Heating Output And Temperature Door Activation, Testing Requirements
On vehicles with a high voltage system (hybrid vehicles)
Observe all of the additional warnings for all work performed on vehicles with the high voltage system. Refer to HIGH VOLTAGE VEHICLES SAFETY PRECAUTIONS and HIGH VOLTAGE SYSTEM GENERAL WARNINGS for Hybrid .
If it is necessary for the following procedure to perform work near high voltage components, "perform a visual inspection of the high voltage components and cables for damages" (refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES ) and "always follow the warnings when working on the high voltage system". Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS for Hybrid .
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.
Handling high voltage cables:
- 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.
- The round high voltage connectors are color coded with an external color ring and are mechanically coded using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid any mechanical damage 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 Electrical 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 covers 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 for example Battery Charger VAS5903 to the battery jump start terminal for the 12V vehicle electrical system
- Switch on the ignition.
-- Charge the vehicle battery, for example, using the Battery Charger VAS5903 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures when the ready mode is active. Refer to Battery Charger VAS5095A SUPPORT MODE and HIGH VOLTAGE SYSTEM GENERAL WARNINGS for Hybrid .
-- 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 Owner's Manual.
Activate and deactivate the ready mode. Refer to Owner's Manual (consult the display in the Instrument Cluster Control Module -J285-).
All vehicles
From 01/2008, A/C units which have an additional connection for the glove compartment cooling are being installed as a running change. On vehicles without glove compartment cooling, this connection is sealed with a plug. Refer to GLOVE COMPARTMENT COOLING CONNECTION ON AIR INTAKE HOUSING . 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.
- The coolant circuit is bled according to specifications. Refer to COOLANT, DRAINING AND FILLING for 2.0L, COOLANT, DRAINING AND FILLING for 3.0L, or COOLANT, DRAINING AND FILLING for 3.2L
- 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 are OK and properly installed.
- Air flow through dust and pollen filter not obstructed by dirt. Refer to DUST AND POLLEN FILTER, REMOVING AND INSTALLING .
- The 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 CONNECTION ON AIR INTAKE HOUSING .
- The vehicle is not exposed to sunlight.
- The DTC memory of the Climatronic Control Module -J255- display and control head was checked and erased, the basic setting was performed and the Climatronic Control Module -J255- A/C display and control head coding was checked, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- The adaptation of the Climatronic Control Module -J255- A/C display and control head was checked, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
- All instrument panel vents are open.
- The hood is closed.
On vehicles with a high voltage system (hybrid vehicles)
- The ignition is turned on and the ready mode is active, the engine starts or only runs when warmer coolant is necessary to reach the temperature setting in the passenger compartment or, for example, the Traction Battery -A2- (hybrid battery) has not been charged enough.
- With the ignition turned on and at the temperature preset "warm" on the Climatronic Control Module -J255- A/C display and control head ("HI" in the display for the A/C display and control head and the MMI).
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 for example Battery Charger VAS5903 to the battery jump start terminal for the 12V vehicle electrical system
- Switch on the ignition.
For vehicles without a high voltage system
- The engine is running.
- With the engine running and at the temperature preset "warm" on the Climatronic Control Module -J255- A/C display and control head ("HI" in the display for the A/C display and control head and the MMI).
All vehicles
- With the engine running (ready mode is active for vehicles with a high voltage system) and at the temperature preset "warm" on the Climatronic Control Module -J255- A/C display and control head ("HI" in the display for the A/C display and 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 Shut-Off Valve -N82- /Climatronic Coolant Shut-Off Valve -N422- LOCATION, ACTIVATION AND FUNCTION .
-- On vehicles with a regulated coolant circuit (only installed on certain engines from MY 2011), the activation and function of these components is OK. Refer to COOLANT PUMP/THERMOSTAT for 2.0L, COOLANT PUMP/THERMOSTAT for 3.0L, or COOLANT PUMP/THERMOSTAT for 3.2L
On vehicles with an engine with a regulated coolant circuit (for example, with a regulated coolant pump and a Cylinder Head Coolant Valve -N489-), no Climatronic Coolant Shut-Off Valve -N422- /Coolant Shut-Off Valve -N82- is currently installed. On an engine with a regulated coolant pump, the engine control module activates the coolant pump, and in doing so regulates the coolant circuit. Refer to COOLANT PUMP/THERMOSTAT for 2.0L, COOLANT PUMP/THERMOSTAT for 3.0L, or COOLANT PUMP/THERMOSTAT for 3.2L .
-- This is actuated on vehicles with a Coolant Recirculation Pump -V50- (Water Pump -V36-) (not on all vehicles, installed, for example, on the 6-Cylinder FSI engines and on vehicles having the Start/Stop System without an "parking heater" and on high voltage vehicles). Refer to OVERVIEW - COMPONENTS OUTSIDE OF PASSENGER COMPARTMENT - Component Group "3" and Coolant Recirculation Pump -V50- (Water Pump -V36-), LOCATION, ACTIVATION AND FUNCTION, VEHICLES WITH 6-CYLINDER GASOLINE ENGINE .
The following is set on the Climatronic Control Module -J255- A/C display and control head "Basis" version:
- "Auto" operating mode (indicator lamp in the AUTO button lights up).
- Temperature preset "cold" ("LO" in the MMI display).
- A/C compressor is turned on (the indicator lamp in the AC or A/C button turns on).
- Preset for the fresh air blower "maximum speed" (in the Multi Media Interface display, setting "10" or greater).
The following is set on the Climatronic Control Module -J255- A/C display and control head "Convenience" version:
- "Auto" mode (the indicator lamp in both AUTO buttons illuminate).
- Temperature preset "cold" for the driver and front passenger side ("LO" for the driver and front passenger side in the display for the A/C display and control head and the MMI).
- A/C compressor is turned on (the indicator lamp in the AC or A/C button turns on).
- Preset for the fresh air blower "maximum speed" (display in the A/C display and control head and the MMI, setting "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 "Convenience" 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 "Convenience" 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 diesel engine or a gasoline engine with an auxiliary heater.
The type of auxiliary heating depends on the vehicle equipment level. At the start of production, all vehicles with a diesel engine have an Auxiliary Heater Heating Element -Z35- ; at a later point in time, on vehicles with the optional equipment "parking heater", the Auxiliary Heater Heating Element -Z35- will be discontinued and the parking heater will be actuated as the auxiliary heater.
Check the activation and function of the auxiliary heater on vehicles with an Auxiliary Heater Heating Element -Z35- if there is complaint about the heating output being insufficient when the outside air temperatures are low. Refer to Auxiliary Heater Heating Element -Z35-, CHECKING .
As a running change in MY 2010, gasoline engines that can run on bioethanol (Flex Fuel vehicles) were introduced, which currently have an Auxiliary Heater Heating Element -Z35-. Refer to Auxiliary Heater Heating Element -Z35-, CHECKING .
Currently an Auxiliary Heater Heating Element -Z35- is also installed on vehicles with a high voltage system (hybrid vehicles) and a gasoline engine. Refer to Auxiliary Heater Heating Element -Z35-, CHECKING .
Functions when the engine is running (non-hybrid vehicles)/activated ready mode (hybrid vehicles):
On vehicles with a high voltage system (hybrid vehicles) and on vehicles with the start stop system, the engine only runs when an additional heat output is needed to reach the set temperature.
-- The coolant fan(s) (Coolant Fan -V7- and Coolant Fan 2 -V177-) run (activation and speed depend on refrigerant circuit pressure and engine temperature).
Depending on the version of the Climatronic Control Module -J255- A/C display and control head, the coolant fan(s) (Coolant Fan -V7- and Coolant Fan 2 -V177-) are only switched on starting at a certain refrigerant circuit pressure (currently starting at a pressure of approximately 9 bar (131 psi)). The coolant fan(s) activation is displayed in the measured values block, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
-- 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 system 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 air recirculation door is opened. The Fresh Air Blower -V2- extracts the air from the passenger compartment below instrument panel/glove compartment.
If one of these requirements is not met, check the DTC memory, perform the output diagnostic test mode and read the measured values block, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
If the above mentioned requirements are fulfilled:
- Check the heating output and temperature door activation (on the A/C system "Basis" version). Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Basis" VERSION .
- Check the heating output and temperature door activation (on the A/C system "Convenience" version). Refer to HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Convenience" VERSION .