OBD2 diagnostic connector: pinout, where it is located, how to connect it and decipher error codes. What is the OBD2 diagnostic connector pinout: what does the OBD connector circuit look like?
Over time, appearing in cars electronic systems control from microprocessors, there was also a need 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 diagnostic connector pinout, 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;
pinout of the connector 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 previously diagnostic protocols showed only general information about the presence of any problem, now, thanks to the connection of the diagnostic device with electronic units car can be viewed more complete information about a specific malfunction.
Each connected diagnostic equipment must comply with one of three international standards:
The location of the diagnostic connector with OBD2 pinout for diagnostics may vary greatly depending on the various cars. 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 near the lever parking brake(found on some machines
- in the lower part 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 OBD2 pinouts
In the early 2000s, there were no strict requirements for the outer shape of the connector, and many automakers assigned the device configuration themselves. Today, there are two types of OBD 2 connector, designated 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 versions of the devices.
Connector types - 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 (can be designated as J1850 bus);
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 control unit anti-lock braking system, and on pin 13 - 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 may 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!
Currently, the overwhelming number of foreign cars, as well as cars domestic production have 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.
OBD diagnostic connector
In this article I will try to introduce you to the principles of operation of an injection engine from the electrical circuit side. There is an opinion that the carburetor is simple, reliable and unpretentious, and the injector... There is no better way to say “Injector...”. My personal opinion is that you shouldn’t listen to such experts. You just need to understand the issue.
In order to understand what the car “breathes” there is a diagnostic connector. The appearance he has now did not appear immediately. As always, America helped us with this. We know that they are going crazy, but the fact that something good comes out of it is quite a rare case. However, first things first. For a very long time, the US government supported its automobile industry (not to be confused with what is happening in Russia). But then environmentalists sounded the alarm, the same ones who are against warming up cars, they say, your cars are spoiling the environment. Commissions, committees and subcommittees, decrees began to be created... the producers pretended to obey, but in fact they neglected everything they could. And then the energy crisis struck, which led to a decline in production, automakers became thoughtful, and it became unprofitable to ignore government decisions. It was in such a difficult situation that the OBD (On Board Diagnostics) rules were created www.obdii.com for those who speak English). Each manufacturer used its own emission control methods. To change this, the Association of Automotive Engineers proposed several standards, and it is believed that the birth of OBD occurred when the Department of Air Control made many of these standards mandatory in California for vehicles starting in 1988. Only a few parameters were monitored: an oxygen sensor, an exhaust recirculation system, a fuel supply system and an engine control unit in terms of exceeding exhaust gas standards. But it was not possible to restore order in this way, but only made everything even more confusing. Firstly, monitoring systems were literally far-fetched for older cars, since they were created as additional equipment. Manufacturers only formally fulfilled the requirements, the cost of the car increased. Secondly, independent services began to howl - each car became almost unique, it required detailed manufacturer’s instructions, a description of the codes, and a scanner with its own connector. The US government was to blame; it was accused by manufacturers, environmentalists, service stations, and car enthusiasts. In 1996, it was decided that all automobile manufacturers selling their products in the United States must adhere to OBDII standards, a revised OBD specification. Thus, OBDII is not an engine management system, as many believe, but a set of rules and requirements that each manufacturer must comply with in order to comply with US federal regulations on composition exhaust gases. For a deeper understanding, I propose to consider in more detail the main requirements of the standard.
1. OBDII standard diagnostic connector. Its main function is to enable the diagnostic scanner to communicate with control units that are OBDII compliant and comply with SAE J1962 standards, i.e. it must be located in one of the eight locations defined by the Protection Agency environment(wow!!!) and within 16 inches of the steering column. Each contact has its own purpose, some, for example, are at the discretion of the manufacturer, the main thing is that they do not interfere with OBDII-compatible control units.
Let's take a closer look at the connectors. Connectors 4, 5, 16 relate to power supply, this is done for reasons of convenience - the scanner is immediately supplied with power supply, no separate wire is required, for example to the cigarette lighter. 2, 10, 6, 14, 7,15 are the actual conclusions of three equivalent standards. Manufacturers can choose which one to use for their products. Thus, from the point of view of the connector and protocols, there is complete unification.
Fig2 
This is how Hyundai disposed of the diagnostic connector. Please note that the connector numbers in the pictures do not match, as the block and plug are shown.
2. Standard communication protocols for diagnostics. As you can see, the standard provides only three protocols. The operating algorithm is simple “request-response”. The protocols themselves are also classified by data exchange speed.
A- the slowest 10 KB/s. The ISO9141 standard uses a Class A protocol.
B- speed 100 Kb/s. This is SAE J1850 standard.
WITH- speed 1 MB/s. The most used Class C standard for automobiles is the CAN protocol.
Let's look at these protocols...
J1850 protocol. There are two types: J1850 PWM((Pulse Width Modulation - pulse width modulation) high speed, providing 41.6 KB/sec. It is used by Ford, Jaguar and Mazda. In accordance with the PWM protocol, signals are transmitted over two wires to pins 2 and 10. J1850 VPW (Variable Pulse Width- variable pulse width) supports data transfer at 10.4 speed. Kbytes/sec. It's being used General Motors(GM) and Chrysler. This protocol uses one wire and uses connector 2. ISO 9141 not as complicated as J1850, does not require communication microprocessors. Used in most European and Asian cars, as well as some Chrysler models.
Here I would like to make a small digression for the owners Hyundai cars. Please note that we have 2 contacts involved (protocol ISO 9141), none other than the well-known K-Line. And this opens up wide opportunities for the use of BCs made for VAZ cars. After all, what the creators of OBDII sought was compatibility, and this is what you will get. There is one nuance, but more on it later.
3. Check Engine fault indicator light. It lights up when the engine management system detects a problem with the composition of the exhaust gases. Its purpose is to inform the driver that a problem has arisen during the operation of the engine control system. It should be interpreted as follows “It would be nice to stop by the service center” that's all. The engine will not explode, the car will not catch fire. It's another matter if your oil light or engine overheat warning comes on. Then you need to panic. The Check Engine light is triggered according to a specific algorithm, depending on the severity of the malfunction. If the malfunction is serious and urgent repairs are required, the indicator lights up immediately. This type of fault is classified as Active. If the error is not fatal, the indicator does not light up, and the fault is assigned a stored status (Stored). In order for such a fault to become active, it must repeat itself over several drive cycles (this is the process by which a cold engine starts and runs until operating temperature is reached).
4. Diagnostic Trouble Codes (DTC - Diagnostic Trouble Code). The malfunction in the OBDII standard according to the J2012 specification is described as follows:
fig3 
First character indicates in which part of the vehicle a malfunction is detected. The choice of symbol is determined by the control unit being diagnosed. If a response is received from two blocks, the letter for the block with higher priority is used.
P- engine and transmission
B- body
C- chassis
U- network communications
The second character shows what the code has identified.
0 or P0- basic (open) fault code defined by the Association of Automotive Engineers.
1 or P1- fault code determined by the vehicle manufacturer.
But not everything is as smooth in the Danish kingdom as it seems at first glance. Remember, I promised to tell you about one nuance. So, almost all bookmakers know the P0 codes - the basic ones, but the internal ones are different for each car. For example, Accent has its own unique error codes for each model year, but on Matrix - no, why this happened is a mystery to me.
The third character is the system in which a malfunction has been detected. It carries the most useful information.
1 - fuel-air system
2 - fuel system
3 - ignition system
4 - auxiliary emission control system (exhaust gas recirculation valve, manifold air intake system, catalytic converter or fuel tank ventilation system)
5 - speed control or idle control system with corresponding auxiliary systems
6 - engine control module
7
8 - transmission or drive axle
Fourth and fifth characters This is an individual error code. These usually correspond to older OBDI codes.
5. Self-diagnosis of malfunctions leading to increased toxicity of emissions. Engine control software is a set of OBDII-compatible programs that run in the engine control unit and monitor everything that's going on around it. The engine control unit is a real computer. During the operation of which a huge number of calculations are performed for commands by numerous engine devices, based on data received from various sensors. In addition to this, the controller must diagnose and manage OBDII system components, namely:
Check drive cycles that determine the generation of error codes
Starts and executes component monitors
Defines the priority of monitors
Updates the readiness status of monitors
Outputs test results for monitors
Avoids conflicts between monitors
The monitor is a test performed by the OBDII system in the engine control unit to evaluate the correct functioning of the emission components. There are two types of monitors:
Continuous (executed as long as appropriate conditions exist)
Discrete (triggered once per trip)
There is one more issue that needs to be considered separately - on-board computers (BC). Just don’t confuse it with a craft from Amigo or a regular one - they practically do not contain useful information. What are real bookmakers for and what can they do? There are a lot of people who just like to tinker with their car, to know how it “lives.” Sometimes you can simply save money - for example, you determine which sensor is faulty, buy it yourself, change it yourself. After all, the service center will definitely include diagnostics in the bill, and will sell the sensor at an incredible markup. For example, I very often come to the service center with a ready-made solution - I’m interested in solving the problem, but not in turning the nuts. I’m interested in what the instantaneous consumption is, how the network voltage jumps from consumers, what parameters are produced by the sensors, what errors in operation were recorded. This is a hobby. And I understand perfectly why manufacturers not only do not supply full-fledged BCs, but also do not certify them from third-party manufacturers. We are depriving dealers of super profits. The formal pretext is the extra load on the engine control unit, they say it is forced to process more BC requests. Of course, there is logic in such a statement, but excuse me, what about the scanners at dealers, why don’t they load them? They are loaded, but they are certified. And they cost incredible amounts of money. Some kind of vicious circle. In general, draw your own conclusions. I hope that with the help of this article you are closer to understanding your car.
All modern cars, especially after 1996, include a diagnostic system using a universal protocol OBD- OBD-II. These devices can be built on a computer with an interface that connects to a 16-pin diagnostic connector. Diagnostics and self-testing in OBD 2 systems is carried out by a subroutine called Diagnostic Executive. The subroutine, using special monitors, controls several different car systems, a malfunction of which can lead to an increase in toxic emissions. The subroutine is executed in background- at the time when on-board computer not engaged in performing basic management functions.
Error codes include categories:
"P" - is for powertrain codes; "B" - is for body codes;
"C" - is for chassis codes.
The category is indicated in the first position of the five-digit error code. The second position in this code indicates the standard, where “0” is a common code for OBD-II or “1” if it is a manufacturer’s code. Third position - type of malfunction:
“1” and “2” - malfunctions in the fuel system or air supply;
"3" - problems in the ignition system;
"4" - for auxiliary emission control;
"5" - problems idle speed;
"6" - malfunction of the controller or its output circuits;
"7" and "8" - transmission malfunctions.
List of OBD Error Codes
P0 1XX FUEL AND AIR METERING Fuel and air metersPO 100 MAF or VAF CIRCUIT MALFUNCTION Air Flow Sensor Circuit Malfunction
PO 101 MAF or VAF CIRCUIT RANGE/PERF PROBLEM Signal out of range
PO 102 MAF or VAF CIRCUIT LOW INPUT Low level output signal
PO 103 MAF or VAF CIRCUIT HIGH INPUT High level output signal
PO 105 MAP/BARO CIRCUIT MALFUNCTION Air pressure sensor malfunction
PO 106 MAP/BARO CIRCUIT RANGE/PERF PROBLEM Signal out of range
PO 107 MAP/BARO CIRCUIT LOW INPUT Low output level
PO 108 MAP/BARO CIRCUIT HIGH INPUT High output level
PO 110 IAT CIRCUIT MALFUNCTION Intake air temperature sensor malfunction
PO 111 IAT RANGE/PERF PROBLEM Signal out of range
PO 112 IAT CIRCUIT LOW INPUT Low output signal level
PO 113 IAT CIRCUIT HIGH INPUT High output level
PO 115 ECT CIRCUIT MALFUNCTION Coolant temperature sensor malfunction
PO 116 ECT RANGE/PERF PROBLEM Signal out of range
PO 117 ECT CIRCUIT LOW INPUT Low output level
PO 118 ECT CIRCUIT HIGH INPUT High output level
PO 120 TPS SENSOR A CIRCUIT MALFUNCTION Throttle position sensor malfunction
PO 121 TPS SENSOR A RANGE/PERF PROBLEM Signal out of range
PO 122 TPS SENS A CIRCUIT LOW INPUT Low output level
PO 123 TPS SENS A CIRCUIT HIGH INPUT High output level
PO 125 LOW ECT FOR CLOSED LOOP FUEL CONTROL Low temperature cooling fluid for closed loop control
PO 130 02 SENSOR B1 S1 MALFUNCTION O2 sensor B1 S1 is faulty (Bank1)
PO 131 02 SENSOR B1 S1 LOW VOLTAGE O2 sensor B1 S1 has a low signal level
PO 132 02 SENSOR B1 S1 HIGH VOLTAGE O2 sensor B1 S1 has a high signal level
PO 133 02 SENSOR B1 S1 SLOW RESPONSE O2 sensor B1 S1 has a slow response to enrichment/depletion
PO 134 02 SENSOR B1 S1 CIRCUIT INACTIVE O2 sensor circuit B1 S1 passive
PO 135 02 SENSOR B1 S1 HEATER MALFUNCTION O2 sensor heater B1 S1 is faulty
PO 136 02 SENSOR B1 S2 MALFUNCTION O2 sensor B1 S2 is faulty
PO 137 02 SENSOR B1 S2 LOW VOLTAGE O2 sensor B1 S2 has a low signal level
PO 138 02 SENSOR B1 S2 HIGH VOLTAGE O2 sensor B1 S2 has a high signal level
PO 139 02 SENSOR B1 S2 SLOW RESPONSE O2 sensor B1 S2 has a slow response to enrichment/depletion
PO 140 02 SENSOR B1 S2 CIRCUIT INACTIVE O2 sensor circuit B1 S2 passive
PO 141 02 SENSOR B1 S2 HEATER MALFUNCTION O2 sensor heater B1 S2 is faulty
PO 142 02 SENSOR B1 S3 MALFUNCTION O2 sensor B1 S3 is faulty
PO 143 02 SENSOR B1 S3 LOW VOLTAGE O2 sensor B1 S3 has a low signal level
PO 144 02 SENSOR B1 S3 HIGH VOLTAGE O2 sensor B1 S3 has a high signal level
PO 145 02 SENSOR B1 S3 SLOW RESPONSE O2 sensor B1 S3 has a slow response to enrichment/depletion
PO 146 02 SENSOR B1 S3 CIRCUIT INACTIVE O2 sensor circuit B1 S3 is passive
PO 147 02 SENSOR B1 S3 HEATER MALFUNCTION O2 sensor heater B1 S3 is faulty
PO 150 02 SENSOR B2 S1 CIRCUIT MALFUNCTION O2 sensor B2 S1 is faulty (Bank2)
PO 151 02 SENSOR B2 S1 CKT LOW VOLTAGE O2 sensor B2 S1 has a low signal level
PO 152 02 SENSOR B2 S1 CKT HIGH VOLTAGE O2 sensor B2 S1 has a high signal level
PO 153 02 SENSOR B2 S1 CKT SLOW RESPONSE O2 sensor B2 S1 has a slow response to enrichment/depletion
PO 154 02 SENSOR B2 S1 CIRCUIT INACTIVE O2 sensor circuit B2 S1 is passive
PO 155 02 SENSOR B2 S1 HTR CKT MALFUNCTION O2 sensor heater B2 S1 is faulty
PO 156 02 SENSOR B2 S2 CIRCUIT MALFUNCTION O2 sensor B2 S2 is faulty
PO 157 02 SENSOR B2 S2 CKT LOW VOLTAGE O2 sensor B2 S2 has a low signal level
PO 158 02 SENSOR B2 S2 CKT HIGH VOLTAGE O2 sensor B2 S2 has a high signal level
PO 159 02 SENSOR B2 S2 CKT SLOW RESPONSE O2 sensor B2 S2 has a slow response to rich/lean conditions
PO 160 02 SENSOR B2 S2 CIRCUIT INACTIVE O2 sensor circuit B2 S2 passive
PO 161 02 SENSOR B2 S2 HTR CKT MALFUNCTION O2 sensor heater B2 S2 is faulty
PO 162 02 SENSOR B2 S3 CIRCUIT MALFUNCTION O2 sensor B2 S3 is faulty
PO 163 02 SENSOR B2 S3 CKT LOW VOLTAGE O2 sensor B2 S3 has a low signal level
PO 164 02 SENSOR B2 S3 CKT HIGH VOLTAGE O2 sensor B2 S3 has a high signal level
PO 165 02 SENSOR B2 S3 CKT SLOW RESPONSE O2 sensor B2 S3 has a slow response to enrichment / depletion
PO 166 02 SENSOR B2 S3 CIRCUIT INACTIVE O2 sensor circuit B2 S3 is passive
PO 167 02 SENSOR B2 S3 HTR CKT MALFUNCTION O2 sensor heater B2 S3 is faulty
PO 170 BANK 1 FUEL TRIM MALFUNCTION Fuel leakage from fuel system block No. 1
PO 171 BANK 1 SYSTEM TOO LEAN Cylinder block No. 1 becomes lean (possibly air leaks)
PO 172 BANK 1 SYSTEM TOO RICH Cylinder block No. 1 is rich (possibly incomplete closure injectors)
PO 173 BANK 2 FUEL TRIM MALFUNCTION Fuel leakage from the fuel system of block No. 2
PO 174 BANK 2 SYSTEM TOO LEAN Cylinder block No. 2 becomes lean (possibly air leaks)
PO 175 BANK 2 SYSTEM TOO RICH Cylinder block No. 2 rich (possibly incomplete closing of the injector)
PO 176 FUEL COMPOSITION SENSOR MALFUNCTION CHx emission sensor is faulty
PO 177 FUEL COMPOSITION SENS CKT RANGE/PERF Sensor signal is out of range
PO 178 FUEL COMPOSITION LOW INPUT Low signal level of the CHx sensor
PO 179 FUEL COMPOSITION HIGH INPUT High signal level of the CHx sensor
PO 180 FUEL TEMP SENSOR A CIRCUIT MALFUNCTION Fuel temperature sensor circuit “A” is faulty
PO 181 FUEL TEMP SENSOR A CIRCUIT RANGE/PERF Sensor signal “A” is out of range
PO 182 FUEL TEMP SENSOR A LOW INPUT Low signal from fuel temperature sensor “A”
PO 183 FUEL TEMP SENSOR A HIGH INPUT High signal from fuel temperature sensor “A”
PO 185 FUEL TEMP SENSOR B CIRCUIT MALFUNCTION Fuel temperature sensor “B” circuit is faulty
PO 186 FUEL TEMP SENSOR RANGE/PERF Sensor signal “B” is out of acceptable range
PO 187 FUEL TEMP SENSOR B LOW INPUT Low signal from fuel temperature sensor “B”
PO 188 FUEL TEMP SENSOR B HIGH INPUT High signal from fuel temperature sensor “B”
PO 190 FUEL RAIL PRESSURE CIRCUIT MALFUNCTION Fuel rail pressure sensor circuit is faulty
PO 191 FUEL RAIL CIRCUIT RANGE/PERF Sensor signal is out of range
PO 192 FUEL RAIL PRESSURE LOW INPUT Low signal from the fuel pressure sensor
PO 193 FUEL RAIL PRESSURE HIGH INPUT High signal from the fuel pressure sensor
PO 194 FUEL RAIL PRESSURE CKT INTERMITTENT Fuel pressure sensor signal intermittent
PO 195 ENGINE OIL TEMP SENSOR MALFUNCTION Engine oil temperature sensor circuit is faulty
PO 196 ENGINE OIL TEMP SENSOR RANGE/PERF Sensor signal is out of range
PO 197 ENGINE OIL TEMP SENSOR LOW Low oil temperature sensor signal
PO 198 ENGINE OIL TEMP SENSOR HIGH High oil temperature sensor signal
PO 199 ENGINE OIL TEMP SENSOR INTERMITTENT Oil temperature sensor signal intermittent
PO 2XX FUEL AND AIR METERING
PO 200 INJECTOR CIRCUIT MALFUNCTION Injector control circuit is faulty
Other fault codes.
1 OEM
2 J1850 Bus+ (Bus + Line, SAE)
3 OEM
4 Body grounding
5 Signal ground
6 Upper CAN pin (J-2284)
7 K Line ISO 9141-2
8 OEM
9 OEM
10 Bus - Line, Sae J1850 Bus
11 OEM
12 OEM
13 OEM
14 CAN bottom pin (J-2284)
15 L Line ISO 9141-2
16 Battery voltage
Please note that the presence of a connector is not a 100% sign of compatibility with OBD 2. Cars equipped with this system must have a mark in the accompanying documentation. The most commonly used protocol can be identified by the presence of certain pins on the connector. OBD pinout and other connectors for various types of cars can be downloaded in the collection or see here.
The idea is not new, but there are many questions. On the one hand, you can remove almost any data, but on the other hand, OBDII is like a patchwork quilt, because... the total number of physical interfaces and protocols will scare anyone. And this is all explained by the fact that by the time the first versions of OBD specifications appeared, most automakers had already managed to develop something of their own. The appearance of the standard, although it brought some order, required the inclusion in the specification of all the interfaces and protocols that existed at that time, well, or almost all of them.
The OBDII connector according to the J1962M standard contains three standard interfaces: MS_CAN, K/L-Line, 1850, plus a battery and two grounds (signal and just ground). This is according to the standard, the remaining 7 out of 16 pins are OEM, that is, each manufacturer uses these pins as he pleases. But standardized outputs often have extended, advanced functions. For example, MS_CAN can be HS_CAN, HS_CAN can be on other pins (not specified by the standard) along with the standard MS_CAN. Pin No. 1 can be: for Ford - SW_CAN, for WAGs - IGN_ON, for KIA - check_engene. Etc. All interfaces were also not stationary in their development: the same K-Line interface was initially unidirectional, now it is bidirectional. The CAN interface’s bandwidth is also growing. In general, the vast majority of European cars of the 90s and early 2000s could be diagnosed using only K-Line, and most American cars could only be diagnosed with SAE1850. Currently, the general vector of development is the increasingly widespread use of CAN, increasing the exchange speed. We are increasingly seeing single-wire SW_CAN.
There is an opinion that an English-speaking programmer, sitting on specialized (English-language) forums, delving into the texts of the standards, can, in “maximum 4-5 months,” build a universal engine that can cope with all this diversity. In practice this is not the case. There is still a need to sniff every new car., sometimes even the same car, but in different configurations. And it turns out that they claim 800-900 types of supported cars, but in practice 10-20 are actually tested. And this is a system - in the Russian Federation the author knows of at least 3 development teams that have followed this thorny path and all with equally disastrous results: you need to sniff/customize every car model, but there are no resources/funds for this. And the reason for this is this: standard is standard, and each manufacturer, sometimes forced, and sometimes deliberately, introduces something of its own into its implementation, not described by the standard. In addition, not all data is present on the connector by default. There is data, the appearance of which needs to be initiated (to give a command to one or another unit of the car to transmit the necessary data).
And this is where OBDII bus interpreters come into the picture. This is a microcontroller with a set of interfaces that comply with the J1962M standard, translating the entire variety of data on different interfaces diagnostic connectors into a language more suitable for applications, such as diagnostic applications. In other words, the entire variety of protocols is now decrypted by the application, no matter what it is running on - on a Windows computer or on a tablet/smartphone. The first mass-produced OBDII interpreter with an open protocol was ELM327. This is an 8-bit microcontroller MicroChip PIC18F2580. Let the reader not be surprised by the fact that this microcontroller is a mass-produced device general use. The firmware is proprietary and the real cost of “PIC18F2580+FirmWare” is an impressive $19-24. That is, a scanner made on an “honest” ELM327 chip cannot cost less than 50 evergreen presidents. Why is there such a variety of scanners/adapters on the market with prices starting from 1000 rubles, you ask? And our Chinese friends did their best! How they cloned this chip, etched the crystal layer by layer or sniffed it day and night - we’ll leave it behind the scenes. But the fact remains: clones have appeared on the market (for reference: an 8-bit MicroChip controller in wholesale purchases now costs less than a dollar). Another thing is how correctly these clones work. There is an opinion that “as long as people buy cheap adapters, auto electricians will not be left without work.” That is, a person buys an adapter with the thought of “reloading or adjusting something,” but the result he gets is different, well, that is, not the one he expected. Well, for example, suddenly the multimedia system starts blinking with all its lights, or an error pops up, or even a box in emergency mode passes. And it’s good if there are no serious consequences - in most cases, a specialist with professional equipment will cure iron horse. But it also happens differently. Several factors can be mixed up here: the wrong adapter (clone), the wrong software, the wrong combination of adapter + software, and “crooked” hands can also play a role. I note that an adapter on an honest chip from a manufacturer with the right software will not lead to disastrous results, at least the author is not aware of such cases.
What can you do with such an adapter? Well, probably the most common case is to put it in the glove compartment “just in case.” Look and reset the error as soon as it appears. Reset the odometer before selling the car, or vice versa, “wind up” if you are a hired driver. Enable any option in the car that is disabled by default, but official dealer this service is paid. Updating firmware and reconfiguring electronic units will still be left to specialists, but most adapters allow this too. Some will simply like to have more information about the operating parameters of the engine and other systems in the form of beautiful graphics on a tablet or smartphone. For some reason, taxi drivers are often seen on the road with an Android tablet installed in front of them. dashboard and completely covers it, so: this tablet is most likely connected to such an adapter via Bluetooth or Wi-Fi. There are a number of other applications, such as using such an adapter in conjunction with a telematics device (tracker) or alarm system. Connecting to the diagnostic connector using such an adapter allows you to easily obtain the data necessary for monitoring. In most cases, this method costs the developer less, and the installation itself is simpler, because the need to install various sensors disappears; everything (or almost everything) can be removed from OBDII.
Another thing is that the capabilities of the chip are currently no longer sufficient for use in modern cars. Somewhere in the mid-2000s, communication speeds on the CAN bus increased, and SW_CAN appeared. But the most important thing: the length (number of characters) in code words has increased. And if in hardware it is possible, through a relay or a banal toggle switch, to stick crutches to the ELM327 that will allow you to work with MS and HS and even with SW CAN releases, then the computing power of the PIC18F2580 with its 4 MIPS is clearly not enough for long code words. By the way, latest version ELM327 (V1.4) dates from 2009. And this chip can only be used without “crutches” for cars produced before the mid-2000s. So what to do? Strangely enough, there is a way out, and more than one.
CAN-LOG, also an interpreter, but not a full set of OBDII interfaces, but two CAN buses. It turns out that this is enough to remove all necessary information. True, not all cars have both CAN buses connected to the diagnostic connector. This means you will have to connect under the instrument panel. And this is not always acceptable for reasons of maintaining the warranty, although there is an option for wirelessly retrieving information from the bus, but this is even more expensive, and the reliability of the collected data is not 100%. You can use either a ready-made device, connecting it via UART or RS232, or just a chip, integrating it onto a device board with a small number of discrete components. The cost of the device is, of course, higher than the cost of an authentic ELM327, but this is compensated by a huge list of supported cars and functions. Moreover, the list of supported cars includes not only cars, but also trucks, construction, road and agricultural equipment. CAN-LOG works slightly differently than the ELM327 and its clones. When connecting to the car tires, you must select and set the program number corresponding to the car. And this is convenient, because... the developer does not need to delve into all the variety of protocols. (In the ELM327, car selection and chip fine-tuning are left to the application).
There are other solutions that allow you to easily and elegantly remove data from the diagnostic connector. Well, the question of whether it is possible to tame the standard diagnostic connector and how, each developer will decide for himself. For a fleet of cars of the same brand, you can try to write your own software, unless of course the manufacturer closes the protocols. And if the telematics device will be installed on different models, then it makes more sense to use one of the OBDII interpreters.
