Heater Core Preparing For Removal
Heater Core Preparing for Removal
Special tools, testers and auxiliary items required
• Hose Clamps up to 25 mm (3094) or Hose Clamps up to 40 mm (3093)
• Commercial compressed-air gun with rubber end piece
• Cooling System Tester (V.A.G 1274) (and corresponding adapter)
- Switch on the ignition.
- Set the air flow direction to "DEF" on the Climatronic control module (J255).
- Move the passenger seats as far back as possible.
- Turn off the ignition.
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.
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.
The following procedure requires working on the high voltage system. De-energize the high voltage system.
- De-energize the high voltage system.
Disable the high voltage system
Risk of electrocution
Death or serious bodily injury by electric shock.
• People with electric/medical life- and health sustaining devices in or on their person must not perform any work on the high voltage system for safety reasons. Internal pain killer pumps, implanted defibrillators, pacemakers, insulin pumps and hearing aids among others are considered life- and health sustaining devices.
• The high voltage system may only be activated by qualified personnel (Audi high voltage mechanic).
• Make sure that the high voltage system is completely disabled. Assure that the voltage performed exclusively using the Vehicle Diagnosis Tester according to the "Guided Fault Finding".
• The qualified personal (Audi high voltage technician) determines the voltage and secures the system from restarting using the locking cap (T40262). Keep the ignition key and the high voltage system maintenance connector (TW) safely with the qualified personal to secure the system from restarting.
• The qualified personal (Audi high voltage technicians) marks the vehicle by attaching warning labels.
• Disable the high voltage system:
• Connect the vehicle diagnosis tester
• Select the Guided Fault Finding mode
• Using the GO TO button, select the following menu commands
• Functions/Component selection
• Body
• Electrical Equipment
• OBD-capable system
• 8C - Hybrid battery management -J840
• 8C - Hybrid battery management, functions
• 51 - Disable the high voltage system.
- Disconnect the ground cable from the battery.
- Remove the rubber seal - A - and the plenum chamber cover - B - (there are different versions).
• Inspect the high voltage components - D - (the electric drive power and control electronics (JX1) ) and the high voltage cables - E - after removing the plenum chamber cover - B -. Refer to => [ Visual Inspection of High-Voltage Components and Cables for Damage ] Visual Inspection of High-Voltage Components and Cables For Damage.
- Remove the cowl panel - C -.
- Loosen the power distribution panel - 1 - and move it toward the windshield with the wires.
- Remove the high voltage cables leading to the electric A/C compressor (V470) and from the traction battery (A2) and electric drive power and control electronics (JX1).
- Cover the electric drive power and control electronics (JX1) and wires to prevent them getting damaged and to protect them from dirt.
• Use clean 20 mm bungs - B -, taken from engine bung set (VAS 6122) , to seal off the connection on the electric drive power and control electronics (JX1) - A -.
• Be careful not to damage any high voltage components - D - or the high voltage cables - E -.
• Inspect the high voltage components - D - and high voltage cables - E - after completing the work procedure and before installing the plenum chamber cover - B -.
For vehicles without a high voltage system
- Remove the plenum chamber cover (not always necessary, there are different versions).
- Disconnect the ground cable from the battery.
• Disconnect the battery ground connection so that it cannot short circuit when the jumper cable post - C - is removed.
- Remove the jumper cable post cover - C -.
- Remove the jumper cable post - C - from the strut dome and lay it to the side.
All vehicles
- Remove the air intake housing. Refer to => [ A/C Unit Air Intake Housing ] A/C Unit Air Intake Housing.
- Disconnect the connector from the Evaporator Vent Temperature Sensor (G263). Refer to => [ Evaporator Vent Temperature Sensor (G263) ] Evaporator Vent Temperature Sensor (G263).
• From 01.2008, A/C units which have an additional connection for the glove compartment cooling are being installed, refer to => [ Glove Compartment Cooling to Air Intake Manifold Connection ] Glove Compartment Cooling to Air Intake Manifold Connection. Make sure the correct right heater core housing and air intake hosing (different versions) are installed. Refer to Electronic Parts Catalog (ETKA).
• The activation of the temperature doors and with it the right heater core housing is different between vehicles equipped with "Comfort" and "Basis" A/C systems. Refer to => [ A/C Unit and Air Intake Housing Components ] A/C Unit and Air Intake Housing Components and to the Parts Catalog.
• To maintain the A/C stability, only one heater core housing (the left or right side) may be removed with the A/C installed.
• Depending on the production date, there are different versions of the levers and connections on the A/C unit. Refer to => [ Air Conditioner, Levers and Connecting Elements ] Air Conditioner, Levers and Connecting Elements and the Electronic Parts Catalog (ETKA).
• Vehicles with the "Comfort" A/C system can have the right heater core housing and the mounting plate installed/removed for the motors removed/installed. Vehicles with the "Basis" A/C system do not have this mounting plate.
Do not remove the left and right heater core housings at the same time.
• Both heater core housings support components of the air conditioner must not be removed at the same time. Otherwise the air conditioner will become unstable.
• If necessary, remove the left and right heater core housing one after the other.
• Right heater core housing, removing and installing (vehicles with "Basis" A/C system and vehicles with "Comfort" A/C system, where the right mounting plate and motors and the right heater core housing must be removed one after the other), refer to => [ Right Heater Core Housing, Motor Mounting Plate Removed ] Right Heater Core Housing, Motor Mounting Plate Removed.
• Right heater core housing together with the right mounting plate and motors, removing and installing (only on vehicles with "Comfort" A/C system), refer to => [ Right Heater Core Housing and Right Motor Mounting Plate ] Right Heater Core Housing and Right Motor Mounting Plate.
• Heater core, removing, refer to => [ Heater Core Removing and Installing ] Heater Core Removing and Installing.