LEXUS RX 300

1998 - 2003 of launch

Repair and operation of the car

Diagnostic of systems of electronic control and diagnostic equipment

General information

System of autodiagnostic one of side (OBD)

Several diagnostic creation of devices that it controls of separate parameters of systems of the car and fixes the refusals revealed in the memory of the processor of side in the form of individual codes of bad functioning is a part of the system OBD.

The models described in the present manual equip of the system of the diagnostic one of side of the second generation (OBD II) which basic element is the processor of side more very often called by one unity of electronic control (ECM).

ECM is a brain of a system of control of the motor. The basic data reach the module of several sensors of information and electronic component others (switches, the alternation, etc.). On basis of the analysis of these data, and according to the basic parameters they install in the processor memory, ECM develops orders of the operation of several operational alternations and mechanisms of actuation, executing through that the agreement of parameters of work of the motor and supplying the very efficiency of his return in the moment of the consumption of least fuel.

The communication between ECM and n ° one organizes 3 DLC in OIS 9141-2. The contacts in n ° 3 DLC is located according to the SAE J1962 and OIS 9141-2 standards.

Contacts of the capture DLC n ° 3

4 - Connection with the case 5 - the Case - an alarming conclusion 7 - the Line K of diagnostic data (OIS 9141-2) 15 - the Line L of diagnostic data (OIS 9141-2) 16 - Battery tension for a security lock (in any position of the lock of ignition)

Given on diagnostic unities

The control of the usefulness of the functioning of component ones of systems of injection and reduction in the toxicity of OG happens through the instrument of measuring universal foxglove (multímetro). The use of the instrument of measuring foxglove is preferable for several reasons. First of all, in analogous devices it is quite difficult (sometimes - it is impossible), in order that it defines the result of the indication inside the 100th actions and thousand of actions while during the inspection of the outlines including component electronic in the structure, such exactness is particularly important. The second, not less important, the fact that the internal outline of a digital multímetro, has the quite high impedância is the reason. Since the voltômetro joins the chain checked in the parallel one, the exactness of the measurement of subjects is higher, of what the least current will pass in fact by the device. This factor is not essential in the moment of the measurement of quite high values of the tension (9÷12 of V), nevertheless make the definition into the diagnostic one of the elements that give signs of low tension, such as, for example, it tries of lambda where it is on the measurement of actions of the volt.

The parallel observation of parameters of signs, resistance and tension in all the chains of the management is possible through the fendedor included constantly in the capture of the unity of control of the motor. At the same time in the motor off, of work or during the movement of the car, the measurement of parameters of signs in captures of fendedor is executed of what the conclusion on possible defects is taken away.

The special diagnostic scanners or the provers with certain cartridge (if it is supplied), a universal thread and the capture can accustom to the diagnostic one of electronic systems of the motor, in, the ABS, men's systems and other. Besides, there is possible there uses the specialized motorcar expensive diagnostic computer that is developed specially for the diagnostic flood of most of systems of modern cars to this objective (for example, ADC2000 of the Launch HiTech). Also, it is possible to use scanners and specialized diagnostic analyzers to this objective, for example, FDS 2000, Bosch (www.bosch.de) FSA 560, KTS500 (0 684 400 500) or the ordinary personal computer with the special adaptador, a thread (for example, a play 1 687 001 439) and the browser of program OBD II installed one.

Some scanners, besides usual operations of the diagnostic one, allow to print, in the connection with the personal computer, the schematic diagrams of electric equipments that are guarded in the memory of the unity of control (if you arrange if they put), to plan the system that is antidragged, to observe signs in chains of the cars in real time.