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Mode of operation of air quality sensor G238 > < Electrical checking of solar roof

A4 Cabriolet Mk2

Checking operation of solar roof
Checking operation of solar roof
–  Move vehicle into the sun.
  Note
If weather conditions are not suitable, shine two commercially available 1000 W halogen lamps for example onto the solar roof, maintaining a distance of at least 500 mm from the solar roof. To enable the solar cells -C20- to supply sufficient electrical energy to drive the fresh air blower -V2-, it must be ensured that all sun roof solar cells -C20- are evenly and fully illuminated.
–  Open “centre” dash panel vents and close all other vents.
–  Switch off ignition (operating and display unit, Climatronic control unit -J255- blank).
–  Close sun roof.
A current of air can be felt from the dash panel vents (moisten palm of hand to check if necessary).
If no current of air can be felt:
–  Check encoding of operating and display unit, Climatronic control unit -J255- (for vehicle with solar roof) → Chapter
–  Remove glove box. → General body repairs, interior; Rep. Gr.68
   
–  Unplug connector -A- from fresh air blower control unit -J126-.
–  Measure voltage between contact -6- and contact -3- at connector -A-.
t  Specification: 8....12 V DC (depending on sunlight intensity)
–  Connect up test lamp (12 V, max. 5 W) between contacts -6- and -3- at connector -A-.
–  Test lamp glows or lights (depending on sunlight intensity).
  Note
t  If the test lamp glows or lights, the solar roof is functioning properly. If the fresh air blower -V2- does not run, check freedom of movement of fresh air blower -V2-. If no fault is found, replace fresh air blower control unit -J126- with fresh air blower -V2-.
t  If the test lamp does not glow or light, check the wiring to the two contacts at the sun roof opening. If no fault is found, check solar panel → Current flow diagrams, Electrical fault finding and Fitting locations and → General body repairs, exterior; Rep. Gr.60.
t  The electrical energy supplied is only approx. 1.5 W on shining halogen lamps onto the solar roof (fresh air blower -V2- rotates but air flow is hardly perceptible).
  A87-0388

Mode of operation of air quality sensor G238 > < Electrical checking of solar roof