Overheating/pinging protection, function - GF07.61-P-4027SM

ENGINE 113.986 

ENGINE 113.987 

ENGINE 113.988 

ENGINE 113.989 

Fig 1: Overheating / Pinging Protection, Function (Engine 113)

The task of the overheating/pinging protection is to prevent engine damage as a result of excessive thermal overload and overheating damage of the catalytic converters.

If the coolant temperature/intake air temperature is too high, the ignition timing point is retarded in line with engine speed and load. The correction by retarding the ignition timing is map-controlled by the ME control unit (N3/10)

The retardation of the ignition timing point commences at a coolant temperature of approx. 90 °C and an intake air temperature of approx. 20 °C.

The ignition angle timing is retarded e.g.:

• at  100 °C coolant, 20 °C intake air and full load 2° crank angle
• at  100 °C coolant, 60 °C intake air and full load 8° crank angle
• at  125 °C coolant, 60 °C intake air and full load 11° crank angle

The following information is processed in the ME-SFI control unit for this purpose:

• Coolant temperature
• Intake air temperature
• Intake manifold air pressure
• Engine speed
• Camshaft/crankshaft position (ignition circuit detection)
• Throttle valve position

The ignition angle corrections of the overheating or knocking protection and the anti-knock control are added depending on the performance map.