Examination
1. Prepare the car for work (see "Preparing the car for maintenance and repair").
2. Remove the decorative engine cover (see "Engine trim - removal and installation").
3. Press the locking device of the wiring harness block.
While holding the retainer in this position, disconnect the wiring block from the ignition coil of the first cylinder.
4. Turn on the ignition and measure the voltage at terminal 3 of the wiring harness connector with a voltmeter (the terminal numbers are marked on the ignition coil).
5. Similarly, we check the supply voltage to the ignition coils of the second, third and fourth cylinders.
Note: The voltage at the terminal must be at least 12 V. If the voltage does not reach the connector or is less than 12 V, the battery is discharged, there is a fault in the power supply circuit, or the ECU is faulty.
Warning! After completing the voltage measurement, turn off the ignition.
6. Using an ohmmeter, measure the resistance between the coil terminals. The electrical resistance between terminals 1-3 should be close to zero (about 1 Ohm). The resistance between terminals 1-2 and 2-3 should be large (strive for infinity).
The faulty coil must be replaced.
Removal
7. With a socket wrench by 10 mm unscrew the bolt securing the ignition coil to the cylinder head cover.
8. Remove the ignition coil from the spark plug well.
Installation
We install the ignition coil in the reverse order.
(The article is taken from the website: VAZbook.ru)