Description of the design of the engine electrical equipment (Opel Vectra C)

General information and precautions

1. The engine electrical equipment includes components of the ignition systems (petrol models), preheating (diesel models), charging and starting, as well as the electronic engine control system. Since these systems are directly related to the operation of the engine, they are considered separately from other on-board electrical equipment. The placement, design and operating principles of signal and lighting lights, control devices, etc., are described in Chapter 12.

2. The ignition system ensures the ignition of the air-fuel mixture supplied to the combustion chambers of the cylinders of gasoline engines. To form a spark of the required intensity, the 12-volt voltage of the on-board network is converted into high-voltage voltage in the ignition coils (up to 30000 V). Its main working components are spark plugs, coils and ignition module. The distribution of high-voltage supply to the spark plugs is controlled by the engine control unit (ECM) - manual adjustment of the ignition timing is not performed - if the required settings are violated, the failed components must be replaced.

3. On all 4-cylinder gasoline engines covered in this manual, (except Z20NET) 4 ignition coils (one per cylinder) are combined into a single ignition module. On 6-cylinder engines, two ignition modules with 3 coils each are installed. The coils are placed in a common housing installed above the spark plugs. The design of the module and coils eliminates the need for high-voltage wires, since the coils are connected directly to the spark plugs. The ECM, based on the analysis of the data received from the camshaft and crankshaft position sensors, in accordance with the program of the built-in processor, issues control electrical pulses to the ignition module, the configuration of which uniquely determines the ignition moment. In this case, the voltage supply to the primary windings of the ignition coils is interrupted, which leads to a sharp change in the electromagnetic field and, as a result, the generation of high-voltage voltage in the secondary winding. High-voltage voltage is supplied to the spark plugs. The interelectrode gap of the spark plugs is set in such a way that when voltage is supplied to the plug, a "breakdown" occurs between the electrodes, accompanied by sparking. The spark that results from the "breakdown" ensures the ignition of the air-fuel mixture. The ignition system controls are not subject to wear and do not require regular maintenance. In accordance with the maintenance schedule (see Chapter 1) only the spark plugs should be replaced.



4. The diesel engine preheating system is designed to warm up the combustion chambers for the purpose of confident ignition of diesel fuel. Glow plugs are used as heating elements, the operation of which is controlled by the corresponding electronic unit. A glow plug is screwed into the combustion chamber of each cylinder. The plugs are heated by electric current before starting, during starting and for some time after starting the engine. The power supply to the glow plugs is controlled by the ECM. In this case, the corresponding control lamp is displayed on the instrument panel.

5. The fuel filter of the diesel engine fuel system can also be equipped with a heating system that prevents diesel fuel from "waxing". The heating element is installed between the fuel filter and its housing. Power for heating the fuel is supplied by ECM commands through a temperature-sensitive switch built into the filter housing.

6. The charging system supplies electrical power to the ignition system, lighting and signaling devices, radio and other consumers of electrical power. It includes an alternator, a voltage regulator built into it, a charge indicator lamp, a storage battery, fuses and electrical wiring connecting these components. The alternator is driven by a belt drive from the crankshaft pulley and is installed at the front of the engine. The charging system does not require regular maintenance. However, the condition of the alternator drive belt, battery, connecting electrical wiring and its terminal connections should be checked periodically.



7. The starting system ensures that the engine is turned over in order to start it. The main components of the system are the starter with the traction relay installed on it, the battery, the ignition switch and the connecting electrical wiring. The starter assembly with the traction relay is fixed to the power unit, near the clutch dome. When the ignition key is turned to position "III" (START), the power supply from the battery is supplied to the starter traction relay via the starting control circuit. The relay switches the battery power supply directly to the starter electric motor. The motor begins to rotate, simultaneously turning the engine crankshaft by the toothed ring gear of the flywheel/drive disk.

8. Engine management system (see also Chapter 4) is the main connecting element of all the above systems - it is the brain of the engine. The initial data comes to the electronic module of the system from various information sensors and other electronic components (switches, relays, etc.). Based on the analysis of data received from information sensors and in accordance with the basic parameters stored in the processor memory, the ECM generates commands to operate various control relays and actuators, thereby adjusting the engine operating parameters and ensuring maximum efficiency with minimum fuel consumption.

9. The ECM is a complex set of electronic circuits and independent attempts to make any changes will lead to disruption of its functioning and engine failures. A complete diagnosis of the engine management system can only be performed using special diagnostic equipment that allows reading the failure codes stored in the processor memory. Analysis of the read information allows you to quickly identify the source of the failure and eliminate the cause of its occurrence.

Precautionary measures

Warning: The electronic ignition system generates very high voltage! Persons with an implanted pacemaker must not be allowed to service ignition system components!

10. When servicing components of electrical equipment systems, special precautions must be taken to avoid the risk of failure of semiconductor elements, as well as to prevent electrical injuries.

11. When servicing electrical equipment, be sure to remove watches, rings, and other metal jewelry. Even with the battery disconnected, the discharge of capacitors when their terminals are accidentally grounded can result in an electric shock or severe burn.

12. Do not reverse the polarity when connecting the battery. Components such as the generator or electronic control units contain semiconductor elements that can be damaged if the wires are connected incorrectly.

13. When starting the engine from an external power source or connecting a charger, also observe the polarity of the wire connections.

14. Never start the engine with the charger connected to the battery. Always disconnect both cables from the battery before charging it from an external power source (negative at first).

15. Remember that excessively long cranking of the engine with the starter can cause serious damage to the electric motor of the latter due to overheating. Try not to use the starter continuously for more than 20 seconds on petrol models and 30 seconds on diesel models, after which it should be allowed to cool for a minute.

16. When performing electrical checks and before connecting/disconnecting diagnostic equipment, turn off the ignition. Never disconnect electrical wiring from the battery, generator or diagnostic equipment while the engine is running.



17. Never check the presence of generator output voltage by grounding its terminals. Also, do not ground the ignition coil windings to ground.

18. When performing any maintenance work on electrical equipment, ensure that the negative cable is disconnected from the battery.

19. Before using arc welding, always disconnect the battery, generator and components such as the fuel/ignition system ECM to avoid the risk of damage.

20. Avoid allowing hands, hair and loose clothing to come into contact with the rotating alternator drive belt during checks performed with the engine running.

21. Before steam cleaning the engine compartment, wrap the generator in a plastic bag, which should then be securely fastened with rubber bands.

Ignition Timing Angle - General Information

1. The ignition timing angle is programmed in the electronic engine control module and is adjusted automatically when the engine is running.

2. Before programming, it is necessary to check the coincidence of all marks when setting the TDC of the corresponding piston (as a rule the first) engine cylinder in the compression stroke.