Attention! Do not touch the computer terminals with your hands: the engine control system is microprocessor-based and its electronic components can be damaged by electrostatic discharge.
Getting Started with Car Repair (especially if the operations are related to the dismantling of elements of the engine control system), disconnect the terminal from the negative battery terminal.
Warning! When the battery is disconnected from the vehicle's network, fault codes will be deleted from the computer's memory. Therefore, before checking the engine management system using diagnostic equipment (for example, DST-2M) do not remove the terminals from the battery terminals.
In many cases, to check the elements of the engine control system, it is necessary to have a supply voltage in the electrical circuit of the system. At the same time, it is allowed to disconnect the wire blocks from the sensors and actuating elements of the engine control system only after the ignition is turned off.
Attention! Disconnect the wiring harness block from the computer only after removing the terminal from the negative battery terminal.
If it is necessary to connect the battery to the car's electrical network during repairs, first make sure that the disconnected wires (terminal blocks, wire ends) not closed to "mass", and the ignition is off. Connect the battery positive terminal first and then the negative terminal. Switch on the ignition only for the duration of the measurements.
Attention! The engine management system uses electronic components, the supply voltage of which is 5 V. Supplying voltage to them from the vehicle's electrical network (voltage in which more than 12 V) will damage the engine control system.
To check the engine management system, use a multimeter; the internal resistance of the device in voltmeter mode must be at least 10 MΩ. If necessary, a test lamp can be used to test 12 V power circuits, but the lamp power must be less than 4 watts. A control lamp for the instrument panel A 12-1.2-1 with a power of 1.2 W or a cigarette lighter lamp AMN 12-3-1 is suitable (3 W).
Before starting the engine, make sure that the terminals are securely fastened to the battery terminals.
Attention! To avoid failure of the electronic components of the ECU, do not disconnect the wire terminals from the battery terminals while the engine is running.