Rear lamps fogged up/not leaktight

Bulletin number

LI82.10-P-078069

Component

Exterior lighting

Summary

Complaint Rear lamps fogged up/not leaktight. Cause Fogging of the rear lamps is a natural phenomenon, which can occur under certain climatic conditions. This does not lead to any technical impairment of the rear lamps. Remedy Rear lamp: Remedy 1: Clearing fogged/condensed rear lamps: 1. Drive the vehicle into the workshop (temperature higher than +18 °C/+64.4 °F) Note: Do not wash the vehicle or subject it to high-pressure cleaning before the defogging test. 2. Switch off the engine and connect battery support via a charger. 3. Open the trunk. 4. Switch on the exterior lighting. 5. Leave the vehicle in this state for 60 minutes. 6. Check for formation of condensation -> a significant reduction in the formation of condensation must be clearly recognizable (defogging progress). Note: -If no reduction in the degree of fogging is visible, the rear lamp is defective and must be replaced. -It is not physically possible to defog the headlamps completely – some residual fogging may remain. Fogging does not impair the functionality or the service life of the rear lamps. -Simultaneous fogging of multiple component parts indicates extreme climatic conditions and also does not impair the functionality or the service life of the rear lamps. Remedy 2: You can recognize a defective rear lamp as follows: 1. Check the rear lamps to ensure that no external damage is present, and that the differential aeration cells and the diaphragm are present and correctly seated. -> If there are signs of external damage on the rear lamp, the component parts must be replaced as per WIS instructions. 2. Check the electrical connectors of the plugs and pins. -> If moisture/corrosion/etc. is present, the component part must be replaced as per WIS instructions. 3. Check for leak tightness -> Close all openings with Terostat IX or similar and establish and stabilize via an overpressure (40–50 mbar) via the plug. -> In the event of a sudden pressure drop, the component part must be replaced as per WIS instructions. Note: External damage to the rear lamps does not constitute a warranty or goodwill case.

Owners of these vehicles have filed 421 complaints in the lights category.