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

ENGINE 156.980 in MODEL 164, 251 up to Model Year 8 

ENGINE 156.982 in MODEL 209 

ENGINE 156.983 in MODEL 211, 219 

ENGINE 156.984 in MODEL 216, 221 up to Model Year 8 

Fig 1: Identifying Overheating/Pinging Protection CAN Function Diagram

Courtesy of MERCEDES-BENZ USA

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

The heat output by the cooling system into the environment is mainly dependent on the fan speed, vehicle speed, outside temperature and coolant temperature.

To avoid exceeding the maximum permissible coolant temperature, the heat generated by combustion and supplied to the cooling system and thus the engine output must be restricted.

To do this the throttle valves are no longer opened fully. The air mass drops accordingly and less fuel is injected.