The ZMZ-406 engine is equipped with a microprocessor-based ignition system, which consists of a control unit for fuel injection and ignition systems, two ignition coils of types 30.3705 or 301.3705, spark plugs, high-voltage and low-voltage wires
The control unit is installed in the passenger compartment on the right side under the instrument panel, behind the upholstery of the sidewall of the body.
The ignition coils are mounted on the cylinder head cover.
The control unit receives signals from sensors installed on the engine and, based on this, corrects the ignition timing, which allows obtaining optimal power, economic and toxicity indicators.
Electric diagram of the integrated microprocessor engine control system (KMSUD)
Disconnect the wire from the "negative" terminal of the battery.
Disconnect 4 blocks 1 of low-voltage wires and high-voltage wires 5 from the coil.
Remove bolts 2, remove bar 3 and coil 4.
Remove the second coil in the same way.
Coils 30.3705 and 301.3705 are checked by a spark plug diagnostician 1AP975000 on a car.
To do this, disconnect the high-voltage wires from the coil and connect the diagnostic tool instead
Then crank the engine with a starter, while a spark should jump in the diagnostic spark gap in time with the operation of the cylinders.
Check the primary resistance of the ignition coil by connecting an ohmmeter between the low voltage terminals.
The ohmmeter should show a resistance of 0.025-0.03 ohm.
Then check the resistance of the secondary winding by connecting an ohmmeter between the high voltage terminals of the ignition coil.
The ohmmeter should show a resistance of 4000-5000 ohms.
If the measured parameters differ from those indicated, the coil must be replaced.
Install the ignition coil in the reverse order of removal.