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Mike, ASE Certified Technician
Category: Chevy
Satisfied Customers: 181
Experience:  Seventeen years of automotive experience with the past thirteen in General Motors dealerships.
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how do i adjust my headlights on my 2004 gmc envoy

Customer Question

how do i adjust my headlights on my 2004 gmc envoy
Submitted: 8 years ago.
Category: Chevy
Expert:  Mike replied 8 years ago.
HelloCustomer my name is Mike.


Below is the aiming proceedure for an Envoy. Please ask if you have further questions.


Headlamp Aiming

Screen Method for Headlamp Aiming


The screen method requires an area set up specifically for headlamp aiming.

The area should consist of a level surface large enough to allow for a vehicle and an additional 7.62 m (25 ft) as measured from the face of the headlamps to the aiming screen.

Object Number: 771622  Size: SH

The screen should be a wall or other flat surface at least 1.52 m (5 ft) high by 3.66 m (12 ft) wide with a matte white surface well shaded from extraneous light, and 90 degrees to the floor. The screen should be provided with a permanent vertical reference line 0.61 m (2 ft) from the left edge of the screen, 2 laterally adjustable vertical tapes, and one vertically adjustable horizontal tape.

After the aiming screen has been set up and located, paint or tape a reference line on the floor 15.24 m (50 ft) from the vertical reference line on the screen. This line should be perpendicular to the aiming screen and a mark placed at 7.62 m (25 ft) from the screen.

Headlamp Aiming Procedure


  1. Align the left tires of the vehicle with the reference line extending from the screen with the headlamps aligned with the reference line.
  2. Remove any snow, ice or mud from the vehicle.
  3. The vehicle must be fully assembled and all other work stopped while the headlamp aiming is being done.
  4. The vehicle must contain one person or approximately 160 lb (73 kg).
  5. Tires should be properly inflated.
  6. Rock the vehicle to stabilize the suspension.
    Object Number: 791936  Size: SH

  7. Measure from the floor to the reference mark on the headlamp lens (2).

    The graphic shows a GMC headlamp. Chevrolet is similar.

  8. At the screen, measure from the floor and place the horizontal tape at the above measured distance.
  9. Turn the low beam headlamps ON.
  10. The graphic shows the vertical (1) adjustment, no horizontal adjustments are required.

    The graphic shows a GMC headlamp, Chevrolet is similar.

    Adjust the headlamps to the specifications required by state and local authorities.

    Object Number: 792177  Size: SH
  11. The beam pattern must be positioned as shown in the graphic.

    Important: Do not place a cover directly on the headlamp assembly while the headlamp is ON.

  12. Adjust one headlamp at a time while blocking the light from the other. The cover must be away from the headlamp.

    The following list refers to the callouts in the graphic:

    The low beam centerline reference mark (4).
    Distance from ground to the low beam bulb centerline reference mark (1).
    The ground line (2).
    Horizontal edge of the low beam headlamp pattern (3).
    The edge of the headlamp pattern (3), must be 5 cm (2 in) below the reference mark (4), with the vehicle 7.62 m (25 ft) away.