Layout, activation and operation of coolant circulation pump V50 (coolant pump V36) - vehicles with 4-cyl. or 6-cyl. engine — AUDI

Layout, activation and operation of
coolant circulation pump
V50
(
coolant pump
V36
) - vehicles with 4-cyl. or 6-cyl. engine
Layout on vehicles with a 4-cyl. engine and on certain vehicles with a 6-cyl. engine
Note
V50
can be fitted in different locations. On most vehicles with a 4-cyl. engine and certain vehicles with a 6-cyl. engine, it is located between the plenum chamber partition panel and the engine. Different fitting location in vehicles with a 6-cyl. engine
Chapter
Depending on the version of the air conditioner operating and display unit (
Climatronic control unit
J255
), the
coolant circulation pump
V50
may also be referred to as
coolant pump
V36
in the Guided Fault Finding routine
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
.
The version of the
coolant circulation pump
V50
(
coolant pump
V36
) and the activation of the pump(s) differ depending on the vehicle version and production period. From model year 2012 onwards and depending on the engine, the pumps fitted from the start of production onwards and activated via a 500 hertz signal (500 pulses per second) are gradually being replaced by pumps activated via a variable signal (100 ... 500 hertz). The pumps activated via a variable signal are equipped additionally with a diagnostic function and are generally activated via the corresponding engine control unit. Therefore it is important to observe the correct assignment (only the assigned pump can be activated)
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
,
Current flow diagrams, Electrical fault finding and Fitting locations
and
Electronic parts catalogue
.
V50
can be fitted in different locations. On vehicles with a high-voltage system (hybrid vehicles) it is located between the plenum chamber partition panel and the engine.
The activation of
V50
differs. On vehicles with a high-voltage system (hybrid vehicles), activation occurs after a request from
J255
via the corresponding engine control unit
Current flow diagrams, Electrical fault finding and Fitting locations
.
Vehicles with a 4-cyl. engine and with the start/stop system (optional extra), but without an auxiliary heater (optional extra), are fitted with
V50
(
V36
)
Rep. gr.
19
Coolant pump/thermostat assembly
. Activation of
V50
(
V36
) depends on vehicle equipment and production period
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
and
Current flow diagrams, Electrical fault finding and Fitting locations
.
Vehicles with a 4-cyl. engine and with the start/stop system (optional extra), but without an auxiliary heater (optional extra), are fitted with a
coolant circulation pump
V50
(
V36
)
A
e.g. in the area between the engine and the plenum chamber partition panel
Rep. gr.
19
Coolant pump/thermostat assembly
.
This illustration shows the layout on an Audi A4 with a 4-cyl. TFSI engine (model year 2010). Depending on the engine, vehicle model and production period, the
coolant circulation pump
V50
(
coolant pump
V36
)
A
may also be installed at a different location (e.g. in the plenum chamber)
Rep. gr.
19
Coolant pump/thermostat assembly
.
When
V50
(
V36
) is running, coolant is drawn in through coolant hose
B
(from the engine through the heat exchanger of the air conditioning unit and the coolant shut-off valve
D
) and conveyed through coolant hose
C
back to the engine (note direction of flow
arrows
).
Depending on the coolant temperature and the setting on the air conditioner operating and display unit (
Climatronic control unit
J255
),
V50
(
V36
) is activated directly by the operating and display unit when the ignition is on
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
and
Current flow diagrams, Electrical fault finding and Fitting locations
.
Depending on the vehicle model,
V50
(
V36
) is not only activated when the
“stop function”
is active, but also when the engine is running, e.g. when the temperature is preset to
“warm”
on the air conditioner operating and display unit (
Climatronic control unit
J255
) (
“HI”
displayed on air conditioner operating and display unit and Multi Media Interface). The
coolant circulation pump
V50
is then activated to support the engine's coolant pump
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
.
On vehicles with a start/stop system,
V50
(
V36
) and the
Climatronic coolant shut-off valve
N422
/
coolant shut-off valve
N82
are activated directly by the air conditioner operating and display unit (
Climatronic control unit
J255
) or by the corresponding engine control unit. If faults are detected at these components in the air conditioner operating and display unit (
Climatronic control unit
J255
), you must therefore observe the correct version, coding and adaption of the
J255
Vehicle diagnostic, testing and information system VAS 5051 ("Guided Fault Finding")
.
Vehicles with auxiliary heater (optional equipment) are not fitted with
N422
/
N82
or
V50
(
V36
). On these vehicles the components of the auxiliary heater (
heater coolant shut-off valve
N279
and
circulation pump
V55
) assume this function
Auxiliary/supplementary heater
Rep. gr.
82
Overview of fitting locations - auxiliary/supplementary heater; Overview of fitting locations - components not located in passenger compartment
.