Auxiliary Air Heater Heating Element (Z35)/Honey Comb
Auxiliary Air Heater Heating Element (Z35)/Honey Comb
• Currently, vehicles with certain gasoline engines (for example, vehicles that can use bioethanol "Flex Fuel Vehicle" from MY 10 and on high voltage vehicles) have an electric auxiliary heater. Refer to the Audi Sales Program. The air is supplied with heat energy after leaving the heater core if there is a request from the Climatronic Control Module (J255) A/C control head.
• The respective engine control module activates the auxiliary heater heating element) (the control modules exchange information about this via the data bus system). Refer to the Vehicle Diagnostic Tester in "Guided Fault Finding".
• The activation of the auxiliary heater heating element occurs for vehicles with a gasoline engine from the Climatronic control module control head via the local Data bus (controlled using the same outlet and also using the fresh air blower control module (J126) ) on the auxiliary air heater control module (J604). The auxiliary air heater control module activates the low heat output relay (J359) and the high heat output relay (J360) (and these send the electricity to the auxiliary heater heating element). Refer to the Vehicle diagnostic tester in "Guided Fault Finding".
• Make sure the auxiliary air heater heating element is working. Refer to => [ Auxiliary Heater Heating Element (Z35), Testing ] Auxiliary Heater Heating Element (Z35), Testing.
• Vehicles without an auxiliary air heater heating element have a honey comb inside the air conditioner as a place holder. Refer to => [ Air Routing in Air Intake Housing and A/C Unit ] Air Routing In Air Intake Housing and A/C Unit and the Parts Catalog.
• In MY 2009, as a running change, a new version of the auxiliary air heater heating element is being installed (the heating element is a bit more narrow); be sure to use the correct version and note the allocation. Refer to Electronic Parts Catalog (ETKA).
Removing
- Switch on the ignition.
- Set the air flow direction to "DEF" on the Climatronic control module.
- Move the passenger seats as far back as possible.
- Turn off the ignition.
- 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).
- Carefully fold back the carpet around the center console and loosen the ground connection to the auxiliary air heater heating element - A - from the ground point on the right side of the center tunnel.
When folding back the carpet, be careful not to damage the center console.
- Disconnect the connector - B - and loosen the connector - C - from the right heater core housing.
- Loosen the wiring for the auxiliary air heater heating element - D - from the mounts on the heater core housing.
- Remove the right heater core housing. Refer to=> [ Right Heater Core Housing, Motor Mounting Plate Removed ] Right Heater Core Housing, Motor Mounting Plate Removed or => [ Right Heater Core Housing and Right Motor Mounting Plate ] Right Heater Core Housing and Right Motor Mounting Plate.
- Remove the auxiliary air heater heating element - A - from the A/C unit.
Installing
Installation is carried out in the reverse order while noting the following:
- The installed auxiliary air heater heating element (the honeycomb) has, depending the version of the A/C, is supplied with foam seals - A - and - B -.
1 Honeycomb for a vehicle equipped with a "Basis" A/C system.
2 Honeycomb for a vehicle equipped with a "Comfort" A/C system.
3 Auxiliary air heater heating element for a vehicle equipped with a "Basis" A/C system.
4 Auxiliary air heater heating element for a vehicle equipped with a "Comfort" A/C system.
• On vehicles with the "Comfort" A/C system, there are different temperature settings for the left and right sides as well as for the rear. The seal - B - separates the air guides for the left and right sides. Refer to => [ Air Routing in Air Intake Housing and A/C Unit ] Air Routing In Air Intake Housing and A/C Unit.
• The seal - B - must be applied in the center of the honey comb on the auxiliary air heater heating element.
• Seal may curl up on insertion if not correctly bonded on.
• If the seal is damaged or installed incorrectly, cold air can flow over the auxiliary air heater heating element (on the honeycomb); on vehicles equipped with the "Comfort" A/C system, it is possible that there is no clear separation between the left and right side.
- With the auxiliary air heater heating element removed, check the A/C, the heater corer and the evaporator - B - (honeycomb) for dirt; if necessary clean.
- Install the auxiliary air heater heating element (honeycomb) - A - in the A/C unit.
• On the "Comfort" A/C system, be careful when installing the groove - / spring connection - C - and - D -.
- Install the removed parts in the opposite order.
- Perform a basic setting and the output Diagnostic Test Mode (DTM) on the A/C system using the Vehicle diagnostic tester in "Guided Fault Finding".
• On this vehicle, the control motors are equipped with electronics. During the first basic setting, a new control motor learns its position on the air conditioner and can then be controlled by the A/C Control Head Climatronic Control Module (J255) (currently all control motors are identical). Check using the Vehicle diagnostic tester in "Guided Fault Finding".
• During the basic setting, the control motors are assigned and adapted corresponding to the switching sequence of the wiring. If this sequence does not conform with the specification, the control motors will adapt incorrectly and the door control will be wrong. Refer to => [ A/C Control Motor Block Diagram ] A/C Control Motor Block Diagram.
- Switch on the ignition.
- Check the Climatronic Control Module DTC memory and erase any displayed malfunction if necessary using the Vehicle diagnostic tester in "Guided Fault Finding".
- If necessary, check the auxiliary air heater heating element activation and function after installing. Refer to => [ Auxiliary Heater Heating Element (Z35), Testing ] Auxiliary Heater Heating Element (Z35), Testing.
- Adjust and check the air flow direction on the different air ducts via Climatronic control module, if the quantity of air actually changes at each setting.