Duovalve, function - GF83.20-P-2100-01B

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

When the heat requirement is low the pushbutton control module switches the duovalve solenoids to ground, the solenoids pull in and block the coolant flow to the right and left sides of the heater core separately.

At the maximum temperature setting the pushbutton control module interrupts the ground connection, current no longer flows through the solenoids, and the coolant flow through the heater core is at its maximum.

During normal regulation the pushbutton control module completes and interrupts the circuit to ground intermittently. The closing and opening times for the duovalves depend on the deviation between the temperature present on the interior sensor and that set on the pushbutton control module.

Residual engine heat utilization

Control of the interior temperature in the residual engine heat utilization mode is the same as when the vehicle is moving, the coolant circulation pump circulates the coolant.