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Service Bulletin

File in Section: 08 - Body and Accessories

Bulletin No.: 01-08-42-001J

Date: April, 2014

INFORMATION

Subject: Exterior Lamp Condensation and Replacement Guidelines

Models: 2015 and Prior GM Passenger Cars and Trucks

This bulletin has been revised to update the model years to 2015, add information to theWater Leak section, add improved graphics and add information on Non-GM lamp

assemblies and GM Trademarks. Please discard Corporate Bulletin Number 01-08-42-001I.

The following information is being provided to betterdefine the causes of condensation in exterior lampsand includes guidelines for determining the differencebetween a lamp with a normal atmospheric condition(condensation) and a lamp with a water leak.Some exterior lamps, such as cornering, turn signal,backup, headlamps or tail lamps may exhibit very smalldroplets of water, a fine mist or white fog(condensation) on the inside of the lamp lens. This maybe more noticeable on lamps with “multi-lens” designsand may be normal during certain weather conditions.Condensation occurs when the air inside the lampassembly, through atmospheric changes, reaches the“dew point.” When this takes place, the moisture in theair within the lamp assembly condenses, creating a finemist or white fog on the inside surface of the lamp lens.Most exterior lamps on General Motors vehicles use avented design and feature a replaceable bulbassembly. They are designed to remove anyaccumulated moisture vapor by expelling it through avent system. The vent system operates at all times,however, it is most effective when the lamps are ONand when the vehicle is in motion. Depending on thesize, shape and location of the lamp on the vehicle, andthe atmospheric conditions occurring, the amount oftime required to clear the lamp may vary from2 to 6 hours. Customers with short commutes willexperience a longer time to clear the lamp.Completely sealed headlamp assemblies (sealedbeams) are still used on a limited number of modelsbeing manufactured today. These lamps require thereplacement of the complete lamp assembly if a bulbfilament burns out.

Condensation2014 Sierra Headlamp, Full and Partial Examples

3789054

Page 2 April, 2014 Bulletin No.: 01-08-42-001J

3789057

A Fine Mist or White Fog on the Inside Surface ofthe Lamp Lens Occurring After a Period of HighHumidity

• May be located primarily in the lens corners (nearthe vents) and SHOULD NOTcover more than halfthe lens surface.

• The condition should clear of moisture when thevehicle is parked in a dry environment, or whenthe vehicle is driven with the lights ON.

• A comparison of the equivalent lamp on theopposing side of the vehicle indicates a SIMILARperformance.

If the above conditions are noted, the customer shouldbe advised that replacement of a lamp assembly maynot correct this condition.

Water Leak2014 Acadia Tail Lamp Example

3803382

2014 Silverado Tail Lamp Example

3789062

2014 Camaro Headlamp Example

3789063

Numerous & Various Size Drops of Water Collectingon the Inside Surface of the Lamp Lens After theVehicle Has Been Exposed to Rain or a CarWashing Environment

Important: Moisture is most noticeable during theSpring and Fall of year, due to high humidity and thelarge fluctuation in temperature between day and night.Note: Any of the conditions listed below wouldindicate the need to service the lens or lamp assembly.

• A condition that covers more than half the surfaceof the lamp lens.

• An accumulation of water in the bottom of thelamp assembly.

Bulletin No.: 01-08-42-001J April, 2014 Page 3

• A condition that WON'T clear when the vehicle isparked in a dry environment, or when the vehicleis driven with the lights ON.

• A comparison of the equivalent lamp on theopposing side of the vehicle indicates a differentperformance.

Note: A different performance of lamps on oppositesides of a vehicle DOES NOTalways indicate that onelamp is bad, and the other is normal. For example, on acold day when the sun is hitting only one side of thevehicle, the normal condition of one side showing clearand the other showing fogging/moisture, could bemisinterpreted as a bad lamp. The customer maycomment that, or you may need to inquire if, themoisture “comes and goes.” Moisture “coming andgoing” is considered a normal condition.

If a lamp is found to be exhibiting a leak, review themost recent version of Service Bulletin02-08-42-001 for information regarding impactdamage inspection.

Non-GM Headlamp, Tail Lamp and Fog LampAssemblies

Many companies outside of General Motors aremanufacturing lamp assemblies that look very similar tooriginal equipment. They target high volume programslike, but not limited to, Impala, Malibu, and Full SizeTruck. These lamps are most often presented bycustomers as holding moisture or for inoperative bulbsdue to corroded electrical connections. It appears thesenon OE lamps get installed on vehicles as part of acollision repair. Most likely the customer has no ideathey are not original equipment, as the initialappearance is generally good. Obviously, these partsare not covered by warranty. Some of the commoncompany names seen on these lamps are Eagle Eyesand Depo.

2650251

This fog lamp was returned for retaining moisture. Asyou can see it is marked with the Depo brand (it is alsocalled out on the front lens).The most reliable way to identify a non OE part is tocompare it to the replacement service part or a likevehicle. Many do have the application called out on thepart with the letters GM being present. Notice that theyalmost never underscore it, as that would be atrademark violation. They often use substandard wiring,sockets, vent patches and unsealed connectors.

Examples of GM TrademarksNote: The graphics below are examples of GMTrademarks that may appear on lamp assemblies.Not all lamp assemblies currently have thetrademark, however future assemblies will containthe trademark on a label affixed to the assembly.

Page 4 April, 2014 Bulletin No.: 01-08-42-001J

2014 Cadillac XTS

3803767

2014 Chevrolet Silverado

3803768

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform thesetechnicians of conditions that may occur on some vehicles, or to provide information that could assist in the properservice of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do ajob properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that yourvehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from theinformation.

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