The post-heating mode is designed to improve the starting characteristics of the engine, even out the operation of the engine during a cold start, and prevent the appearance of blue smoke (incompletely burned fuel) after starting the engine.
The duration of the glow plug heating phases depends on the coolant temperature.
VN 9.006
Dependence of the preheating time on the coolant temperature t. Heating time, s T. Coolant temperature in degrees Celsius