GF07.61-P-4016CY ME Engine Coolant Heat Management Function

GF07.61-P-4016CY ME Engine Coolant Heat Management Function
- up to model year 08

Component Identification:

Heat management controls the coolant temperature of the engine. Advantages from this are:
^ Operating temperature is reached faster
^ Reduction of the exhaust gas emissions
^ Fuel savings (up to around 4%)
^ Improved heat comfort.

Heat management is dependent on the following input signals:
^ Coolant temperature
^ Engine load
^ Engine speed
^ Outside air temperature
^ Intake air temperature
^ Fan operation
^ Vehicle speed
^ Driver type (quiet or sporty)

Depending on the operating conditions (as a function of a characteristic map (N3/10) the ME-SFI [ME] control unit [ME] actuates the heating element in the coolant thermostat (Y110) with a ground signal. The voltage is supplied through "terminal 87 M".
Through heating the three-disk thermostat in the coolant thermostat opens. In this way the coolant temperature of 80 to 100 °C is regulated via the duty cycle.

If the coolant temperature is too high, the coolant temperature warning lamp (A1e54) in the instrument cluster (A1) is actuated. For this purpose the ME-SFI [ME] control unit transmits a corresponding signal to the instrument cluster via the chassis CAN (CAN E).

Full throttle position (A)
For a cold start the three-disk thermostat is not heated. In addition the heating circuit is closed via the heating system shutoff valve (Y16/2) when the vehicle heating is switched off.
The standing coolant in the engine now warms up very quickly. The engine oil is warmed up over the heat exchanger at the front on the engine.

The closing plate on the three-disk thermostat opens but dependent on the pressure (by the rotating coolant pump) from about 3500 rpm (short circuit operation).

Short-circuit operation position (B)
From an outside temperature >12 °C and a coolant temperature of 45 °C or from a coolant temperature of about 70 °C, switching to short-circuit operation takes place.
For short-circuit operation the three-disk thermostat is heated less and part of the coolant flows back into the engine circuit. Short- circuit operation is throttable, so that the heating triggers more quickly.

Mixed fuel operation position (C)
The mixed-fuel operation is enabled if the coolant temperature reaches 98 °C for the first time after the start.
For mixed-fuel operation the three-disk thermostat is heated in such a way that the coolant flows through the engine radiator and the engine circuit.

At partial load, the three-disk thermostat regulates at an increased coolant temperature of around 100 °C.
In order to prevent critical coolant temperatures from occurring, the range of increased coolant temperature is lowered under the following conditions:
^ Outside temperature < 12 °C to a coolant temperature of about 90 °C
^ Outside temperature < 12 °C to a coolant temperature of about 80 °C
^ Intake air temperature >38 °C
^ Engine speed >3000 rpm
^ Engine load > 30 %
^ Sporty driver

Radiator operation position (D)
The three-disk thermostat is heated constantly during radiator operation. The coolant only flows through the engine radiator.

For a coolant temperature above around 110 °C, the three-disk thermostat is always fully opened independently of heating (emergency operation function).