Connection diagram - coolant hoses, vehicles without non-return valve — AUDI

Connection diagram - coolant hoses, vehicles without non-return valve
Note
The
arrows
indicate the direction of coolant flow. With the
heater coolant shut-off valve
N279
actuated (e.g. in auxiliary heating mode). With cold coolant and the ignition switched off, the coolant is drawn in directly from the heat exchanger of the air conditioning unit by the
circulation pump
V55
.
Bleed coolant circuit
Rep. gr.
19
Cooling system/coolant; Draining and filling cooling system
and
Chapter
.
For information on components not mentioned here, refer to
Rep. gr.
19
Cooling system/coolant; Connection diagram - coolant hoses
.
Incorporation of air conditioner into coolant circuit
Heating, air conditioning
Rep. gr.
87
Heater and air conditioning unit (front)
.
Auxiliary heater
Removing and installing
Chapter
Coolant return to engine
Incorporation of air conditioner into coolant circuit
Heating, air conditioning
Rep. gr.
87
Heater and air conditioning unit (front)
and
Rep. gr.
19
Cooling system/coolant; Connection diagram - coolant hoses
Heater coolant shut-off valve
N279
Activated in auxiliary heating mode by
auxiliary heater control unit
J364
.
Removing and installing
Chapter
Checking wiring
“Guided Fault Finding”
function of
vehicle diagnostic, testing and information system
VAS 5051/
and
Current flow diagrams, Electrical fault finding and Fitting locations
Operation
Chapter
Different versions (for Audi A5 Coupé, Audi A4 and Audi Q5); note correct assignment
Electronic parts catalogue
.
Note
Depending on the vehicle model, the engine fitted, the coolant temperature and the setting on the operating and display unit,
Climatronic control unit
J255
,
N279
may also be actuated by the
auxiliary heater control unit
J364
with the auxiliary heater switched off. In this case, the activation is a response to a request from the operating and display unit (
Climatronic control unit
J255
) via the data bus
Heating, air conditioning
Rep. gr.
87
Operating and display unit
.
On the Audi Q5,
N279
can only be activated up to a certain engine speed (currently up to approx. 1200 rpm). Therefore it is important to make sure that that version, coding and adaption of the auxiliary heater are correct
“Guided Fault Finding”
function of
vehicle diagnostic, testing and information system
VAS 5051/
.
There are different versions of
N279
(with 3 or 4 connections for coolant hoses). On the version with 4 connections, one connection is sealed with a cap.
Heat exchanger in air conditioning unit
Incorporation of air conditioner into coolant circuit
Heating, air conditioning
Rep. gr.
87
Heater and air conditioning unit (front)
and
Rep. gr.
19
Cooling system/coolant; Connection diagram - coolant hoses
Coolant supply from engine
Incorporation of air conditioner into coolant circuit
Heating, air conditioning
Rep. gr.
87
Heater and air conditioning unit (front)
and
Rep. gr.
19
Cooling system/coolant; Connection diagram - coolant hoses
Circulation pump
V55
The
circulation pump
V55
is incorporated into the auxiliary heater hoses.
Removing and installing
Chapter
Note
From model year 2010 onwards, a start/stop system (optional equipment) is offered for this vehicle in combination with certain engines. On these vehicles, pay attention to the correct version of the air conditioner operating and display unit,
Climatronic control unit
J255
and of the auxiliary heater
Electronic parts catalogue
and
"Guided Fault Finding" function of vehicle diagnostic, testing and information system VAS 5051
.
On vehicles with a start/stop system, the
circulation pump
V55
of the auxiliary heater is activated by the
auxiliary heater control unit
J364
while the stop function is active. Via the data bus,
J364
is requested by the air conditioner operating and display unit,
Climatronic control unit
J255
to switch on
V55
"Guided Fault Finding" function of vehicle diagnostic, testing and information system VAS 5051