
OBD-II signal protocol
Five signaling protocols are allowed with the OBD-II interface; most vehicles only apply one. It is often possible to infer protocols, based on existing pins on the J1962 connector:
- SAE J1850 PWM (pulse width modulation - 41.6 kbit/s, Ford Motor Company standard)
- pin 2: Bus
- pin 10: Bus -
- High voltage 5Ã, V
- Message length is limited to 12 bytes, including CRC
- Using a multi-master arbitration scheme called 'Multi -ense Access to Mastery with Non-Destructive Arbitration' (CSMA/NDA)
- SAE J1850 VPW (variable pulse width - 10.4 kbit/s, General Motors standard)
- pin 2: Bus
- An empty bus under
- High voltage 7Ã, V
- The decision point is 3.5Ã, V
- Message length is limited to 12 bytes, including CRC
- Using CSMA/NDA
- ISO 9141-2. This protocol has an asynchronous serial data rate of 10.4 kbit/s. This is somewhat similar to RS-232; however, the signal levels are different, and communication occurs on one, two-way channel without additional handshake signals. ISO 9141-2 is mainly used on Chrysler, European and Asian vehicles.
- pin 7: K-line
- pin 15: L-line (optional)
- UART signaling
- K-line idle high, with 510 ohm resistor to V batt
- Active/dominant status is pushed low with open collector drivers.
- The message length is Max 260Bytes. Data field MAX 255.
- ISO 14230 KWP2000 (Keyword Protocol 2000)
- pin 7: K-line
- pin 15: L-line (optional)
- The physical layer is identical to ISO 9141-2
- Data rate 1.2 to 10.4 kbit/s
- High signal voltage level: 12V (min/max 9.60 to 13.5)
- Messages can contain up to 255 bytes in the data field
- ISO 15765 CAN (250 kbit/s or 500 kbit/s)). The CAN protocol was developed by Bosch for automotive and industrial control. Unlike other OBD protocols, variants are widely used outside of the automotive industry. Although it did not meet OBD-II requirements for US vehicles prior to 2003, in 2008 all vehicles sold in the US were required to apply CAN as one of their signing protocols.
- pin 6: CAN High
- pin 14: CAN Low
- CANC signal voltage level: 3.5V (min/max 2.75 to 4.50)
- Signal voltage level of CANL: 1.5V (min/max 0.5 to 2.25)
All OBD-II pinouts use the same connector, but different pins are used with the exception of pin 4 (battery ground) and pin 16 (positive battery).
The OBD-II diagnostic data is available
OBD-II provides access to data from the machine control unit (ECU) and offers valuable source of information when solving problems in the vehicle. The SAE J1979 standard defines a method for requesting various diagnostic data and a list of standard parameters that may be available from the ECU. The various parameters available are handled by the "parameter identification number" (parameter ID or PID) defined in J1979. For a list of basic PIDs, their definitions, and formulas for converting raw OBD-II output to meaningful diagnostic units, see OBD-II PID. Manufacturers are not required to apply all PIDs registered in J1979 and they are permitted to enter exclusive unlisted PIDs. PID requests and data retrieval systems provide access to real time performance data and marked DTCs. For a list of generic OBD-II DTCs suggested by SAE, see OBD-II Code Table. Individual producers often upgrade the OBD-II code set with additional proprietary DTCs.
Operation mode
The following is a basic introduction to the OBD communication protocol in accordance with ISO 15031:
- Mode $ 01 is used to identify what powertrain information is available for the scan tool.
- Mode $ 02 displays Freeze Frame data.
- Mode $ 03 lists the "confirmation" diagnostic diagnostic code regarding stored emissions. It displays the exact number, the 4 digit code that identifies the error.
- Mode $ 04 is used to clean emission-related diagnostic information. This includes clearing stored DTC and Freeze Frame data.
- Mode $ 05 displays an oxygen sensor monitor screen and test results are collected about oxygen sensors. There are ten numbers available for diagnostics:
- $ 01 O2 Rich-to-Lean sensor voltage ratio
- $ 02 Lean-to-Rich O2 sensor threshold voltage
- $ 03 Low sensor voltage threshold for switch time measurement
- $ 04 High sensor voltage threshold for moving time measurement
- $ 05 Time switching Rich-to-Lean in ms
- $ 06 Lean-to-Rich time in min
- $ 07 Minimum voltage for testing
- $ 08 Maximum voltage for testing
- $ 09 Time between transition voltages in ms
- Mode $ 06 is a request for on-board monitoring test results for continuously monitored and non-continuous systems. There is usually a minimum value, a maximum value, and a current value for each non-continuous monitor.
- Mode $ 07 is a request for an emission diagnostic issue code that was detected during the current or last completed driving cycle. This allows external testing tools to obtain diagnostic diagnostic code "pending" detected during the current or final completed driving cycle for emission-related components/systems. These are used by service technicians after vehicle repair, and after cleaning diagnostic information to see the test results after one driving cycle to determine whether the fix has fixed the problem.
- Mode $ 08 may enable the off-board test device to control the operation of the system, test, or components inside the aircraft.
- Mode $ 09 is used to retrieve vehicle information. Among others, the following information is available:
- VIN (Vehicle Identification Number): Vehicle ID
- CALID (calibration identification): ID for software installed on ECU
- CVN (calibration verification number): The number used to verify the integrity of the vehicle software. The manufacturer is responsible for determining the method of calculating CVN (s), e.g. using checksum.
- The performance counters used
- Gasoline engine: catalyst, primary oxygen sensor, evaporator system, EGR system, VVT system, secondary air system and secondary oxygen sensor
- Diesel engines: NMHC catalysts, NOx reduction catalysts, particulate NOx absorber filters, flue gas sensors, EGR systems, VVT systems, push-up controls, fuel systems.
- Mode $ 0A lists the "permanent" diagnostic diagnostic code associated with its stored emissions. As per CARB, any diagnostic issue code that instructs MIL on and is stored into non-volatile memory should be recorded as a permanent damage code.
OBD app
Various tools are available that are plugged into the OBD connector to access OBD functions. These range from simple generic consumer level tools to highly sophisticated OEM dealer tools to vehicle telematic devices.
Mobile scanning tool
Various rugged hand scan tools are available.
- The code reader/simple code reset tool is mostly intended for the consumer level.
- Professional handheld scanners may have more sophisticated functionality
- Advanced diagnostic access
- Specify manufacturer or vehicle-specific ECU parameters
- Access and control other control units, such as airbags or ABS
- Real-time monitoring or engine parameter charts for easy diagnosis or adjustment
Mobile device-based tools and analysis
Mobile device apps allow mobile devices like phones and tablets to view and manipulate OBD-II data accessed via a USB adapter cable, bluetooth or WiFi adapter plugged into the OBD II car connector. A number of new devices allow vehicle OBD ports to stream data directly to the Internet via cellular connections.
scan tools and PC-based analysis platform
PC-based OBD analysis tool that converts the OBD-II signal into serial data (USB or serial port) standard to PC or Mac. The software then translates the received data to the visual display. Many popular interfaces are based on ELM or STN11x0 OBD Interpreter ICs, both read all five generic OBD-II protocols. Some adapters now use the J2534 API that allows them to access the OBD-II Protocol for cars and trucks.
In addition to the functionality of the handheld scan tool, PC-based tools generally offer:
- Large storage capacity for data recording and other functions
- The resolution screen is higher than the handheld
- The ability to use multiple software programs adds flexibility
The extent to which PC tools can access the manufacturer or diagnostic of a vehicle's specific ECU varies between software products as it does between the handheld scanner.
Data recorder
The data recorder is designed to capture vehicle data when the vehicle is in normal operation, for later analysis.
Use of data logging includes:
- Monitoring of engines and vehicles under normal operation, for diagnostic or tuning purposes.
- Some car insurance companies offer premium deductions if OBD-II data of the faller or camera vehicle is installed - and if the driver's behavior meets the requirements. This is a form of auto insurance risk selection
- Monitor driver behavior by fleet vehicle operators.
Analysis of vehicle black box data may be made periodically, automatically transmitted wirelessly to third parties or taken for forensic analysis after an event such as an accident, a traffic violation or a mechanical error.
Emissions test
In the United States, many states now use OBD-II testing rather than exhaust testing on appropriate vehicles OBD-II (1996 and later). Because the OBD-II stores the problem code for the emissions equipment, the test computer can ask the vehicle's onboard computer and verify that there is no emission-related issue code and that the vehicle complies with emission standards for the model year.
In the Netherlands, 2006 and later vehicles are subject to annual EOBD emissions checks.
Additional driver vehicle instrument
The vehicle driver's supplementary instrument is installed in a vehicle other than that provided by the vehicle manufacturer and is intended to be shown to the driver during normal operation. This is contrary to the scanner used primarily for the diagnosis of active errors, tuning, or recording of hidden data.
Automotive fans have traditionally installed additional gauges such as vacuum manifolds, battery currents, etc. The OBD standard interface has enabled a whole new generation of enthusiastic instrumentation to access various vehicle data used for diagnostics, and derived data such as instantaneous fuel economy.
Instrumentation can be a special travel computer, carputer or interface for a PDA, smartphone, or GPS navigation unit.
As the carputer is basically a PC, the same software can be loaded for PC based scan tools and vice versa, so the difference is only in the reasons for using the software.
This enthusiast system may also include some functions similar to other scan tools.
Vehicle telematics
OBD II is no longer only used by professionals and fans to improve the vehicle. OBD II information is generally used by vehicle telematics devices that perform fleet tracking, monitor fuel efficiency, prevent unsafe driving, as well as for remote diagnostics and with pay-as-you-drive insurance. Although originally not intended for the above purposes, generally-backed OBD II data such as vehicle speed, RPM, and fuel levels enable GPS-based fleet tracking devices to monitor vehicle idling times, accelerate, and reverse excessively. By monitoring the OBD II DTC a company can know immediately if one of its vehicles has a machine problem and by interpreting the code of the nature of the problem. OBD II is also monitored to block mobile phones while driving and to record travel data for insurance purposes.
Standard document
SAE standard document in OBD-II
- J1962 - Specifies the physical connectors used for the OBD-II interface.
- J1850 - Defines a serial data protocol. There are two variants - 10.4 kbit/s (single cable, VPW) and 41.6 kbit/s (two wires, PWM). Mainly used by US manufacturers, also known as PCI (Chrysler, 10.4 kbit/s), Class 2 (GM, 10.4 kbit/s), and SCP (Ford, 41.6 kbit/s)
- J1978 - Defines minimum operating standards for the OBD-II scanner
- J1979 - Set the default for diagnostic test mode
- J2012 - Defines the default problem codes and definitions.
- J2178-1 - Specifies standards for the format of network message headers and physical address assignments
- J2178-2 - Provides the data parameter definition
- J2178-3 - Specifies the default for the network template message ID for single byte headers
- J2178-4 - Specifies the default for network messages with three byte headers *
- J2284-3 - Determining 500Ã, kbit/dt CAN Physical Link Layers and Data
- J2411 - Describes the GMLAN (one-wire CAN) protocol, used in newer GM vehicles. Often accessed in OBD connector as PIN 1 on newer GM vehicles.
SAE standard document on HD (heavy duty) OBD
- J1939 - Defines data protocols for heavy commercial vehicles
ISO standard
- ISO 8093: Road vehicle - Electronic system diagnostic test
- ISO 9141: Vehicle - Diagnostic system. International Organization for Standardization, 1989.
- Part 1: Requirements for digital information exchange
- Part 2: CARB Terms for digital information exchange
- Part 3: Verify communication between the vehicle and the OBD II scanner
- ISO 11898: Road vehicle - Network area control (CAN). International Organization for Standardization, 2003.
- Part 1: Data link and physical signaling layer
- Part 2: High-speed media access unit
- Part 3: A low-speed, fault-tolerant, and intermediate-dependent interface
- Part 4: Time-triggered communication
- ISO 14230: Vehicle - Diagnostic System - Keyword Protocol 2000, International Organization for Standardization, 1999.
- Part 1: Physical layer
- Part 2: Data link layer
- Part 3: Application layer
- Part 4: Requirements for emission-related systems
- ISO 14320 no data
- ISO 15031: Communication between vehicles and external equipment for emissions-related diagnostics, International Organization for Standardization, 2010.
- Part 1: General information and use case definitions
- Part 2: Guides on terms, definitions, abbreviations and acronyms
- Part 3: Diagnostic connectors and related electrical circuits, specifications and usage
- Part 4: External test equipment
- Part 5: Diagnostic services related to emissions
- Part 6: Diagnostic problem code definitions
- Part 7: Data link security
- ISO 15765: Road vehicle - Diagnostic on the Network Control Area (CAN). International Organization for Standardization, 2004.
- Part 1: General information
- Part 2: Network layer services ISO 15765-2
- Part 3: Implement an integrated diagnostic service (UDS on CAN)
- Part 4: Requirements for emission-related systems
Security issues
Researchers at the University of Washington and the University of California examined the safety around the OBD, and found that they were able to control many vehicle components through the interface. Furthermore, they can upload new firmware into the machine control unit. Their conclusion is that the vehicle embedded system is not designed with security in mind.
There are reports of thieves using OBD specialist reprogramming tools to allow them to steal cars without using a key. The main cause of this vulnerability lies in the tendency of vehicle manufacturers to extend buses for purposes other than those designed, and the lack of authentication and authorization in the OBD specification, which in turn depends heavily on security through obscurity. The National Highway Traffic Safety Administration has demonstrated the ability to take over certain functions via cable to the car control center.
In 2012, vehicles manufactured by BMW, Porsche, Opel, Renault, Mercedes, Volkswagen, and Toyota were stolen by programming an empty key fob to start the car through an OBD connection. BMW offers to all free repair owners through software updates, and all newer vehicles have improved software that fixes this vulnerability.
See also
- OBD-II PIDs ("Parameter ID")
- Machine control unit
- Immobilizer
- ELM327 integrated circuits are very common inside scan tool
- OBDuino onboard computer built with Arduino which has the tool scan function
- Scanning tool (automotive) scan tool that can connect to DLC
- Data connector connector (automotive) Standard Data Link Connector
- The bus was originally for the multiplex electric cable in the car, but also used in many other contexts
- Vehicle bus special internal communications network that connects components in the vehicle
References
- Notes
External links
- Directive 98/69/EC of the European Parliament and of the Council of 13 October 1998
- National OBD Center Clearing Center for Automotive Science and Technology at Weber State University
- United States OBD Environmental Protection Agency Information for repair technicians, vehicle owners, and manufacturers
- OBD2 Vehicle Pinout plug includes a specific OBD-II Diagnostic Manufacturer's compatibility list and compatibility information.
- Is My Car OBD2 Compatible and Supported by OBD Scanner/Software? Is My Car OBD2 Compatible and Supported by OBD Scanner/Software?
Source of the article : Wikipedia
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