Never disconnect the battery while the engine is running.
When charging the battery with a fast charger, disconnect the battery from the vehicle electrical system. Do not use a fast charger to start the engine.
Before checking the injection system, make sure that the ignition system is working properly, that is, the ignition and spark plugs correspond to the specified parameters.
At temperatures above +80°C (drying after painting) remove the electronic control unit.
Do not disconnect or connect the electronic control unit connector when the ignition is on.
When checking compression, disconnect the power supply to the fuel pump relay, for which remove the main injection system relay "2". The relay is located in the relay box on the left in the engine compartment.
The system is under pressure. Therefore, before replacing parts, relieve the pressure in the system. To do this, carefully disconnect the fuel supply line and place a rag around the pipeline.
If the engine has been standing for several hours, the pressure will release by itself during this time.