GF07.61-P-4027MIS Overheating/Pinging Protection, Function

GF07.61-P-4027MIS Overheating/Pinging Protection, Function
- as of model year 09


Function requirements for overheating/knock protection, general points
^ Circuit 87M ON (engine control ON)
^ Engine running

Overheating/knock protection, general points
In case of thermal overload, the overheating/knock protection protects against engine damage and overheating damage to the firewall catalytic converter.

The ME-SFI [ME] control unit (N3/10) controls the overheating/knock protection according to information from the following sensors:
- Hot film MAF sensor (B2/5), engine load
- Intake air temperature sensor (B2/5b1)
- Coolant temperature sensor (B11/4)
- Crankshaft Hall sensor (B70), engine speed

Overheating/knock protection function sequence
If the coolant or intake air temperature is too high, the ME-SFI [ME] control unit no longer fully opens the throttle valve actuator (M16/6), depending on engine speed and load. The ME-SFI [ME] control unit shortens the injection time at the fuel injection valves (Y62) according to the lower air mass.

The ME-SFI [ME] control unit also actuates the heating element in the three-disk thermostat valve (Y110), so that the three-disk thermostat is fully open and all the coolant is cooled by the engine radiator.