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Compensation

Compensation


Temperature compensation

At a specific engine load (mg air/combustion), a specific quantity of air is drawn into the cylinder during the induction stroke. If the temperature of the coolant or intake air is low, the air will have a higher density than normal. This means that the pressure in the combustion chamber when combustion begins will be lower. At lower gas pressure, the speed of combustion is lower, which means that the ignition must be further advanced.

The control module's memory contains two tables specifying the number of degrees by which the ignition must be advanced, depending on the coolant temperature or intake air temperature.