FixVault

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

ENGINE 275.953 in MODEL 216, 221 up to Model Year 8 

ENGINE 275.982 in MODEL 216, 221 up to Model Year 8 

Fig 1: Overheating/Pinging Protection Function Diagram
G07510398Courtesy of MERCEDES-BENZ USA

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.

At high engine load and coolant temperature, the ignition timing point is retarded corresponding to the rotational speed and load and the throttle valve is no longer opened completely.

The ignition timing point adjustment begins at approx. 90°C coolant temperature. The timing correction towards "late" is performed by the ME-SFI control unit (N3/10) in accordance with the performance map

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

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

ME-SFI control unit, location/task/design/function GF07.61-P-5000M 
Coolant temperature sensor, location/task/design/function GF07.04-P-5026M 
Crankshaft position sensor, location/task/design/function GF07.04-P-4116M 
Pressure sensor upstream of throttle valve actuator, location/task/function GF07.04-P-5048M 
Pressure sensor downstream of throttle valve actuator, location/task/function GF07.04-P-5049M 
Charge air temperature sensor, location/task/function GF07.04-P-5038M 
Throttle valve actuator, location/task/design/function GF30.22-P-4101M
ECI ignition system, function GF15.15-P-3000M
Boost pressure control, function GF09.40-P-3000M