Contents: Examination ⇓ Replacement ⇓
Examination
1. The ignition control unit is an electronic switch that breaks the ground circuit of the primary winding of the coil at the right moment, causing a high voltage pulse in the secondary winding, which is necessary to generate a spark in the spark plug.
2. There is no special test separately for the control unit. The block is checked by exclusion. If the voltage supply and grounding circuits are in good condition, then the control unit may be faulty. On some models, the ignition control unit is structurally combined with the distributors; the entire unit will have to be replaced. But before you go out and buy an expensive device that you may not need, have the control unit checked by a qualified auto electrician.
3. Check if battery voltage is supplied to the control unit. To do this, disconnect the block connector and measure the voltage at the input contact of the connector (see the electrical diagrams at the end chapter 12).
4. If there is no voltage supplied to the control unit, check the connection from the control unit to the ignition switch. First, check the integrity of the fuses in the box under the hood. Trace the circuit to the ignition switch and make sure that when the ignition is on, there is voltage at its contact connected to the control unit. Find the fault using the electrical diagram.
5. If the ignition coil circuits and the coil itself are in good condition, but there is no spark, the control unit may be faulty. Have the control unit checked by a qualified electrician.
Replacement
6. This information only applies to models with a separate ignition control unit. If the control unit is combined with the distributor, the distributor must be replaced (see paragraph 9).
7. Disconnect the negative cable from the battery.
Warning. If your vehicle's audio system is equipped with anti-theft protection, make sure you know the unlock code before disconnecting the battery.
8. Disconnect all electrical connectors from the control unit (the unit is located next to the battery or on the left upper support of the front suspension in the engine compartment).
9. Loosen the nuts or bolts securing the unit and remove it from the vehicle.
10. Installation is carried out in reverse order.