General
For vehicles with a combustion engine, the circulation pump delivers the coolant through the heater core and the combustion engine. On vehicles with an electric motor, the circulation pump delivers the coolant through the condenser, the high-voltage PTC heater and the heater core. The control for the climate control actuates the circulation pump directly.
The following functions can request actuation of the circulation pump (depending on model and equipment installed):
Climate control
The circulation pump is used to support the coolant pump when the engine is running. When the residual heat system mode or the heater booster function is switched on, it pumps the coolant through the combustion engine and the heater core.
Stationary heater
When the stationary heater is switched on, the circulation pump feeds the heated coolant through the combustion engine, heater unit and the heater core.
Pre-air conditioning
When the pre-entry climate control is activated, the circulation pump delivers the coolant through the high-voltage PTC heater and the heater core.
ECO start/stop function
At "Engine stop" the circulation pump feeds the coolant through the combustion engine and the heater core.
Turbocharger afterrun cooling
In diesel vehicles, the circulation pump is required for the turbocharger afterrun cooling function.
Location
Depending on the model and equipment installed, the circulation pump (1) may be located at different positions in the engine compartment.
Shown on 2-zone automatic air conditioning |
1 | Coolant circulation pump |
P83.75-2039-82
Function requirement
Circuit 30t ON