Heating Output and Temperature Door Activation, Testing Requirements
Heating Output and Temperature Door Activation, Testing Requirements
With high voltage systems (hybrid vehicles)
Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system.
If it is necessary for the following procedure to perform work in the vicinity of high voltage components, perform a visual inspection of the high voltage components and cables for damages, refer to => [ Visual Inspection of High-Voltage Components and Cables for Damage ] Visual Inspection of High-Voltage Components and Cables For Damage and always follow the warnings when working on the high voltage system.
Risk of unintended engine start
The ignition must be turned off and the ignition key must remain outside of the vehicle when working on vehicles with a high voltage system.
How to handle high voltage cable:
• Do not stand on or place tools on high voltage cables and their components as it may damage the cable insulation.
• Never bend or kink high voltage cables forcefully as it may damage the cable insulation.
• Color-code the round high voltage connector with an external color ring and code them mechanically using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid mechanically damaging the high voltage connector.
There is a risk of electrocution from damaged high voltage components
Observe the following when working around high voltage components and high voltage wires:
• Never work around high voltage components and cables with cutting, deformed, or sharp edged tools, or heat sources such as welding or soldering tools, heated air, and thermal glue.
• Inspect the high voltage components visually before beginning.
• Perform a visual inspection of the electric drive power and control electronics (JX1) , the electro-drive drive motor (V141) , the A/C compressor (V470) and the high voltage lines when working in the engine compartment.
• Perform a visual inspection of the high voltage lines and the cover when working on the underbody.
• Perform a visual inspection of the high voltage lines and the Electrobox with the high voltage system maintenance connector (TW) when working in the luggage compartment.
• Perform a visual inspection on all of the potential equalization cables.
Observe the following items when performing the visual inspection:
• The components do not display any signs of external damage.
• The high voltage cable insulation and the potential equalization cables are not damaged.
• The high voltage cables do not display any abnormal deformations.
• Every high voltage component is marked with a red warning label.
Working on a high voltage system when activated or with the ignition turned on
The engine may start unexpectedly when performing work while the ignition is turned on or when the ready mode is activated and may cause poisoning in enclosed spaces. Be aware of body limbs and/or clothing when clamping or pulling.
Perform the following steps before turning on the ignition:
• Move the selector lever into position P
• Activate the parking brake
• Switch off ignition.
• Open the engine hood
• Connect the charging unit, such as battery charger (VAS 5093) to the battery jump start terminal for the 12V vehicle electrical system
• Switch on the ignition
- Charge the vehicle battery using the (VAS 5903) in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active.
- Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.
• Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active.
• The ready mode is displayed in the instrument cluster control module (J285) above the "power meter". Refer to the Owner's Manual.
• Activate and deactivate the ready mode. Refer to the Owner's Manual (consult the display in the instrument cluster control module).
All vehicles
• From 01.2008, A/C units which have an additional connection for the glove compartment cooling are being installed. On vehicles without glove compartment cooling, this connection is sealed with a plug. Refer to => [ Glove Compartment Cooling to Air Intake Manifold Connection ] Glove Compartment Cooling to Air Intake Manifold Connection. If the plug or the air guide are not installed correctly, then cold air will be guided into the passenger footwell and the customer will complain about poor heating performance on the passenger side.
• Coolant circuit has been bled according to specifications.
• The engine is warm (the coolant temperature is higher than 80 °C (176 °F)).
• Radiator and condenser are clean (if necessary clean)
• All air ducts, covers and seals OK and properly installed
• Air flow through dust and pollen filter not obstructed by dirt. Refer to => [ Dust and Pollen Filter ] Service and Repair.
• Air intake apparatus (in fresh air and recirculating air mode) is not impaired by soiling or components installed as retrofit.
• The glove compartment cooling connection is sealed with a plug (on vehicles without the option "glove compartment cooling") or the air guide into the glove compartment is installed to specification (on vehicles with the option "glove compartment cooling"). Refer to => [ Glove Compartment Cooling to Air Intake Manifold Connection ] Glove Compartment Cooling to Air Intake Manifold Connection.
• Vehicle not exposed to sunlight
• Climatronic Control Module (J255) DTC memory was checked and erased, basic setting was performed and the Climatronic control module. coding was checked using the Vehicle diagnostic tester in "Guided Fault Finding".
• The Climatronic Control Module adaptation was checked using the Vehicle diagnostic tester in "Guided Fault Finding".
• All instrument panel vents open
• The hood is closed.
With high voltage systems (hybrid vehicles)
• The ignition is turned on and the ready mode is active, the engine runs or starts only, when heated refrigerant is necessary to reach the temperature setting in the vehicle interior or for example the traction battery (A2) (hybrid battery) has not been charged enough.
• With the ignition turned on and the temperature preselect "warm" on the Climatronic control module ("HI" in the display and control head and in the MMI display).
For vehicles without a high voltage system
• The engine is running.
• With the engine running and the temperature preselect "warm" on the Climatronic control module ("HI" in the display and control head and in the MMI display).
All vehicles
• When the engine is running (ready mode is active for vehicles with a high voltage system) and the temperature preset is set to "warm" on the Climatronic control module (display "HI" in the display for the A/C system control head and the Multi Media Interface).
- This is not activated on vehicles with a climatronic refrigerant shut-off valve (N422) / coolant shut-off valve (N82) (not installed on all vehicles). Refer to => [ Coolant Recirculation Pump (V50) (Water Pump (V36)) ] Coolant Recirculation Pump (V50) (Water Pump (V36)).
- This is actuated on vehicles with a coolant pump (water pump) (not on all vehicles, installed, for example, on the 6 cylinder FSI vehicles and on vehicles having the Start/Stop System but without an "auxiliary heater" and on high voltage vehicles) Refer to => [ Coolant Pump ] Coolant Pump.
Set the "Basis" Climatronic control module as follows:
• "Auto" operating mode (indicator light on the AUTO button lights up).
• Temperature preselect "cold" (display"LO" in the MMI display).
• The A/C compressor is on (the indicator lamp on the AC button comes on).
• Preselect for the fresh air blower "maximum speed" (in the Multi Media Interface display, level "10" or greater).
The "Comfort" Climatronic Control Module is set as follows:
• "Auto" mode (the indicator lamp in both AUTO buttons illuminate).
• Temperature preselect "cold" for the driver's and passenger's side (display "LO" for the driver's and passenger's side in the A/C Control Head display and in the Multi Media Interface display).
• The A/C compressor is on (the indicator lamp on the AC button comes on).
• Preselect for the fresh air blower "maximum speed" (display in the A/C Control Head and in the Multi Media Interface display, level "10" or greater).
• The indicator lamp in the or both AUTO button(s) goes out when the fresh air blower speed is changed manually.
• The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)
- On vehicles equipped with the "Comfort" A/C system, the Rear Temperature Selection Potentiometer (G538) is set to "cold" (installed in the rear center console vent).
- On vehicles equipped with the "Comfort" A/C system, the vent the rear center console is open.
- The activation and function of the auxiliary heater is OK on vehicles with a gasoline engine with an auxiliary heater.
• Check the activation and function of the auxiliary heater on vehicles with an auxiliary air heater heating element (Z35) if the complaint is that the heating output is insufficient when the outside air temperatures are low. Refer to => [ Auxiliary Heater Heating Element (Z35), Testing ] Testing and Inspection.
• As a running change in MY 10, gasoline engines that can run on bioethanol (Flex Fuel Vehicles) were introduced, which currently have an auxiliary heater heating element. Refer to => [ Auxiliary Heater Heating Element (Z35), Testing ] Testing and Inspection.
• Currently an auxiliary air heater heating element is installed for vehicles with a high voltage system (hybrid vehicles) and a gasoline engine => [ Auxiliary Heater Heating Element (Z35), Testing ] Testing and Inspection.
Functions when the engine is running (non hybrid vehicles) / drive ready mode activated (hybrid vehicles):
• For vehicles with the high voltage system (hybrid vehicles) and for vehicles with the start stop system, the engine only runs potentially when an additional heat output is needed to reach the set temperature.
- The coolant fan ( coolant fan (V7) and coolant fan 2 (V177) ) run (activation and speed depend on pressure in coolant circuit and engine temperature).
• Depending on the version of the Climatronic control module, the coolant fan and coolant fan 2 are only switched on at a certain pressure in the coolant circuit (currently, at a pressure of approximately 9 bar (130 psi)). The coolant fan(s) control is displayed in the measured values block. Refer to the Vehicle diagnostic tester in "Guided Fault Finding".
- The Fresh Air Blower (V2) runs with maximum speed ("10" or greater).
• The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)
- The A/C goes into recirculating air mode for approximately 1 minute after starting the engine (after activating the ready mode on high voltage vehicles) the back pressure/fresh air door is closed and the recirculation door is opened, fresh air door (V2) extracts the air from passenger compartment below instrument panel / glove compartment.
• If one of these requirements is not filled, check the DTC memory, perform output diagnostic test mode and read the measured values block using the Vehicle diagnostic tester in "Guided Fault Finding".
If the above mentioned requirements are fulfilled:
• Check the heating output and temperature door activation (on the "Basis" A/C system). Refer to => [ Heating Output and Temperature Door Activation, Checking, Basis ] Heating Output and Temperature Door Activation, Checking, Basis.
• Check the heating output and temperature door activation (on the "Comfort" A/C system). Refer to => [ Heat Output and Temperature Door Activation, Checking, Comfort ] Heat Output and Temperature Door Activation, Checking, Comfort.