Heat Output and Temperature Door Activation Tests
Heat Output and Temperature Door Activation Tests
Test requirements are met => [ Heating Output and Temperature Door Activation, Testing Requirements ] Heating Output and Temperature Door Activation, Testing Requirements
- Close the engine hood.
- Close the doors, the engine hood, the windows, the sunroof and the rear lid.
- Open all instrument panel vents and the vents in the rear center console.
- Open the vent in the left and right B-pillars
- Close the vent for glove compartment cooling (in the glove compartment).
- Start the engine.
Set the following on the Climatronic control module (J255) :
• By pressing the SYNC button on the Climatronic control module, the settings for the front driver side are applied to the front passenger side and also on the rear A/C display control head (E265) if present.
• Press the SYNC button on the Climatronic control module.
• Select Auto mode for the driver and front passenger side (the indicator lamps in the AUTO buttons illuminate).
• Temperature preset for the driver and front passenger side set to cold (LO in the Climatronic Control Module or in the MMI display).
• The A/C compressor is switched on (the indicator lamp in the AC button comes on).
• For the fresh air blower (front and rear), preselect maximum speed (shown in the display of the Climatronic control module and of the Multi Media Interface, speed 10 or higher).
• Set the air flow direction via the rotary switches on the Climatronic control module for the driver and front passenger side to footwell and instrument panel vents (shown in the display of the Climatronic control module and of the Multi Media Interface).
Set the following on the rear A/C display control head if present:
• Auto mode (the indicator lamps in both AUTO buttons illuminate).
• Temperature preselection cold (display LO for the left and right sides).
• Preselection for the rear fresh air blower (V80) maximum speed.
• Set the air flow direction via the rotary switches on the rear A/C display control head for the left and right side to footwell and B-pillar vents (shown in the display of the rear A/C display control head).
• The indicator lamps in the AUTO buttons go out when the air flow direction and/or the fresh air blower speed is changed manually.
• The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)
• The instrument panel vents, the B-pillar vents, and the vents in the rear center console are open.
For vehicles where there is also the version with the rear air distribution housing, there is a rear Climatronic A/C display control head (E265) installed specific markets. The air temperature and the air volume calculated and regulated by the Climatronic control module is additionally influenced by the setting on the rear Climatronic A/C display control head. However, only the temperature is adjustable for this rear Climatronic A/C display control head and there is only an AUTO button, refer to => [ Rear A/C Control Head (E265) ] Rear A/C Control Head (E265).
- Initiate Guided Fault Finding of the front A/C system and select the read measured values function using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Let the A/C run a few minutes with maximum cooling output (A/C compressor is switched on, indicator lamp in the AC button comes on).
- Compare the measured value of the evaporator vent temperature sensor to the measured values of the left vent temperature sensor, right vent temperature sensor, Left footwell vent temperature sensor, right footwell vent temperature sensor (and the rear intake air temperature sensor).
• The rear intake air temperature sensor is only installed in vehicles with a rear air distributor housing (without a rear A/C display control head and without a rear A/C unit).
Target Values:
• The measured values of the temperature sensors (after the heater core) left vent temperature sensor, right vent temperature sensor, left footwell vent temperature sensor, right footwell vent temperature sensor (and the rear intake air temperature sensor) may only be a maximum of 9°C (48.2 °F) greater than the value of the evaporator vent temperature sensor after 5 minutes.
• As a result of the design of the A/C unit and the air duct in the vehicle, a certain increase in air temperature always occurs.
If the required values are not reached, perform a fault finding at a temperature increase on the evaporator.
• If the measured value in one or two temperature sensors deviates from the measured values of the other temperature sensors, check this temperature sensor and the control motor which activates the temperature door upstream from this temperature sensor using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
Then additionally in vehicles with a rear A/C display control head.
- Initiate Guided Fault Finding of the rear A/C system and select the read measured values function using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Compare the measured value of the evaporator vent temperature sensor to the measured values of the left rear upper body vent temperature sensor (G635) , the right rear upper body vent temperature sensor (G636) , the left rear footwell vent temperature sensor (G637) and the right rear footwell vent temperature sensor (G638).
Target Values:
• The displayed measured values may be a maximum of 10 °C (50 °F) greater than the displayed measured value of the evaporator vent temperature sensor.
If the required values are not reached, refer to => [ Cooling Output Of Front A/C System Is OK But Not In Rear ] Cooling Output Of Front A/C System Is OK But Not In Rear.
- Using the rotary switch on the Climatronic control module, set the temperature setting for the driver side to warm (display HI in the display of the Climatronic control module and the rear A/C display control head if present).
• If the selected temperature for the driver side on the Climatronic control module is not applied for all vents, press the SYNC button on the Climatronic control module.
• By pressing the SYNC button on the Climatronic control module, the settings for the front driver side are applied to the front passenger side and also on the rear A/C display control head if present.
The display for the preselected temperature changes for all vents (the driver and front passenger side, for the left and right rear) from LO to HI.
- Initiate Guided Fault Finding of the front A/C system and select the read measured values function using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Read the measured values of the various temperature sensors left vent temperature sensor, right vent temperature sensor, left footwell vent temperature sensor, right footwell vent temperature sensor (and rear intake air temperature sensor) displayed in the read measured values function of the Guided Fault Finding of the Climatronic control module using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• The rear intake air temperature sensor is only present in vehicles without a rear A/C display control head.
Target Values:
• The measured temperature for all temperature sensors increases to above 50 °C (122 °F) (depending on the engine temperature at the time).
• The coolant pump (V50) maintains the refrigerant flow through the heater core heater in the A/C system when the engine is not running for vehicles with a start-stop system.
• The installed location of the coolant pump varies. It is installed in the plenum chamber for most vehicles.
• The activation of the coolant pump varies. For most vehicles, the Climatronic control module (J255) is activated directly by the front Climatronic control module A/C display and control head.
The required values are achieved at all temperature sensors:
• Continuation of the test in vehicles without a rear A/C unit (with and without a rear Climatronic A/C display control head (E265) ), refer to (check the separation for the temperature control between the left and right side in the front and rear A/C unit).
• Continuation of the test in vehicles with a rear A/C unit (and a rear Climatronic A/C display control head (E265) ), refer to (check the heating output of the rear A/C unit).
• At the start of production, a rear Climatronic A/C display control head was installed only for vehicles with a rear A/C system. A different version of the rear Climatronic A/C display control head is installed for the Audi A8 hybrid without a rear A/C system (with rear air distribution housing). This version of the (E265) may be installed, depending on the version of the vehicle from MY 2013 and also the specified market and for other vehicles without a rear A/C system => [ Rear A/C Control Head (E265) ] Rear A/C Control Head (E265).
If the required values are not reached on any of the temperature sensors:
• Check the activation and function of the coolant recirculation pump (V50) (of the recirculation pump (V55) ) and of the coolant shut-off valve (N82) (of the heater coolant shut-off valve (N279) ) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the incorporation of the A/C system into the coolant circuit, refer to => [ Incorporation of A/C System in Coolant Circuit ] Incorporation of A/C System in Coolant Circuit.
• Check the ventilation of the coolant circuit.
• Check the heating output of the A/C system at an engine speed of approximately 1500 to 2000 RPM (repeat the test at a higher engine speed). If the required heating output is not reached at this engine speed, the fault is not in the A/C unit but rather in the coolant circuit (incorporation of the A/C system into the coolant circuit, engine coolant pump delivery, the coolant flowing through the heater core in the front A/C unit, incorporation of the coolant recirculation pump into the coolant circuit, etc.). Refer to => [ Incorporation of A/C System in Coolant Circuit ] Incorporation of A/C System in Coolant Circuit.
• Check the regulator for the coolant temperature in the engine (the engine coolant may not heat properly if the regulator is malfunctioning).
• Check the engine coolant pump for proper functioning (in the case of a malfunctioning coolant recirculation pump or an incorrectly incorporated coolant recirculation pump, insufficient coolant may be flowing through the heater core for the heater in the front and rear A/C unit).
If the required values are not reached at only one or two temperature sensors:
• Check the activation and function of the various control motors for the temperature doors in the front A/C unit using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the measured values of the various temperature sensors using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Perform fault finding in the case of an increase in temperature after the evaporator.
• Check the foam seal on the heater core for the heater of the front A/C unit, refer to => [ Heater Core With Front A/C Unit Installed ] Heater Core With Front A/C Unit Installed.
• Check the ventilation of the coolant circuit.
Additional testing in vehicles with a rear A/C unit (and a rear Climatronic A/C display control head (E265) ), check the heating output of the rear A/C unit.
• Continuation of the test of the heating output and the activation of the temperature doors in a vehicle with a rear A/C unit
The heating output and activation of the temperature doors of the front A/C system were tested and are OK, refer to => [ Heat Output and Temperature Door Activation Tests ].
- Read the measured values of the various temperature sensors left rear upper body vent temperature sensor, right rear upper body vent temperature sensor, left rear footwell vent temperature sensor and right rear footwell vent temperature sensor displayed in the read measured values function of the Guided Fault Finding of the rear A/C display control head using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• In addition, a commercially available thermometer can be used to measure the temperature of the air coming out of the vents in the rear center console (left and right).
Target Values:
• The measured temperature for all temperature sensors increases to above 50? (depending on the engine temperature at the time).
The required values are achieved at all temperature sensors:
• Continuation of the test (check the separation for the temperature control between the left and right side in the A/C unit).
If the required values are not reached on any of the temperature sensors:
• Check the activation and function of the coolant recirculation pump (of the recirculation pump) and of the coolant shut-off valve (of the heater coolant shut-off valve) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the incorporation of the rear A/C system into the coolant circuit, refer to => [ Incorporation of A/C System in Coolant Circuit ] Incorporation of A/C System in Coolant Circuit.
• Check the ventilation of the coolant circuit.
• Check the heating output at an engine rpm of approximately 1500 to 2000 rpm (repeat the test at a higher engine rpm). If the required heating output is not reached at this engine speed, the malfunction is not in the A/C unit but rather in the coolant circuit (check the incorporation of the A/C system in the coolant circuit, engine coolant pump delivery, the coolant flowing through the heater core in the rear A/C unit, etc.), refer to => [ Incorporation of A/C System in Coolant Circuit ] Incorporation of A/C System in Coolant Circuit.
• Check the regulator for the coolant temperature in the engine (the engine coolant may not heat properly if the regulator is malfunctioning).
• Check the engine coolant pump for proper functioning (in the case of a malfunctioning coolant recirculation pump or an incorrectly incorporated coolant recirculation pump, insufficient coolant may be flowing through the heater core for the heater in the front and rear A/C unit).
• Check the foam seal on the heater core for the heater of the rear A/C unit, refer to => [ Rear Heater Core ] Rear Heater Core.
If the required values are not reached at only one or two temperature sensors:
• Check the activation and function of the various control motors for the temperature doors in the rear A/C unit using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the measured values of the various temperature sensors in the rear air ducts using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
Continuation Of The Heating Output Test Of The Front And Rear A/C Units (Check The Separation For The Temperature Control Between The Left And Right Side In The A/C Unit)
- Via the rotary switch on the Climatronic control module (and the rear A/C display control head if present), set the temperature setting for the front passenger side (front and rear) to cold (LO in the display of the Climatronic control module (and the rear A/C display control head if present).
- The temperature setting for the driver side (front and rear) remains on warm (HI in the display of the Climatronic control module (and the rear A/C display control head if present).
- Initiate Guided Fault Finding of the front A/C system and select the read measured values function using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- Let the A/C system run for a few minutes with this setting (the A/C compressor is switched on, the indicator lamp in the AC button illuminates).
- Compare the measured values of the evaporator vent temperature sensor to the measured values of the left vent temperature sensor, the right vent temperature sensor, the left footwell vent temperature sensor, the right footwell vent temperature sensor (and the rear intake air temperature sensor).
• At the temperature setting warm for one side (the driver or front passenger side), the target outflow temperature at the evaporator is regulated to a higher value (up to approximately 10°C (50 °F)) by the Climatronic control module.
• The rear intake air temperature sensor is only present in vehicles without a rear A/C display control head.
• In vehicles without a rear A/C unit (with a rear air distributor housing), the temperature of the air flowing from the front A/C unit to the rear air distributor housing is regulated by the Climatronic control module, so that an average temperature is set for the air from the vents in the front area. The target temperature for the air from the vents in the front area is calculated via the setting for the left and right side on the Climatronic control module by the Climatronic control module. However, if a setting which no longer regulates the temperature (for example HI for maximum heating or LO for maximum cooling) is present on the Climatronic control module, the temperature of the air from the vents in the front area is no longer regulated. If, for example, maximum heating HI is set on the Climatronic control module for one side and maximum cooling LO for the other side, the air for the vents in the front area is maximally heated.
• For vehicles where there is also the version with the rear air distribution housing, there is a rear Climatronic A/C display control head (E265) installed for specific markets. The air temperature and the air volume calculated and regulated by the Climatronic control module (J255) is additionally influenced by the setting on the rear Climatronic A/C display control head. However, only the temperature is adjustable for this rear Climatronic A/C display control head and there is only an AUTO button, refer to => [ Rear A/C Control Head (E265) ] Rear A/C Control Head (E265).
Target values:
• On the left vent temperature sensor and left footwell vent temperature sensor, the temperature remains above 50°C (122 °F) (depending on the current engine temperature).
• On the right vent temperature sensor and right footwell vent temperature sensor, the temperature drops to a value which may be a maximum of 15°C (59 °F) higher than the measured value of the evaporator vent temperature sensor within 5 minutes.
• A temperature which corresponds approximately to the temperature on the warmer side is set on the rear intake air temperature sensor (disregard).
• The temperatures of the temperature sensors on one side (left vent temperature sensor and left footwell vent temperature sensor) and (right vent temperature sensor and right footwell vent temperature sensor) displayed in the read measured values function of the Guided Fault Finding equalize within 5 minutes (the particular temperature difference is less than 9°C (48 °F)).
• The coolant pump (V50) maintains the refrigerant flow through the heater core heater in the A/C system when the engine is not running for vehicles with a start-stop system.
• The installed location of the coolant pump varies. It is installed in the plenum chamber for most vehicles.
• The activation of the coolant pump varies. For most vehicles, the Climatronic control module (J255) is activated directly by the front Climatronic control module A/C display and control head.
- In the case of vehicles without a rear A/C display control head, set the temperature setting to 18°C (64 °F) for the front passenger side and to 28°C (82 °F) for the driver side.
• A temperature between the values for the left and right is set on the rear intake air temperature sensor (the air for the left and right side from the front A/C unit mixes in the rear air distributor housing).
- Initiate Guided Fault Finding of the rear A/C system (if present) and select the read measured values function using in the "Guided Fault Finding" function.
- Compare the measured value of the evaporator vent temperature sensor to the measured values of the left rear upper body vent temperature sensor, the right rear upper body vent temperature sensor, the left rear footwell vent temperature sensor and the right rear footwell vent temperature sensor.
Target Values:
• The temperature on the left rear upper body vent temperature sensor and left rear footwell vent temperature sensor remains higher than 50°C (122 °F) (depending on the current engine temperature).
• On the right rear upper body vent temperature sensor and right rear footwell vent temperature sensor, the temperature drops to a value which is a maximum of 15°C (59 °F) higher than the measured value of the evaporator vent temperature sensor within 5 minutes.
• The temperatures of the temperature sensors on one side (left rear upper body vent temperature sensor and left rear footwell vent temperature sensor) and (right rear upper body vent temperature sensor and right rear footwell vent temperature sensor, right footwell vent temperature sensor) displayed in the read measured values function of the Guided Fault Finding equalize within 5 minutes (the particular temperature difference is less than 9°C (48 °F)).
If the target values are reached, the test is complete.
• If the temperature for the driver side is set to LO and the temperature for the front passenger side is set to HI, this test can be performed again using opposite measured values.
If the specified values are not reached, check the following:
• Check the activation and function of the various control motors for the temperature doors in the front or rear A/C unit (depending on where the target values were not reached) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the foam seal on the heater core for the heater of the front or rear A/C unit (depending on where the target values were not reached), refer to => [ Heater Core With Front A/C Unit Installed ] Heater Core With Front A/C Unit Installed and => [ Rear Heater Core ] Rear Heater Core.
• Check the ventilation of the coolant circuit.
• Check the activation and function of the coolant recirculation pump (of the recirculation pump) and of the coolant shut-off valve (of the heater coolant shut-off valve) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Check the engine coolant pump for proper functioning (in the case of a malfunctioning coolant recirculation pump or an incorrectly incorporated coolant recirculation pump, insufficient coolant may be flowing through the heater core for the heater in the front and rear A/C unit).
• Check the incorporation of the A/C system into the coolant circuit, refer to => [ Incorporation of A/C System in Coolant Circuit ] Incorporation of A/C System in Coolant Circuit.
Fault Finding In The Case Of A Temperature Increase Downstream From The Evaporator (In The Front A/C Unit)
