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Checking, removing and installing fresh air intake > < Checking, removing and installing passenger compartment forced air extractor

A4 Mk3

Removing/installing, checking and cleaning plenum chamber water drain
Removing/installing, checking and cleaning plenum chamber water drain
Vehicles with a high-voltage system (hybrid vehicles)
For all work on vehicles with a high-voltage system, pay attention to the additional warnings for such vehicles → Chapter and → Electrical system; Rep. gr.93.
As work in the vicinity of high-voltage system components is necessary for the following sequence of operations, perform „Visual inspection of high-voltage components and cables for damage“ → Chapter and heed the „General warnings for working on high-voltage system“ → Electrical system; Rep. gr.93
  WARNING
Danger from unexpected engine starting
When performing general work on vehicles with a high-voltage system, switch off the ignition and remove the ignition key from the passenger compartment.
  WARNING
Working on vehicles with high-voltage wiring:
l  Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation.
l  High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation.
l  The round high-voltage connectors are colour-coded with an external coloured ring and are provided with mechanical coding or guide lugs. It is important to observe this coding when joining up the round high-voltage connectors, otherwise the connectors can be damaged.
  DANGER!
Risk of fatal injury if high-voltage components are damaged.
Observe the following when working in the vicinity of high-voltage components or wiring:
t  It is not permitted to use cutting or forming tools, other sharp-edged tools or heat sources such as welding, brazing, soldering, hot air or thermal bonding equipment.
t  Before starting work, visually inspect the high-voltage components in the areas involved.
t  Before working in the engine compartment, visually inspect the power electronics -JX1-, electric drive motor -V141-, air conditioner compressor -V470- and high-voltage wiring.
t  Before working on the vehicle underbody, visually inspect the high-voltage wiring and covers.
t  Before working on the rear section of the vehicle, visually inspect the high-voltage wiring and the electro-box with the maintenance connector for high-voltage system - TW -.
t  Visually inspect all potential equalisation lines.
Check the following when making the visual inspection:
t  There must be no external damage on any component.
t  The insulation of the high-voltage wiring and potential equalisation lines must not be damaged.
t  There must be no unusual deformation of the high-voltage wiring.
t  All high-voltage components must be identified by a red warning sticker.
–  Switch off the ignition.
   
–  Remove the rubber seal -A- and the plenum chamber cover -B- (different versions) → General body repairs, exterior; Rep. gr.50.
t  After removing the plenum chamber cover -B-, visually inspect the high-voltage components -D- (in this case the power and control electronics for electric drive -JX1-) and the high-voltage cables -E- → Chapter and → Electrical system; Rep. gr.93
t  When working in the area of high-voltage components -D- and high-voltage cables -E- always make sure that these components are not damaged → Electrical system; Rep. gr.93.
t  On completion of work and before fitting the plenum chamber cover -B-, visually inspect the high-voltage components -D- and the high-voltage cables -E- → Electrical system; Rep. gr.93.
  Note
If cleaning of the water drains involves removing the scuttle panel trim -C-, refer to → General body repairs, exterior; Rep. gr.50.
Vehicles with no high-voltage system
–  Switch off the ignition.
–  Remove the plenum chamber cover and / or scuttle panel trim (different versions) → General body repairs, exterior; Rep. gr.50.
All vehicles
  Note
t  The following illustration shows the positions of the components on an Audi A5 Coupé. The layout may differ slightly on the Audi A5 Sportback, Audi A4, Audi Q5 etc. Unless otherwise indicated, the components are however to be removed, installed and checked in the same manner as described for the Audi A5 Coupé.
  A87-11116
t  Drainage of water out of the plenum chamber may be impaired by deposits such as leaves and pine needles accumulating in the water drains -A-. The water level in the plenum chamber then rises if the vehicle is taken to an automatic car wash or in the event of heavy rain, water ingresses by way of the intake housing into the air conditioning unit and is blown by the fresh air blower -V2- onto the evaporator together with the air conveyed.
t  If the two sockets of the water drains -A- (on the right and left of the plenum chamber) are contaminated with leaves and pine needles, the drains may freeze up in winter and stop the water draining off. After a short journey, the heat emitted by the engine and exhaust system melts the ice in the drains again. By the time the vehicle arrives at the workshop, the water may have already drained out of the plenum chamber.
t  The sockets -A- of the water drains are clipped from above into the openings in the bottom of the plenum chamber.
t  In addition to the two sockets of the water drains -A-, there is also an opening -C- in the body on the right via which water can drain off into the area behind the wheel housing liners if the two sockets of the water drains -A- are sealed off. These openings are also to be checked for contamination.
Checking and cleaning
–  If necessary, remove the plenum chamber cover (different versions) → General body repairs, exterior; Rep. gr.50.
  Note
t  Use a commercially available illuminated endoscope for example for checking inaccessible water drains. A version with a water-proof flexible swan neck is practical.
t  For cleaning inaccessible water drains, use a commercially available flexible gripper tool for example to loosen and remove coarse dirt. Then rinse out the remaining dirt.
–  Clean the water drains on the left and right -A-.
–  Remove any deposits (leaves, pine needles) or other contamination from the plenum chamber.
–  Check for proper operation of the sockets -A- (the valves -B- must not be gummed up or sealed off by dirt)
Removing
–  Unfasten the sockets -B- from above from the openings for the water drains -A- in the bottom of the plenum chamber.
Installing
–  Clip the sockets -A- from above into the openings for the water drains in the bottom of the plenum chamber.
–  Following installation, check for proper operation of the sockets -A- (the valves -B- must not be gummed up and must close).
  A87-10421

Checking, removing and installing fresh air intake > < Checking, removing and installing passenger compartment forced air extractor