4 Cylinder

Coolant Recirculation Pump (V50) (Water Pump (V36))

• Depending on the version of the Climatronic control module (J255) A/C control head, coolant recirculation pump may be referred to as water pump in Guided Fault Finding. Refer to the Vehicle Diagnostic Tester in "Guided Fault Finding" function.

• The coolant recirculation pump (water pump) versions and activation differ depending on the version of the vehicle and production period. From MY 12 beginning with start of production, pumps that were controlled by a 500 Hertz signal (500 pulses per second) are being replaced by pumps that are controlled by a 100 Hertz signal depending on the engine. Pumps, controlled by a 100 Hertz signal, also have a diagnostic function and are controlled by the engine control module. Check for the correct allocation; refer to Refer to the Vehicle Diagnostic Tester in "Guided Fault Finding" function, to the and to the Parts Catalog.

• The Coolant recirculation pump can be installed in different locations. Fro vehicles with a high voltage system (hybrid vehicles) it is located between the plenum chamber bulkhead and the engine.

• The activation of the coolant recirculation pump varies. For vehicles with the high voltage system (hybrid vehicles) the activation is carried out according to the requirements of the Climatronic control module via the respective engine control module.

• For vehicles with 4 cylinders engines with the "Start/Stop System" but not having an "auxiliary heater" have a coolant recirculation pump (water pump). The coolant pump (water pump ) activation depends on the vehicle equipment level and the vehicle date of manufacture. Refer to the Vehicle Diagnostic Tester in "Guided Fault Finding" function.

• The coolant pump (water pump) - A - is installed between the engine and the plenum chamber on 4-cylinder vehicles with the "Start/Stop System" but without an "auxiliary heater".






• This illustration shows the location on a MY 10 Audi A4 with a 4 cylinder TFSI engine. The coolant pump (water pump) - A - can also be installed in a different location (for example, inside the plenum chamber) depending on the engine, vehicle model and date of manufacture.

• When the coolant pump (water pump) is working, the coolant flows through the coolant hose - B - (from the engine through the A/C heater core and coolant shut-off valve - D -) and then back to the engine through the coolant hose - C - (flow direction - arrows -).

• The coolant pump (water pump) is controlled directly when the ignition is turned on and depending on the coolant temperature and on the setting on the Climatronic control unit (J255). Refer to the Vehicle Diagnostic Tester in "Guided Fault Finding" function.

• The coolant pump (water pump) is controlled not only when the "Start/Stop System" is on, but also when the engine is running and when the temperature is set to "warm" on the Climatronic control module ("HI" appears in the display on the A/C control head and in the MMI). The coolant pump is activated to support the engine coolant pump. Check using the Vehicle Diagnostic Tester under "Guided Fault Finding".

• The Climatronic control module or the engine control model directly activates the coolant recirculation pump (water pump) and the climatronic refrigerant shut-off valve (N422) / coolant shut-off valve (N82) on vehicles with "Start/Stop" If any faults on any of the Climatronic control module components are stored, check the version, coding and adaptation. Refer to the Vehicle Diagnostic Tester under "Guided Fault Finding".