Heating Shutoff Valve, Component Description - Mercedes-Benz OM 471 Introduction Into Service Manual

System components
GF83.20>W>3126H
MODEL 963, 964
Location
Y49 Heater shutoff valve
The heater shutoff valve (Y49) is located on
the left next to the fresh air intake on the
heater blower unit.
Task
The heater shutoff valve (Y49) blocks the
coolant supply to the heater heat
exchanger if heat output is not required
(temperature control flaps set to cold).
Function in vehicles with code (D6M) Hot water auxiliary heater,
cab or code (D6N) Hot water auxiliary heater, cab and engine
The auxiliary heater only heats the coolant in the cooling circuit of
the heater heat exchanger when the heating shutoff valve is
closed (Y49). To avoid frequent switching on and off of the
auxiliary heater, the heater shutoff valve (Y49) is intermittently
opened so that coolant continues to flow from the engine cooling
circuit.
168

Heating shutoff valve, component description

– This printout will not be recorded by the update service. Status: 09 / 2011 –
20.7.11
W83.20>1104>05