With the advent of electronic control systems from microprocessors in cars, the need also arose to check the operating parameters of the units themselves and the connecting electrical circuits. For this purpose, equipment was invented, called (On Board Diagnostic), initially it only provided information about the malfunction, without any clarification.
In modern cars, using an OBD connector with a standard pinout of the diagnostic connector, you can connect a special one or a scanner to the on-board computer and carry out a complete diagnosis on your own for almost any motorist. Since 1996, the second concept of the standard has been developed in the USA, which has become mandatory for newly produced cars.
Determine the purpose of OBD2:
type of diagnostic connector;
connector pinout for diagnostics;
electrical communication protocols;
message format.
The European Union has adopted EOBD, which is based on OBD2. It has been mandatory for all cars since January 2001. OBD-2 supports 5 data exchange protocols.
Knowing the location and standard pinout of the connector, you can check the car yourself. Thanks to the widespread implementation of OBD2, when diagnosing a car, you can get an error code that will be the same regardless of the make and model of the car.
The standard code contains the X1234 structure, where each character carries its own meaning:
X is the only letter symbol that allows you to recognize the faulty system (engine, gearbox, electronic components, etc.);
1 - represents the general OBD2 standard code or additional factory codes;
2 - clarification of the location of the malfunction (power or ignition system, auxiliary circuits, etc.);
34 is the serial number of the error.
The pinout of the OBD2 diagnostic connector has a special power plug from the on-board network, this allows you to use any scanners and adapters without additional electrical circuits. If earlier diagnostic protocols showed only general information about the presence of a problem, now, thanks to the connection of the diagnostic device with the electronic units of the car, more complete information about a specific malfunction can be read.
Each connected diagnostic equipment must comply with one of three international standards:
The location of the OBD2 diagnostic connector and pinout for diagnostics can vary greatly from vehicle to vehicle. There is no single standard for location; the car's operating instructions or sleight of hand will help you here.
Below are a few common points for easy reference:
- in the slot in the lower casing of the instrument panel in the area of the driver’s left knee;
- under the ashtray installed in the central part of the instrument panel (some Peugeot models);
- under plastic plugs on the bottom of the instrument panel or on the center console (typical for VAG products);
- on the rear wall of the instrument panel behind the glove box body (some Lada models);
- on the center console in the area of the parking brake lever (found on some cars
- at the bottom of the armrest niche (common on French cars);
- under the hood near the engine shield (typical of some Korean and Japanese cars).
Many motorists also sometimes intentionally move the OBD2 pinout connector to another not always standard place; this may be due to electrical wiring repairs or to protect the car from theft.
Types of connectors with pinout OBD2
In the early 2000s, there were no strict requirements for the outer shape of the connector, and many automakers assigned the device configuration themselves. There are currently two types of OBD 2 connector, referred to as Type A and Type B.
Both plugs are almost identical in appearance and have a 16-pin output (two rows of eight contacts), the only difference is between the central guide grooves.
The pins in the block are numbered from left to right, with contacts numbered 1-8 in the top row, and 9 through 16 in the bottom row. The outer part of the housing is made in the shape of a trapezoid with rounded corners, which ensures reliable connection of the diagnostic adapter. The photo shows both devices.
Connector options - Type A on the left and Type B on the right
OBD 2 connector - pinout
Below is a diagram and assignment of contacts in the OBD2 pinout connector, which are defined by the standard.
Numbering of plugs in the connector
General description of plugs:
1 - reserve, this pin can output any signal that the car manufacturer sets;
2 - channel "K" for transmitting various parameters (may be designated - bus J1850);
3 - similar to the first;
4 - grounding the connector to the car body;
5 - grounding of the diagnostic adapter signal;
6 - direct connection of the CAN bus contact J2284;
7 - channel “K” according to ISO 9141-2 standard;
8 - similar to contacts 1 and 3;
9 - similar to contacts 1 and 3;
10 - pin for connecting the J1850 standard bus;
11 - pin assignment is set by the vehicle manufacturer;
12 - similar;
13 - similar;
14 - additional pin of CAN bus J2284;
15 - channel “L” according to ISO 9141-2 standard;
16 - positive output of the on-board network voltage (12 Volts).
An example of a factory pinout of the OBD 2 connector is the Hyundai Sonata, where pin 1 receives a signal from the anti-lock braking system control unit, and pin 13 receives a signal from the control unit and airbag sensors.
Depending on the operating protocol, pinout options are allowed:
When using the standard ISO 9141-2 protocol, it is activated via pin 7, while pins 2 and 10 in the connector are inactive. For data transmission, pins numbered 4, 5, 7 and 16 are used (sometimes pin number 15 can be used).
With a protocol like SAE J1850 in the VPW (Variable Pulse Width Modulation) version, pins 2, 4, 5, and 16 are used. The connector is typical for American and European General Motors cars.
Using J1850 in PWM (Pulse Width Modulation) mode provides additional use of pin 10. This type of connector is used on Ford products. The J1850 protocol in any form is characterized by the non-use of pin number 7. Start of form
Of course, for many, such diagrams and descriptions of OBD2 connector pinouts are very complex and unnatural. Often, motorists prefer to periodically take their car to a specialized car service center and not even think about diagnostic connectors and, especially, about their pinouts. But it is still worth recognizing the usefulness of self-diagnosis. Experienced motorists say that it is necessary for every car owner to have a diagnostic scanner in their car to quickly check their doubts about the operation of the car, check for errors, settings and the like, which, first of all, will save significant money.
Obvious advantages of self-diagnosis via the OBD2 connector:
- Saving money, service stations charge a lot of money for simple computer diagnostics
- To promptly find out the error and understand the malfunction without the help of specialists, you don’t need to be nervous at the service station and you can avoid imaginary breakdowns, as often happens in unscrupulous services.
Good luck on your journey and in diagnosing your car!
Equipped with OBD2 diagnostic connectors. Using it, the car owner can connect to the control unit and find out about all possible problems that exist in the operation of certain units. You can find out what the OBD2 diagnostic connector pinout is and what the diagram looks like from this article.
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Description of OBD2 technology
The abbreviation OBD in English literally stands for diagnostics of on-board equipment. This concept is general and refers to the vehicle's self-diagnosis system. Thanks to OBD technology, the car owner can receive detailed information about the state of various car systems from the control module.
Initially, OBD technology was used to issue messages about problems in the operation of the engine and other units, but did not provide specific data. Over time, cars began to be equipped with digital connectors, which make it possible to obtain the most accurate information about malfunctions in the operation of systems. Accurate data on malfunctions are issued by error codes.
History of creation
OBD technology originates in the 50s of the last century. Then the US authorities thought about protecting the environment, since filling the continent with vehicles led to its deterioration. The technology was developed by the Society of Automotive Engineers. At first, it only allowed for monitoring the operation of the exhaust gas recirculation system, fuel supply, operation of the lambda probe, control module, etc. In general, everything that technology controlled was related to exhaust gases in one way or another.
At that time, there was no unified control system, so all automobile manufacturers used their own technologies. Several decades later, in 1996, the government created another OBD2 concept, its installation was mandatory on all vehicles. In Europe, the EOBD standard has been adopted, which is based on OBD2 technology. In the EU, this standard was introduced for all cars produced after January 2001 (video filmed by the Mr Emelya channel).
Important pinout points
The OBD2 connector pinout is a list of requirements that must be met by all vehicle manufacturers without exception. In accordance with international standards, this connector should be located no further than 18 cm from the steering wheel. This system is considered universal because it works with a standard digital protocol, with which you can obtain detailed data about problems with the car.
As for the pinout itself, the connector itself is equipped with 16 pins, the pinout is as follows:
- Determined by the vehicle manufacturer.
- This pin communicates with the J1850 bus.
- This contact is also determined by the car manufacturer.
- Monitors the grounding of vehicle contacts.
- Designed to control the grounding component of the signal line network.
- This pin is connected to the digital CAN bus.
- Communication with K-Line or ISO 9141.
- Likewise, the manufacturer sets it.
- Used to monitor the operation of the CANJ 1850 bus.
- The purpose depends on the car manufacturer.
- It is also established by companies when releasing a car.
- Determined by the car manufacturer.
- Designed to monitor the CANJ 2284 bus.
- Used to provide communication with L-line or ISO 9141-2.
- Contact associated with the car battery (video author - shlepanovan channel).
OBD2 adapter
Every modern car has this connector.
It can be connected to an adapter that can be used to perform the following functions:
- checking the condition of all systems and components of the vehicle;
- finding errors and analyzing them;
- monitoring the engine operation process as a whole;
- monitoring the voltage level in the car’s electrical network, its mileage, and engine operating temperature;
- control of fuel consumption volume, etc.
Photo gallery “Scanners for OBD2”
When buying a diagnostic scanner, you need to take into account its functional features and capabilities. To obtain more accurate data on the operating status of machine systems, you need to use more expensive adapters for testing. If you do not want to spend money on a universal device, then it is better to give preference to an adapter designed for a specific car model. Their cost will be lower, and they are initially designed to work with a specific vehicle.
The OBD2 output is used to connect the adapter with the electronic control module. Thanks to the correct pinout, the adapter is connected to the vehicle's on-board network and the device is grounded. This allows you to achieve uninterrupted operation of the device. It should also be noted that the protocols of this technology control parameters that in one way or another affect the pollution of exhaust gases, which makes it possible to protect the environment. Using the OBD output, a car enthusiast can independently test the performance of the units and systems of the car without using expensive testing equipment.
Currently, much attention is paid to monitoring the cleanliness of the environment. In this regard, OBD technology appeared, designed to make it independent. The article gives the concept, the history of creation, discusses the OBD2 pinout, and the OBDII diagram is attached.
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OBD2 Review
Most modern cars are equipped with an ECU that collects and analyzes data on the operation of various vehicle systems.
Concept and features
The term OBD - On Board Diagnostic - is a general term that refers to the self-diagnosis of a car. This technology allows you to obtain information about the status of various passenger car systems from the on-board computer.
At first, the OBD only gave a message about the malfunction, but did not provide any detailed information about its essence. The latest versions of the system use a standard digital connector, which allows you to receive information about the status of car systems in real time with the receipt of fault codes by which you can identify them. This A good device for reading errors and removing them.
An excursion into the history of creation
The history of the creation of OBD goes back to the 50s of the last century. The US government has noticed that the development of the automotive industry is worsening the environment. The specification was developed by the Society of Automotive Engineers (SAE). At first, the OBDII diagnostic system only monitored the exhaust gas recirculation system, fuel supply, oxygen sensor, and engine control unit related to exhaust gas control. There was no unified control system; each manufacturer installed its own system.
Since 1996, the second concept of the OBD2 standard has been developed in the USA, which has become mandatory for newly produced cars.
The purpose of OBD2 is to determine:
- type of diagnostic connector;
- pinout;
- electrical communication protocols;
- message format.
The European Union has adopted EOBD, which is based on OBD-II. It has been mandatory for all cars since January 2001. OBD-2 supports 5 data exchange protocols.
Pinout features
The device for working with OBD is a diagnostic connector to which devices that monitor the composition of exhaust gases and the operation of the main vehicle systems are connected. OBD2 pinout is a list of requirements that car manufacturers must adhere to.
According to the requirements, the OBD diagnostic connector must be located at a distance of no more than 18 cm from the steering wheel. The system is universal and uses the standard CAN digital protocol. It makes it possible to obtain detailed information about vehicle malfunctions.
OBD2 protocols provide the ability to read various parameters, the number of which depends on the control unit and may differ among different manufacturers (Black Mamba).
Basically about 20 parameters are supported.
Using the OBD-II system you can read:
- coolant temperature;
- in what mode does the fuel system operate;
- fuel supply correction for bank 1/2, both long-term and short-term;
- design load on the engine;
- engine speed;
- fuel pressure;
- ignition timing;
- vehicle speed;
- air flow;
- intake manifold pressure;
- throttle position;
- location of oxygen sensors and data from them;
- temperature of incoming air, etc.
To control a certain car system, 2-3 parameters are enough. But more may be required. The number of simultaneously monitored parameters and the data output format depend on the scanning device, as well as on the speed of information exchange with the computer.
The diagnostic connector has 16 contacts - their pinout is as follows:
1 – installed at the manufacturing plant;
2 – connected to the J 1850 bus (J1850 Bus+);
3- established by the manufacturer;
4- controls the grounding contacts of the vehicle (chassis) (Chassis Ground);
5 – for monitoring the signal line grounding network (Signal Ground);
6 – connected to the CAN digital bus (CAN High (J-2284));
7 - ISO 9141 - 2, K - Line;
8.9 – set by the automaker;
10 – for monitoring the CANJ 1850 bus (J1850 Bus-);
11, 12, 13 — installed by the manufacturer;
14 – for monitoring the CANJ 2284 bus (CAN Low (J-2284));
15 - ISO 9141-2, L - Line;
16 – for monitoring battery voltage (Battery Power).
Thanks to the pinout, the driver can combine his car with the OBD2 diagnostic block.
If it is determined that the exhaust gas composition does not meet the requirements, the CheckEngine inscription will light up, requiring a check of the engine operation. The indicator warns that the standard amount of harmful substances in the exhaust gases has been exceeded.
OBD2 adapter
Every car must be equipped with an OBD2 diagnostic adapter.
It is convenient to use for:
- car system diagnostics;
- error identification and analysis;
- monitoring the operation of the power unit;
- control voltage, speed, mileage, temperature;
- to track fuel consumption;
- monitoring the status of panel instruments;
- mileage tracking, etc.
When choosing a scanner, you should focus on its capabilities. Expensive devices provide more accurate diagnostics. If it is impossible to buy an expensive scanner, you should choose a scanning device made for a given car brand.
The OBD2 connector is used to connect the scanner to the ECU. Using the pinout, the scanner is connected to the vehicle's power supply and grounding, which ensures its uninterrupted operation. Thanks to OBDII protocols, parameters that affect air purity are monitored. This is environmental protection.
The presence of an OBD2 connector allows you to monitor the health of the car on your own, without resorting to expensive diagnostics.
The diagnostic connector is a standardized SAE J1962 trapezoidal connector with sixteen contacts arranged in two rows).
According to the standard, the OBD2 connector must be located inside the car (most often located in the area of the steering column). The location of the OBD-1 connector is not strictly regulated and it can even be located in the engine compartment.
Using the connector you can determine which OBD2 protocols are supported in your car. Each protocol uses specific connector pins. This information will be useful to you when choosing an adapter.
Pinout (pin assignment) of OBD2 connector
| 1 | OEM (manufacturer's protocol). |
| 2 | Bus + (Bus positive Line). SAE-J1850 PWM, SAE-1850 VPW. |
| 3 | - |
| 4 | Chassis Ground. |
| 5 | Signal Ground. |
| 6 | CAN-High line of high-speed CAN bus (ISO 15765-4, SAE-J2284). |
| 7 | K-Line (ISO 9141-2 and ISO 14230). |
| 8 | - |
| 9 | Line CAN-Low, low-speed CAN Lowspeed bus. |
| 10 | Bus - (Bus negative Line). SAE-J1850 PWM, SAE-1850 VPW. |
| 11 | - |
| 12 | - |
| 13 | - |
| 14 | CAN-Low line of high-speed CAN Highspeed bus (ISO 15765-4, SAE-J2284). |
| 15 | L-Line (ISO 9141-2 and ISO 14230). |
| 16 | Power supply +12V from the battery (Battery Power). |
Pins 3, 8, 11, 12, 13 are not defined by the standard.
Determining the OBD2 protocol used in the car
The standard regulates 5 protocols, but most often only one is used. The table will help you determine the protocol based on the contacts involved in the connector.
| Protocol | con. 2 | con. 6 | con. 7 | con. 10 | con. 14 | con. 15 |
|---|---|---|---|---|---|---|
| ISO 9141-2 | + | + | ||||
| ISO 14230 Keyword Protocol 2000 | + | + | ||||
| ISO 15765-4 CAN (Controller Area Network) | + | + | ||||
| SAE J1850 PWM | + | + | ||||
| SAE J1850 VPW | + |
In the PWM and VPW protocols there is no 7 (K-Line) pin, in ISO there is no 2 and/or 10 pin.
Currently, the overwhelming number of foreign cars, as well as domestically produced cars, have an OBD2 diagnostic connector. Through this connector you can connect diagnostic equipment to diagnose your car, as well as connect on-board computers and other devices that work through the diagnostic connector. Sometimes users have questions about the pinout of diagnostic blocks for certain car brands. For your convenience, we offer ready-made adapters for working with various diagnostic plugs on cars. However, if you forgot to purchase an adapter for your car, or you needed to make it in an emergency, or connect the adapter directly, then in this article you will find information about the pinout of OBD 2 standard blocks, as well as Russian and foreign-made cars.
Pinout of the OBD 2 block (the most common option in foreign cars since 2002, and is also installed in all VAZ cars after 2002):
Contact designations:
7-K diagnostic line
4/5 - GND protruding pins
16 - adapter power supply +12V
Pinout of the VAZ block before 2002:
Contact designations:
M - k-line diagnostics
H or G - adapter power supply +12V
When connecting an adapter without a block directly to the wires, it is better to take power from the cigarette lighter, since the contact shown in figure H, depending on the model, may not be routed, and when using the G contact, the fuel pump gives very large impulses that can damage the adapter.
(In 99% of cases, you can use the indicated contacts since damage to the adapters from the fuel pump practically does not occur.)
Connector GAZ (Gazelle) UAZ
Contact designations:
2 - Power adapter +12V
12 - mass
10 - L-diagnostic line (may not be routed, as a rule not used)
11 - K-line diagnostics
If you are interested in the location of the diagnostic block in your car, as well as the pinout of diagnostic blocks for cars of other brands. Then you can familiarize yourself with them through a systematized catalog of diagnostic adapters.
