Coolant circulation pump, function - GF83.20-P-2102-01S
WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.
Function
The quantity of coolant pumped to the rear heater core while the engine is running, depends on the coolant pump. The coolant circulation pump ensures that a uniform and bubble-free flow of water is present in the rear heater core even at low engine speeds. Actuation of the coolant circulation pump is accomplished directly by the rear air conditioning pushbutton control module.