Manufacturer communication — 2006 GMC YUKON DENALI XL

• 2017 and prior GM passenger cars and trucks.

  the passage

  2017 and Prior GM Passenger Cars and Trucks

• The bulletin helps identify lamp conditions that are not considered warrantable.

  the passage

  This bulletin is being published to assist with the identification of issues that are not considered warrantable.

Possible causes

• A variety of chemicals can cause crazing or cracking of the polycarbonate lens.

  the passage

  A variety of chemicals can cause crazing or cracking of the polycarbonate lens.

• Rubbing compound, grease/tar/oil removers, tire cleaners, prep solvents for pin striping, cleaner/waxes, undiluted washer solvent, alcohol and even car wash soap in too high a concentration may damage the lens.

  the passage

  Also rubbing compound, grease/tar/oil removers, tire cleaners, prep solvents for pin stripping, cleaner/waxes, undiluted washer solvent, alcohol and even car wash soaps in too high a concentration may also damage the lens.

• Non-OE lamp assemblies most often come in for holding moisture or for inoperative bulbs due to corroded electrical connections.

  the passage

  These lamps are most often presented by customers as holding moisture or for inoperative bulbs due to corroded electrical connections.

• Bulbs with higher output than original run hotter, and the excessive heat can melt the socket, housing or lens.

  the passage

  Because the bulb output is higher, the operating temperature is also higher. This excessive heat can melt the socket, housing, or lens.

Steps to confirm (in the document’s order)

1. Broken mounting tabs, rear housing fractures and loose components inside the lamp assembly are evidence of impact damage.

   the passage

   Broken mounting tabs, rear housing fractures, and loose components inside the lamp assembly are evidence if impact damage.

2. The most reliable way to identify a non-OE part is to compare it with the replacement service part or a like vehicle.

   the passage

   The most reliable way to identify a non OE part is to compare it to the replacement service part or a like vehicle.

3. If in doubt, the bulb number should match the GM service part.

   the passage

   If in doubt, the bulb number should match the GM service part.

Repair

• When servicing any exterior lighting assembly, transfer any electrical connection seals to the new part; without them the connection may corrode from water entry.

  the passage

  When servicing any exterior lighting assembly, be sure to transfer any electrical connection seals to the new part. They are often on the body side of the harness connection, but may have stayed on the part being replaced. If not transferred to the new part, the connection may corrode due to water entry.

Caution

• Clean exterior lamps and lenses only with lukewarm or cold water, a soft cloth and a car washing soap.

  the passage

  Use only lukewarm or cold water, a soft cloth and a car washing soap to clean exterior lamps and lenses.

• Crazing or deformation of the lens may occur if a shop mat or fender cover covers part or all of the headlamp while the DRL or headlamps are on.

  the passage

  Crazing or deformations of the lens may occur if a shop mat or fender cover is draped over the fender and covers a portion or all of the headlamp assembly while the DRL or headlamps are on.