(If your car is equipped with OBD II, there should be an entry on the nameplate under the hood "OBD II compliant" and must have a 16-pin connector. As a rule, OBD II equipped models starting from 1996 release).
1. The OBD system includes several diagnostic devices that monitor individual parameters of the toxicity reduction systems and fix the detected failures in the on-board processor memory in the form of individual fault codes. The system also checks sensors and actuators, controls vehicle maintenance cycles, provides the ability to store even short-term failures during operation and clear the memory block.
Location of the diagnostic connector
2. All models described in this manual are equipped with a second generation on-board diagnostic system (OBD–II). The main element of the system is the onboard processor, often called the electronic control module (ECM), or a power unit operation control module (RSM). The PCM is the brain of the engine management system. The initial data is fed to the module from various information sensors and other electronic components (switches, relays, etc.). Based on the analysis of the data coming from the information sensors, and in accordance with the basic parameters stored in the processor's memory, the PCM generates commands for the operation of various control relays and actuators, thereby adjusting the operating parameters of the engine, and ensuring maximum efficiency of its output with minimal fuel consumption. The OBD-II processor memory data is read using a special scanner connected to the 16-pin diagnostic connector for reading the database (DLC), located under the heater control panel.
Attention: On some models, the fault codes stored in the memory of the self-diagnosis system can be read using a lamp "Check engine".
3. Engine management/emission control system components are subject to a special extended warranty. You should not attempt to independently diagnose PCM failures or replace system components before the expiration of these obligations - contact the specialists of representative service stations. Information about diagnostic tools The use of a high-impedance digital multimeter in the diagnostics of the systems under consideration significantly increases the accuracy of measurements.
4. Checking the correct functioning of the components of the injection systems and reducing the toxicity of exhaust gases is carried out using a universal digital meter (multimeter). The use of a digital meter is preferred for several reasons. Firstly, it is quite difficult for analog devices to (sometimes impossible), to determine the result of the indication with an accuracy of hundredths and thousandths, while when examining circuits that include electronic components, such accuracy is of particular importance. The second, no less important, reason is the fact that the internal circuit of a digital multimeter has a fairly high impedance (the internal resistance of the device is 10 mΩ). Since the voltmeter is connected in parallel to the circuit under test, the measurement accuracy is higher, the smaller the current will pass through the device itself. This factor is not significant when measuring relatively high voltage values (9-12V), however, it becomes decisive in the diagnosis of elements that produce low-voltage signals, such as, for example, a λ-probe, where it is a question of measuring fractions of a volt.
Parallel monitoring of signal parameters, resistances and voltages in all control circuits is possible using a splitter connected in series to the engine control unit connector. At the same time, with the engine turned off, running or while the car is moving, the parameters of the signals at the splitter terminals are measured, from which a conclusion is made about possible defects.
5. Special diagnostic scanners are used to diagnose electronic systems of the engine, automatic transmission, ABS, SRS (Pointer) or testers (Retriever) with a specific cartridge (if provided), universal cable and connector. In addition, for this purpose, you can use an expensive specialized automotive diagnostic computer, specially designed for the complete diagnosis of most systems of modern cars (e.g. ADC2000 from Launch HiTech, or ESA560, FSA, BEA from Bosch), or a regular computer with a special cable and an OBD browser program (e.g. Bosch ESI[tronic] program in Russian (www.ESItronic.com, Motor-tester, Mytester, VagCom and VagTool programs or available from www.carsoftinternational.com or www.obd-2.com).
Universal adapter K-L-line, used to match the signals of the RS-232 port and ISO-9141 interfaces (K–line) and ALDL. Various cables can be connected to the adapter connectors, which are necessary for diagnosing a particular brand of car. The switches and display elements installed in the adapter allow you to select the required operating modes and roughly evaluate the operation of the output lines. So, the glow of the green LED marked L-line indicates the connection of the L line with the car body. The glow of the red LED marked K-line indicates a high potential that is present at that moment on the K line. When the connection with the car is established, the blinking of the indicators may not be noticeable to the eye due to the high exchange rate. Connection to a computer is made directly to the 25-pin COM port or using "RS-232 cables 25 pins – 9 cont." to the 9-pin COM port.
Some scanners, in addition to the usual diagnostic operations, allow, when connected to a personal computer, to print circuit diagrams of electrical equipment stored in the memory of the control unit (if laid down), program the anti-theft system, observe the signals in the car circuits in real time.
You can download a free version of the OBD II browser for diagnosing your car from arus.spb.ru.
6. Reading the fault codes recorded in the memory of the self-diagnosis system, on some vehicles, can also be done using the indicator "check engine" on the dashboard.
7. For diagnostics, for example, devices from ToolRama, Inc. can also be used. (3500 NW Boca Raton Blvd., Boca Raton, Florida, 33431, USA 1 877 866 5726 – 561 750 4511 – 561 338 8447 FAX):
- R000 tester or P000 scanner with T043 or T053 cartridge,
- universal cable N000,
- black or white connector N003;
- multiplexer N002A;
- connector N004.
8. The scanner only reads the entered fault memory and clears the fault memory. In addition, the scanner only supports the ISO protocol. The tester can additionally activate and display current data and supports SAE and ISO protocols.
All tester cartridges can also be used in the scanner. In this case, the functions will be limited to only reading and clearing memory.
9. For most vehicles manufactured since 1996 that support the SAE/ISO 9141 OBD II protocol, an OBD II cartridge can be used that performs the following functions:
Reading and clearing OBD II trouble codes. Displays oxygen sensor test results.
Continuous monitoring of ignition, injection and component systems.
Displaying a list of current data and fixed transient failures:
- Absolute pressure in the inlet pipeline;
- Oxygen sensor voltage;
- Engine coolant temperature;
- Estimated engine load;
- vehicle speed;
- fuel quality;
- Air flow (by weight);
- Ignition advance;
- Throttle position;
- Intake air temperature.
In addition to trouble codes "P0 ", the instrument also displays extended codes "P1 " for models Acura, Audi, BMW, Chrysler, Dodge, FORD, Geo, GM, Honda, Hyundai, Infinity, Kia, Lexus, Lincoln, Mercury, Mazda, Mercedes, Mitsubishi, Nissan, Porsche, Saturn, Seat, Skoda, Subaru, Suzuki, Toyota, Volvo, VW. 10. ADC2000 dedicated automotive diagnostic tool features:
- Built-in 4-channel oscilloscope with standard preset for 19 probes.
- Ignition analyzer for testing primary and secondary circuits (with voltage up to 100 kV) on systems with a distributor or separate ignition coils - with control of burning time, peak voltage, ignition timing, current, and revolutions.
- Two-channel multimeter with digital and graphical representation of voltage data (150 V), frequency (1100 kHz), current (150 A).
- Built-in scanner for the main systems on cars: VAG, MB, BMW, Volvo, Toyota / Lexus, Mitsubishi, Nissan, Honda, Mazda, GM, Ford, Chrysler, Daewoo, Hyundai, Kia, Samsung, as well as on cars that support the OBD protocol - II.
- Cartridges are not required - you can update the device programs yourself by downloading the necessary updates from the Internet.
- Software for communication with a personal computer.
11. Information on the use of these devices is contained in the enclosed documents. You can get acquainted with details about devices on the sites programatools.com, bosch.de.
12. For diagnostics, we recommend that you seek qualified help from service station specialists.
ISO 9141–2 (Chrysler, European and most Asian models) Pins 4, 5, 7, 15, 16
Output No | Purpose
|
4 | Compound with body |
5 | Frame - signal output |
7 | Line K, ISO 9141 |
15 | Line L, ISO 9141 |
16 | Plus batteries through the fuse. Under voltage, in any position of the ignition switch |
Reading fault codes
The information content of the bits of the code Type P 0 3 8 0 from left to right:
1 rank (left)
P | power unit |
B | body |
WITH | chassis |
2nd digit Code source
0 | standard SAE |
1 | advanced - manufacturer-specified |
3 digit System
0 | system as a whole |
1 | air mixing (air/fuel induction) |
2 | fuel injection |
3 | system ignition or misfiring |
4 | additional release control (auxillary emission control) |
5 | speed car and control x.x. |
6 | input and output signals of the control unit |
7 | transmission |
4.5 digits
Sequence number of component or circuit failure (00–99)
Order of execution
1. If a malfunction is detected that repeats in a row in two trips, the PCM issues a command to turn on the warning lamp built into the instrument panel "Check engine", also called the failure indicator. The lamp will continue to burn until the memory of the self-diagnosis system is cleared of the fault codes entered in it (refer to Specifications). If the lamp flashes, a malfunction has been registered that can damage the catalytic converter. Reduce speed until the lamp goes out or stays on. Reading fault codes in the OBD-II system can be done in various ways. The main way is to read using the devices described above, connected to the 16-pin DLC connector of the OBD-II system. Other methods are not available on all models. On some models flashing code (manufacturer-specific and different from SAE codes) can be read with a digital voltmeter or LED. It is possible to read the code on the lamp "Check engine".
2. Without starting the engine, turn on the ignition, - control lamp "Check engine" should light up, otherwise it should be replaced. After checking the serviceability of the lamp, turn off the ignition again.
If the system memory is clear, the indicator lamp will not turn on.
Starting the engine automatically terminates access to the diagnostic system.
Clearing the OBD-II memory
3. When a fault code is entered into the PCM memory, a warning lamp lights up on the vehicle's instrument panel "Check engine". The code remains stored in the module's memory.
4. To clear the ECM memory, connect a scanner to the system and select the CLEARING COEDS function from its menu (Deleting codes). Then follow the instructions displayed on the device, or immediately remove the EFI fuse from its socket in the mounting block for 30 seconds. Alternatively, system memory can be cleared by removing the fuse link (the main fuse of the onboard power supply system), (you can also just disconnect the positive wire from the battery).
It is not advisable to clear the OBD memory by disconnecting the negative cable from the battery, as this will erase the engine settings and disturb the stability of its speed for a short time after the initial start.
If the stereo system installed in the car is equipped with a security code, before disconnecting the battery, make sure that you have the correct combination to activate the audio system!
Disconnecting the battery also deletes the receiver's favorite radio stations. To avoid damage to the ECM, disconnect and connect it only with the ignition off!
5. Make sure the system memory is cleared before installing new emission control system components on the engine. If the fault memory is not cleared before starting the system after replacing a failed information sensor, the PCM will enter a new fault code into it. Clearing memory allows the processor to reconfigure to new parameters. In this case, in the first 50-20 minutes after the initial start of the engine, some violation of the stability of its revolutions may occur.
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