GMC Yukon 2000–2006

Manufacturer communication2003–2006 GMC YUKON ・ 2019-06-10(1 earlier editions of this document folded here)

Daytime Running Lamps Will Not Shut Off in Canada-Built Vehicles

1. 1Fault

   • Lights (headlights, turn signals)
   • Some customers may state that the Daytime Running Lamps (DRLs) or the auto headlamps will not shut off when using the daytime running lamp disable switch, which is part of the headlamp switch.
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2. 2Finding the cause

   Possible causes

   • Vehicles built for Canada (RPO Z49) have different software that does not allow the DRLs or auto headlamps to be shut off.
   • Canadian law prohibits disabling daytime running lamps (DRLs) or auto headlamps.
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3. 3Correction

   Caution

   • This is a normal operation of the vehicle and no repairs should be attempted.

Manufacturer communication2000–2006 GMC YUKON DENALI ・ 2019-04-08(2 earlier editions of this document folded here)

Vehicle Lean Adjustment Preliminary Information

1. 1Fault

   • Lights (headlights, turn signals)
   • The procedure is for diagnosing and correcting complaints of the vehicle leaning left or right.
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2. 2Finding the cause

   Steps to confirm (in the document’s order)

   1. Measure fender wheel-opening heights, front and rear, to quantify vehicle lean.
   2. The front wheel-opening height is known as P height, and the rear wheel-opening height is known as R height.
   3. P height and R height are the distance from the ground to the highest point on the wheel-opening, going through the center of the wheel.
   4. Before measuring, make sure the vehicle is on a level surface, such as an alignment rack.
   5. Before measuring, check the fuel level and add weight if necessary to simulate a full tank.

   1 more points
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3. 3Correction

   Repair

   1. If Z height is out of spec and the D height delta is greater than 1/2 inch (12 mm), adjust Z height until it is within spec and the P and R height deltas are less than 1/2 inch (12 mm).
   2. If adjustment is not possible, check the front eye of the rear leaf spring for matching color-coded tape or paint; both sides should be the same color. If not, switch springs side to side; if so, replace the leaf spring on the lower side only.
   3. If this is not possible, shim the body and/or pick-up box until the P and R height deltas are less than 1/2 inch (12 mm).
   4. After all adjustments are done, perform a front-end alignment and check headlight aim.

Manufacturer communication2001–2006 GMC YUKON DENALI ・ 2024-01-19(2 earlier editions of this document folded here)

Headlamp, Tail Lamp, License Lamp or Fog/Driving Lamp Damage

1. 1Fault

   • Lights (headlights, turn signals)
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2. 2Finding the cause

   Possible causes

   • A variety of chemicals can cause crazing or cracking of the polycarbonate lens.
   • Bulbs with a higher output than original equipment run hotter, and the excess heat can melt the socket, housing or lens.

   Steps to confirm (in the document’s order)

   • Broken mounting tabs, rear housing fractures and loose components inside the lamp assembly are evidence of impact damage.
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3. 3Correction

   Repair

   • When servicing any exterior lighting assembly, transfer any electrical connection seals to the new part.

   Caution

   • Clean exterior lamps and lenses only with lukewarm or cold water, a soft cloth and a car washing soap.
   • Do not let a shop mat or fender cover drape over a headlamp while the DRL or headlamps are on; the lens may craze or deform.

Manufacturer communication2000–2006 GMC YUKON DENALI ・ 2023-02-28(5 earlier editions of this document folded here)

Exterior Lamp Condensation and Water Leaks Service Bulletin

1. 1Fault

   • Leak
   • Lights (headlights, turn signals)
   • Exterior lamps such as cornering, turn signal, backup, head or tail lamps may show very small water droplets, a fine mist or white fog (condensation) on the inside of the lens.
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2. 2Finding the cause

   Possible causes

   • Condensation occurs when the air inside the lamp assembly reaches the dew point through atmospheric changes.
   • Non-OE lamps are most often presented as holding moisture or with inoperative bulbs from corroded electrical connections; they appear to be installed as part of a collision repair.

   Steps to confirm (in the document’s order)

   1. Normal: the mist is located mainly in the lens corners near the vents and does not cover more than half the lens surface.
   2. Normal: the moisture clears when the vehicle is parked in a dry environment or driven with the lights on.
   3. Leak: water has accumulated in the bottom of the lamp assembly.
   4. Leak: the condition will not clear when the vehicle is parked in a dry environment or driven with the lights on.
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3. 3Correction

   Repair

   • A condition covering more than half the surface of the lamp lens indicates the need to service the lens or lamp assembly.

   Caution

   • Depending on the lamp and the atmospheric conditions, the time needed to clear the lamp may vary from 2 to 6 hours.
   • If the normal conditions are noted, advise the customer that replacing the lamp assembly may not correct the condition.
   • Moisture that "comes and goes" is considered a normal condition.

Manufacturer communication2003–2006 GMC YUKON DENALI ・ 2007-11-02

Turn Signal in Outside Rearview Mirror Does Not Illuminate

1. 1Fault

   • Lights (headlights, turn signals)
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2. 2Finding the cause

   Not stated

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3. 3Correction

   • Mirror Glass: replaced