Audi Workshop Service and Repair Manuals

Removing heater   Note t  If necessary, obtain the radio anti-theft code before disconnecting the battery -A-. t  On vehicles with electrically adjustable seats, move the seats to the rearmost position before disconnecting the battery -A- → General body repairs, interior; Rep. gr.72. t  On removing bolts, note down bolt lengths and assignment for re-installation. t  All cable ties and other wiring harness fasteners detached or cut open on removing the heater must be re-attached in the same position on installation. t  Depending on the vehicle equipment and the engine, the coolant hoses may be provided with thermal insulation. This must not be damaged and must be re-attached following installation. –  Switch off ignition. –  Place protective covers over driver's and front passenger's seats. –  Disconnect the battery -A-. → Electrical system; Rep. gr.27 –  Dissipate the pressure in the coolant circuit by opening the cap at the coolant expansion tank. → Engine, mechanics; Rep. gr.19

–  Remove any components impeding access to the coolant hoses to the heat exchanger in the engine compartment -A- and -B- → Engine, mechanics; Rep. gr.13.   Note t  Depending on the engine and vehicle model, it may be necessary to unfasten or remove the following components: Top engine cover, compressed air pipe to throttle valve unit and intake manifold etc. → Engine, mechanics; Rep. gr.13.

t  There are different versions of the heat shield -B-. With version „1“, it is not necessary to remove the speed nuts -A- and to detach the heat shield -B- from the vehicle (the coolant hoses can be detached even with the heat shield fitted).

t  With version „2“, the clamping washers -A- and the clip -C- have to be removed and the heat shield -B- detached from the vehicle. t  For greater clarity, the illustrations show the heat shield -B- with the engine removed. –  If fitted and if applicable, detach the heat shield -B- from the bulkhead and lay it aside (or remove it completely).

–  If fitted, slide back the thermal insulation -D- and -E- so as to permit attachment for example of the hose clamps up to 40 mm -3093--F- to the coolant hoses -A- and -B-.

–  Mark the positions of the coolant hoses -A- and -B-.   Note t  The heat exchanger is designed for a certain coolant flow direction. Care must therefore be taken to connect the coolant hoses correctly (coolant hose -A-: supply from cylinder head, coolant hose -B-: return to coolant pump). t  The arrangement of the coolant hoses is identical for vehicles without air conditioner (heater only) and with air conditioner. This illustration shows the layout on a vehicle with air conditioner. t  Bleeding coolant circuit → Engine, mechanics; Rep. gr.13. –  If necessary, pinch off the breather hose (from the top connection -A- to the coolant expansion tank). –  Cover the area beneath the connections for the coolant hoses -A- and -B- with absorbent paper, for example. –  Pinch off the coolant hoses to the heating system heat exchanger (e.g. using hose clamps up to dia. 40 mm -3093-) and detach the hoses.

–  Attach a section of tubing -A- to the top connection. –  Hold a vessel -B- beneath the bottom connection -C-. –  Use a compressed-air gun to carefully blow the coolant out of the heat exchanger (into the vessel -B-). –  Remove the glove compartment, the driver's storage compartment, the centre console and the dash panel → General body repairs, interior; Rep. gr.70.   Note So as not to damage the dash panel fascia, the dash panel is only to be placed on a clean workbench covered, for example, with clean cardboard. –  Remove the accelerator pedal module → Fuel system; Rep. gr.20.

–  Remove the left and right vents -C-. –  Fold the driver and passenger side floor covering to the rear to permit removal of the footwell vents for the rear passenger compartment -A- and -B- → General body repairs, interior; Rep. gr.70. –  Remove both footwell vents for the rear passenger compartment -A- and -B-. –  Remove the fresh air blower -V2- → Chapter. –  Remove the heater controls (heater control unit -J65-) (leave the base plate of the heater controls in position) → Chapter. –  Remove the dash panel and dash panel cross member (central tube) → General body repairs, interior; Rep. gr.70.

–  Remove the data bus diagnostic interface -J533- (attached in the area of the steering column to the holder -A-) → Electrical system; Rep. gr.90. –  Remove the bolts -B- and detach the holder -A- from the heater (leave the holder attached to the wiring harness in the vehicle).

–  Remove both bolts -A- at the holder for the wiring harness -B-. –  Unplug the connector -C-. –  Release the vehicle wiring harness fasteners (e.g. cable ties) at the heater. –  On vehicles with electric supplementary heater (vehicles with diesel engine only), disconnect the power supply wiring from the supplementary air heater element -Z35- → Chapter. –  Unplug all connectors between the vehicle wiring harness and the electrical components of the heater.   Note The „heater“ wiring harness is removed together with the heater.

–  Carefully pull the right side of the heater slightly to the rear (such that the bolt -B- at the right holder -A- can be slackened off).   Note t  Only pull gently on the heater so as not to break the holder -A-. t  Slackening off the bolt -B- involves reaching between the heater and the floor covering at the right wheel housing (the fresh air blower must be removed beforehand). –  Remove the bolts -B- and detach the holder -A- from the heater (leave the holder attached to the wiring harness in the vehicle).

–  Unfasten the flange for the coolant pipes to the heat exchanger -A- from the lead-throughs of the grommet -B-.   Note t  On removing the heater, pay attention to both coolant pipes to the heat exchanger to ensure that they do not catch on the opening to the plenum chamber or on the noise insulation mat and become bent or damaged. t  Pay attention to the wiring harness. Pulling too firmly could damage individual wires.

–  Remove the heater -A- towards the passenger side (the layout and housing design are identical on vehicles without air conditioner, with heater only and with air conditioner).