Heater coolant shut-off valve N279 function — AUDI

Heater coolant shut-off valve
N279
function
Note
The fitting location, designation and version of
N279
A
depend on the vehicle model and equipment; note correct allocation
Electronic parts catalogue
.
At present, the
coolant shut-off valve
N82
is only fitted on vehicles with certain engines
Rep. gr.
19
Cooling system/coolant; Connection diagram - coolant hoses
. Vehicles with these engines that are equipped with auxiliary heating as an optional extra are not fitted with
N82
; this function is assumed by the
N279
A
fitted in vehicles with auxiliary heating
Auxiliary/supplementary heater
Rep. gr.
82
Coolant circuit with auxiliary/supplementary heater; Connection diagram - coolant hoses
.
To reduce noise, the holder
G
for
V50
and for
N279
A
is not bolted directly to the body. It is attached by way of bolts and rubber elements. Make sure these components do not make direct contact with the body or come into contact with other components.
With the auxiliary heater switched off, the air conditioner regulation system only activates
N279
A
(by way of the
auxiliary heater control unit
J364
) in certain air conditioner settings (e.g. in
“OFF”
mode or if maximum cooling output is required). In this case, the engine speed must be smaller than 5000 rpm, and the coolant temperature must be below 90 °C (Centigrade). If the coolant circuit to the heat exchanger of the air conditioning unit is shut off, the engine will heat up more quickly when the coolant is cold. When the auxiliary heater is switched on,
N279
A
is activated depending on e.g. the coolant temperature in the engine and in the auxiliary heater
Auxiliary/supplementary heater
Rep. gr.
82
Coolant circuit with auxiliary/supplementary heater; Connection diagram - coolant hoses
and
Vehicle diagnostic tester
in
“Guided Fault Finding”
mode.
Layout, activation and operation of the
coolant shut-off valve
N82
Chapter
“
Coolant shutoff valve
N82
function
”
.
Function of the
N279
Auxiliary/supplementary heater
Rep. gr.
82
Coolant circuit with auxiliary/supplementary heater; Removing and installing heater coolant shut-off valve
.
In the event of problems with warming of the passenger compartment in auxiliary heating mode or with the engine running, Check the incorporation of
N279
into the coolant circuit and actuation of
N279
by the
auxiliary heater control unit
J364
Chapter
“
Incorporation of front air conditioner into coolant circuit - vehicles with auxiliary heater
”
and
Vehicle diagnostic tester
in
“Guided Fault Finding”
mode.
Removing and installing
heater coolant shut-off valve
N279
Chapter
“
Removing and installing
heater coolant shut-off valve
N279
”
Removing and installing bracket
E
for
coolant circulation pump
V50
and
coolant shut-off valve
N82
/
heater coolant shut-off valve
N279
Chapter
“
Removing and installing bracket for shut-off valves
”