On-board self-diagnosis system (OBD)
The models described in this manual are equipped with a second generation on-board diagnostic system (OBD II).
The OBD II system data is read using a special scanner, for example, Consult-II, connected to a 16-pin diagnostic connector (DLC) by means of a special cable with an adapter. With the help of the same scanner, the processor memory is also cleared. It would be wise to leave the procedures for reading DTCs and clearing the ECM memory to a workshop.
Information about diagnostic tools
Checking the correct functioning of the components of the injection systems and the reduction of exhaust gas toxicity 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 it's impossible), 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 the digital multimeter has a fairly high impedance. 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÷12 V), however, it becomes decisive in the diagnosis of elements that produce low-voltage signals, such as, for example, a lambda probe, where we are talking about measuring fractions of a volt.
Parallel monitoring of signal parameters, resistances and voltages in all control circuits is possible using splitter, connected in series to the connector of the engine control unit. At the same time, with the engine turned off or running, or while the car is moving, the signal parameters are measured at the splitter terminals, from which a conclusion is made about possible defects.
To diagnose the electronic systems of a car, special diagnostic scanners or testers with a specific cartridge can be used (if provided), universal cable and connector. In addition, for this purpose, you can use a specialized automotive diagnostic computer, specially designed for the complete diagnosis of most systems of modern cars (For example, ADC2000 from Launch HiTech). Also, for this purpose, you can use scanners and specialized diagnostic analyzers, for example, FDS 2000, Bosch FSA 560, KTS500 (0 684 400 500) or a regular personal computer with a special adapter, cable (For example, set 1 687 001 439) and installed program browser OBD II.
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 any), program the anti-theft system, observe the signals in the car circuits in real time.