audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
Mode of operation of air quality sensorG238 and humidity sender in fresh air intake duct G657 > < Coolant circulation pumpV50 (coolant pumpV36) on vehicles with a 4-cyl. engine

A4 Mk3

Coolant circulation pumpV50 (coolant pumpV36) on vehicles with a 6-cyl. petrol engine
Coolant circulation pump -V50- (coolant pump -V36-) on vehicles with a 6-cyl. petrol engine
  Note
t  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 → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  The design of the coolant circulation pump -V50- (coolant pump -V36-) and pump actuation differ depending on the vehicle model and production period. As of Model Year 2012 and depending on the engine, the pumps fitted as of the start of production and actuated by way of a 500 hertz signal (500 pulses per second) are gradually being replaced by pumps actuated by way of a 100 hertz signal. The pumps actuated by way of a 100 hertz signal additionally feature a diagnostic function and are generally actuated by way of the corresponding engine control unit. Attention is therefore to be paid to correct assignment (only the assigned pump can ever be actuated) → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051, → Current flow diagrams, Electrical fault finding and Fitting locations and → Electronic parts catalogue.
t  On vehicles with a 6-cyl. FSI engine (currently not available for 6-cyl. TFSI engine) and with other engines with certain optional extras (e.g. vehicles with a „start/stop system“) but with no „auxiliary heater“ optional extra are fitted with -V50- (-V36-) → Engine, mechanics; Rep. gr.19. Actuation of -V50- (-V36-) depends on the vehicle equipment and production period → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051. and → Current flow diagrams, Electrical fault finding and Fitting locations.
   
t  On vehicles with a 6-cyl. FSI engine with no „auxiliary heater“ as optional extra, -V50- (-V36-) -A- is fitted for example in the area between the engine and the right longitudinal member beneath the right headlight. This illustration shows the layout on an Audi A5 Coupé with a 6-cyl. FSI engine. The layout of the components may differ on the Audi A5 Sportback, Audi A4, Audi Q5 etc. or on vehicles with a different engine → Engine, mechanics; Rep. gr.19.
t  When -V50- (-V36-) is running, the coolant is drawn in via the coolant hose -B- (from the engine) and conveyed via the coolant hose -C- to the heat exchanger in the air conditioning unit (heed the direction of flow -arrows-).
t  Depending on the production period, -V50- (-V36-) is actuated via the circulation pump relay -J160- (via the same output as the Climatronic coolant shut-off valve -N422-) or - with gradual introduction as of Model Year 2009 - directly by the air conditioner operating and display unit, Climatronic control unit -J255- → Current flow diagrams, Electrical fault finding and Fitting locations and → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  On vehicles with a circulation pump relay -J160- (e.g. Model Year 2008 vehicles), -V50- (-V36-) is always actuated with the ignition switched on if the Climatronic coolant shut-off valve -N422- is not being actuated (e.g. in the „Warm“ temperature setting on the air conditioner operating and display unit, Climatronic control unit -J255-) → Current flow diagrams, Electrical fault finding and Fitting locations and → Chapter.
t  On vehicles with no circulation pump relay -J160- (gradual introduction as of Model Year 2009), -V50- (-V36-) is actuated directly by the air conditioner operating and display unit, Climatronic control unit -J255- with the ignition switched on depending on the coolant temperature and the setting on the operating and display unit → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051 and → Current flow diagrams, Electrical fault finding and Fitting locations.
t  Depending on the vehicle model, -V50- (-V36-) is actuated not only with the „Stop function“ active (gradual introduction as optional extra as of Model Year 2010) but also with the engine running e.g. with „warm“ temperature setting on the air conditioner operating and display unit, Climatronic control unit -J255- („HI“ display on air conditioner operating and display unit and Multi Media Interface). The coolant circulation pump -V50- is then actuated to assist the engine coolant pump → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  On vehicles on which -V50- (-V36-) and the Climatronic coolant shut-off valve -N422- are actuated directly by the air conditioner operating and display unit, Climatronic control unit -J255-, faults at these components are stored in the air conditioner operating and display unit, Climatronic control unit -J255-. Attention is therefore to be paid to the version, encoding and adaption of -J255- → "Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
t  Vehicles with an „auxiliary heater“ as optional extra are not fitted with a Climatronic coolant shut-off valve -N422- or -V50- (or -V36-). On these vehicles, this function is assumed by the components of the auxiliary heater (heater coolant shut-off valve -N279- and circulation pump -V55-) → Auxiliary heater; Rep. gr.82.
  A87-10585

Mode of operation of air quality sensorG238 and humidity sender in fresh air intake duct G657 > < Coolant circulation pumpV50 (coolant pumpV36) on vehicles with a 4-cyl. engine