Checking heating output and activation of temperature flaps - "“deluxe”" version — AUDI

🧭 Before you start

Fits: Audi A6/A7 C7 (4G, 2011–2018); platform code 4X

• Renewed: defective sender

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• Pressing the SYNC button (10) on J255 stores the settings for the front driver's side at the front passenger's side as well and at E265.
• On account of the design of the air conditioning unit and the air routing in the vehicle there is always a certain increase in the temperature of the air as it is conveyed from the evaporator to the vents.
• If the temperature selected for the driver's side on J255 is not adopted for all vents, press the SYNC button on J255 again.
• Use can additionally be made of a commercially available thermometer to measure the temperature of the air emerging from the rear centre console vents (on the left and right).
• After setting the temperature for the driver's side to "“cold”" and for the passenger's side to "“warm”", this test can be repeated with the opposite measured values.

📋 Procedure

1. ⚠ When working on a vehicle with the ignition switched on or while the drive system is active, the engine can start unexpectedly and exhaust fumes can cause a health hazard in closed rooms. Moving parts can trap or draw in parts of the body and/or clothing (safety hazard). Before switching on the ignition, perform the following steps:Move selector lever to position PActivate parking brake Switch off ignitionOpen bonnetConnect battery charger (e.g. VAS 5095A) to jump-start connections of 12 V electrical system Switch on ignition — To minimise the number of automatic engine starts when the vehicle's drive system is active during test and measurement work, charge the vehicle batteries e.g. with the battery charger 60AVAS 5904 in battery standby mode Electrical system; General information27Battery; Charging battery and Electrical system, hybrid93General warning instructions for work on the high-voltage system.
2. For test and measurement work that requires the vehicle's drive system to be active or the ignition to be switched on, move the selector lever to position "“P”", activate the parking brake and arrange the tools needed so that they cannot come into contact with moving components of the engine and so that they cannot even come near to components that turn when the engine is running. [Note: Also move the selector lever to position "“P”" and activate the parking brake before performing test and measurement work for which the ignition must be switched on but where the vehicle's drive system does not need to be active.The status of the drive system (READY) is shown by the control unit in dash panel insert J285 via the "“power meter”"Owner's Manual.Activating and deactivating drive system Owner's Manual (note display of control unit in dash panel insert J285).]
3. Activate drive system/READY (observe display in control unit in dash panel insert J285) Owner's Manual.
4. Close bonnet.
5. Close doors, bonnet, windows, sun roof and rear lid.

6. Open all the dash panel vents and the vents in the rear centre console.
7. Open the vents in the B-pillars.
8. Close the vent for glove compartment cooling in the glove compartment.
9. Switch on ignition and activate drive system (READY); engine starts automatically if required (on vehicles with start/stop system and vehicles with high-voltage system).
10. Start engine (not on vehicles with high-voltage system). [Note: Pressing the SYNC button (10) on J255 stores the settings for the front driver's side at the front passenger's side as well and at E265.] [Note: The lamps in the two AUTO buttons go out when the air outflow direction and/or the fresh air blower speed is/are altered manually.The maximum possible fresh air blower speed depends on several factors (electrical system voltage etc.).Dash panel vents, as well as vents in B-pillars and in rear centre console open.]
11. Select air conditioner "“Read measured values”" function on J255 in "“Guided Fault Finding”" mode.
12. Run the air conditioner for several minutes at maximum cooling output.
13. Compare the measured value of G263 to the measured values of G150, G151, G261 and G262. [Note: On account of the design of the air conditioning unit and the air routing in the vehicle there is always a certain increase in the temperature of the air as it is conveyed from the evaporator to the vents.] [Note: If the measured value for one or two temperature sensors differs from the measured values of the other temperature sensors, check this temperature sensor and the control motor which actuates the temperature flap upstream of this temperature sensor in "“Guided Fault Finding”" mode.]
14. Terminate air conditioner "“Guided Fault Finding”" on J255 and on the rear Climatronic operating unit E265 select "“Read measured values”" function in "“Guided Fault Finding”" mode.
15. Compare the previously determined measured value of G263 to the measured values of G635, G636, G637 and G638.
16. Use the rotary switches (1, 5) on the operating unit, Climatronic control unit J255 to set the temperature for the driver and passenger side to "“warm”".
17. Press the SYNC button (10) on J255. [Note: If the temperature selected for the driver's side on J255 is not adopted for all vents, press the SYNC button on J255 again.]
18. Select air conditioner "“Read measured values”" function on J255 in "“Guided Fault Finding”" mode.
19. Read off the measured values displayed for the various temperature sensors G150, G151, G261 and G262. [Note: On vehicles with no coolant circulation pump V50/ circulation pump V55, it may be necessary to increase the engine speed slightly to approx. 1400 rpm to obtain the required coolant throughput through the heating system heat exchanger in the air distribution housing.On vehicles with start/stop system and vehicles with high-voltage system, reduce the speed of the fresh air blower V2 if applicable. With the engine stopped and maximum fresh air blower speed, the delivery of the coolant circulation pump V50 may not always be sufficient to attain the required heat output.On vehicles with start/stop system and vehicles with high-voltage system, the flow of coolant through the heating system heat exchanger in the air conditioning unit is maintained by the coolant circulation pump V50 when the engine is stopped.]
20. Set the air distribution at E265 by way of the button (4) such that roughly the same volume of air flows out of the vents in the B-pillars and the rear centre console – display (1) of E265.
21. Read off the measured values displayed in the "“Read measured values”" function for the various temperature sensors G635, G636, G637 and G638 in "“Guided Fault Finding”" mode. [Note: Use can additionally be made of a commercially available thermometer to measure the temperature of the air emerging from the rear centre console vents (on the left and right).] [Note: On vehicles with no coolant circulation pump V50/ circulation pump V55, the engine speed has to be increased slightly to approx. 1400 rpm to obtain the required coolant throughput through the heating system heat exchanger in the air distribution housing.On vehicles with start/stop system and vehicles with high-voltage system, reduce the speed of the fresh air blower V2 if applicable. With the engine stopped and maximum fresh air blower speed, the delivery of the coolant circulation pump V50 may not always be sufficient to attain the required heat output.] [Note: As the air cooled by the air conditioning unit has to flow through the air duct under the centre console to the rear, it may be some time before the air at the rear vent attains the required values.If the required temperature is not attained at one temperature sensor, alter the setting at E265 so that more air flows past this temperature sensor.]
22. Use the rotary switches on the operating unit, Climatronic control unit J255 and the rear Climatronic operating unit E265 to set the temperature for the passenger side (front and rear) to "“cold”".
23. Leave the temperature setting for the driver side (front and rear) on "“warm”".
24. Terminate "“Guided Fault Finding”" for E265 and on the Climatronic control unit J255 select the "“Read measured values”" function in "“Guided Fault Finding”" mode.
25. Run the air conditioner for several minutes in this setting.
26. Compare the measured value of the evaporator output temperature sender G263 to the measured values of G150, G151, G261 and G262. [Note: If the temperature setting for one side (driver's or passenger's side) is "“warm”", the specified output temperature at the evaporator is regulated by the operating unit, Climatronic control unit J255 to a higher value (up to approx. 10 °C).Even with a rear Climatronic operating unit E265, the temperature of the air flowing out of the rear vents is regulated by the operating unit, Climatronic control unit J255.]
27. Note down the measured value of the evaporator output temperature sender G263.
28. Terminate air conditioner "“Guided Fault Finding”" on J255 and on the rear Climatronic operating unit E265 select "“Read measured values”" function in "“Guided Fault Finding”" mode.
29. Compare the measured value of G263 to the measured values of G635, G636, G637 and G638. [Note: After setting the temperature for the driver's side to "“cold”" and for the passenger's side to "“warm”", this test can be repeated with the opposite measured values.]
30. Pinch off the two coolant hoses to the heat exchanger of the front air conditioning unit using hose clamps 3093 for example .
31. Repeat checking of the heat output and actuation of the temperature flaps with "“LO”" set on the front and rear operating unit .
32. Compare the measured value of the evaporator output temperature sender G263 to the measured values of G150, G151, G261 and G262 (note permissible difference) .
33. Compare the measured values of G635, G636, G637, G638 to the previously measured value of the evaporator output temperature sender G263 (note permissible difference) .
34. Do the measured values of the temperature sensors coincide with the coolant hoses pinched off and are the required values attained (note permissible difference) ?
35. Detach the hose clamps 3093 from the two coolant hoses.
36. Check the sender supplying the deviating measured value for correct installation, as well as the electrical connections for contact resistance in "“Guided Fault Finding”" mode .
37. Check the actuation and operation of the temperature flap control motor V158 / V159 and the rear temperature flap control motor V313 / V314 as well as actuation of the corresponding temperature flap Air routing in air intake unit and air conditioning unit.
38. Eliminate cause of incorrect measured value; renew defective sender if necessary.
39. Check operation of the temperature flap producing the temperature increase Exploded view - flaps and partitions in air distribution housing.
40. Check the heat output and actuation of the temperature flaps again Checking heating output and activation of temperature flaps - "deluxe" version.
41. Eliminate the cause of the malfunction in "“Guided Fault Finding”" mode and
42. Check the heat output and actuation of the temperature flaps again Checking heating output and activation of temperature flaps - "deluxe" version.

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