FixVault

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

ENGINE 113.990 in MODEL 211, 219 

ENGINE 113.991 in MODEL 215, 220 

ENGINE 113.992 in MODEL 230 up to Model Year 2008 

ENGINE 113.993 in MODEL 463 up to 31.5.12 

ENGINE 113.995 in MODEL 230 up to Model Year 2008 

Fig 1: Identifying Overheating/Pinging Protection Function Diagram
G07870983Courtesy of MERCEDES-BENZ USA

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

If the coolant temperature/charge 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.

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

The ignition timing is retarded e.g.:

-at  100°C coolant, 20°C charge air and full load 2° crank angle

-at  100°C coolant, 60°C charge air and full load 8° crank angle

-at  125°C coolant, 60°C charge air and full load 11° crank angle

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

IMPORTANT The ignition angle corrections of the overheating/pinging protection and anti-knock control are added based on the performance map.

  Crankshaft position sensor, location/task/design/function   GF07.04-P-4116AM
  Camshaft Hall sensor, location/task/design/function   GF07.04-P-4117HA
  Pressure sensor, location/task/design/function   GF07.04-P-5014AM
  Coolant temperature sensor, location/task/design/function   GF07.04-P-5026AM
  Charge air temperature sensor, location/task/design/function   GF07.04-P-5039AM
  ME-SFI control unit, location/task/design/function   GF07.61-P-5000AM 
  Spark plugs, location/task/design/function   GF15.10-P-3101AM
  Ignition coils, location/task/design/function   GF15.10-P-3102AM
  Throttle valve actuator, location/task/design/function   GF30.22-P-4101AM