Ignition system — general information (Chevrolet Trailblazer 1)

All models described use a distributorless ignition system, which consists of a battery. six coils (one for each cylinder), spark plug boots, spark plugs, camshaft position sensor, crankshaft position sensor and control system module (PCM).

On all models, the ignition phases and operating parameters of the spark plugs are controlled in the control unit. The ignition timing angle cannot be adjusted.

The crankshaft position sensor sends a signal that determines the engine speed and the position of the crankshaft. Based on the pulses received, the control unit monitors the phases and operating parameters of the ignition.

The camshaft position sensor works similarly to the crankshaft sensor, but for every revolution of the camshaft, its sensor generates one pulse. The signals from this sensor do not have a significant impact on engine operation - the pulses serve as the basis for determining misfires in the PCM, as well as for synchronizing the phases of the fuel equipment.

To detect detonation, the system is equipped with a special sensor, which also registers the presence of pre-ignition (usually caused by the wrong brand of fuel). When the sensor interacts with the PCM unit, the ignition phases are adjusted. When detonation is detected in the control unit, the phases are adjusted until it disappears. The presence of knock sensors allows you to maximize the potential of spark plugs on the verge of detonation (but without its occurrence). This ensures maximum engine performance and fuel economy.