TSB-22-54-005

SUBJECT:
FOG OR DEW CONDENSATION IN
EXTERIOR LIGHTS (HEADLIGHTS/TAILLIGHTS)
No:
TSB-22-54-005
November 2022
DATE:
MODEL:
All Models
CIRCULATE TO:
[ ] GENERAL MANAGER
[ X ] PARTS MANAGER
[ X ] TECHNICIAN
[ X ] SERVICE ADVISOR
[ X ] SERVICE MANAGER
[ ] WARRANTY PROCESSOR
[ X ] SALES MANAGER
This TSB replaces both TSB-15-54-05 Dew Condensation in Headlights and Taillights &
TSB-22-54-003 Dew Condensation in Headlights and Taillights.
PURPOSE
Some customers may report condensation or fogging inside of the exterior lights (headlights or
taillights). This phenomenon occurs when the temperatures fluctuate between outside and
inside of the lights when vehicles are washed or driven in the rain/cold weather. The
condensation normally dissipates after drying in ambient temperatures and low humidity for
approximately an hour (i.e. well-ventilated or shaded location).
AFFECTED VEHICLES
All Models
PROCEDURE
Should a customer complain about fog or dew condensation, please refer to the following pages
(Supplemental Material) and explain that the condensation is not a failure of the exterior lights
but rather a natural phenomenon.
However, if an accumulation of water is found in the light or if condensation does not disappear
after drying in conditions mentioned above, inspect for possible damage such as a cracked lens,
poor sealing between the lens and housing, or a poorly fitted bulb socket.
Copyright 2022, Mitsubishi Motors North America, Inc.
The information contained in this bulletin is subject to change. For the latest version of this document, go to the
Mitsubishi Dealer Link, MEDIC, or the Mitsubishi Service Information website (www.mitsubishitechinfo.com).
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SUPPLEMENTAL MATERIAL
PURPOSE
There are two causes:
• Dew condensation
• Droplets on lens from water intrusion
Dew condensation is a natural phenomenon, not a failure. Therefore, part replacement will
not solve the issue.
The following material explains the phenomenon and may assist with inspection, prevent
unnecessary replacement and may be useful when explaining to the customer.
CONDENSATION CAUSE
Like the similar natural phenomenon of a foggy windshield in rainy/cold weather, the
following conditions may cause temporary condensation:
• If a lens gets cold quickly (due to cold air, rain, or car wash) the moisture holding
capacity of air decreases around the inside surface of the lens. In this situation, the
excess water in the air forms droplets, causing condensation (Cross-section view 1).
• After the temperature rises in a head or taillight (due to engine heat, sun, light, etc), the
moisture on the plastic inside the lights cools down around the surface of the lens and
becomes tiny water droplets causing condensation (Cross-section view 2).
The condensation typically evaporates by ventilation through the breathing vent after
vehicles are left for approximately an hour.
WATER INTRUSION CAUSE
When water accumulates in the light or when condensation does not evaporate by drying in a
place of ambient temperatures and low humidity (i.e., a well ventilated and shaded location),
inspect the component for possible defects.
Water may enter the light if the component is damaged with a cracked lens, poor seal
between the lens and housing, or from a poorly fitting bulb socket (Cross-section view 3).
These conditions cause larger droplets of water on the inside surface of the lens (Photos 1 &
2).
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WATER ACCUMULATION CAUSE (Continued)
WARRANTY INFORMATION
This bulletin is supplied as technical information only and is not an authorization to repair.
If an affected vehicle is reported with the described condition, diagnose the condition,
repair if necessary.
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