GM Service Manual Online
For 1990-2009 cars only
  1. Place a bubble level against the front of the radar. Adjust the vertical control until the radar is level.
  2. For horizontal adjustment, measure the back of the horizontal adjuster. Adjust the horizontal until 6 mm (0.25 in) of the adjuster is protruding out behind the radar. This method should work assuming that the bracket and frame have not been damaged in a collision.
  3. Use a scan tool to perform a Factory Reset of the adaptive cruise module (ACM). Ensure that the Auto Alignment Learn Status parameter indicates Not Aligned. This allows the forward looking sensor (FLS) to automatically align itself during vehicle driving.
  4. Drive the vehicle at speeds of at least 56 kph (35 mph), so that the automatic alignment process can operate. The process requires the radar to observe stationary targets along the edge of the road (i.e. mail boxes, parked cars, poles, signs, etc.). Do not follow other vehicles too closely, since this obscures the view for the radar.
  5. Use a scan tool to monitor the Auto Alignment Learn Status parameter. Continue driving until the Auto Alignment Learn Status parameter indicates Aligned. Typically, it will require less than 10 miles of driving. If not proceed to step #4. If the resulting Alignment Error is within -1.5 and 1.5 degrees, the alignment is within specification. Otherwise, proceed to step #6.
  6. Adjust the horizontal adjuster according to the Alignment Error chart provided below. Then, repeat steps 3, 4, and 5.

Adaptive Cruise Control Horizontal Adjustment Table

Tech 2 Alignment Error - Degrees

Number of Turns of Adjuster

RHT (Right-Hand Turn)

LHT (Left-Hand Turn)

Lower Limit

Upper Limit

-5.85

-5.549

9 ½

RHT

-5.55

-5.249

9

RHT

-5.25

-4.949

8 ½

RHT

-4.95

-4.649

8

RHT

-4.65

-4.349

7 ½

RHT

-4.35

-4.049

7

RHT

-4.05

-3.749

6 ½

RHT

-3.75

-3.449

6

RHT

-3.45

-3.149

5 ½

RHT

-3.15

-2.849

5

RHT

-2.85

-2.549

4 ½

RHT

-2.55

-2.249

4

RHT

-2.25

-1.949

3 ½

RHT

-1.95

-1.649

3

RHT

-1.65

-1.349

2 ½

RHT

-1.35

-1.049

2

RHT

-1.05

-0.749

1 ½

RHT

-0.75

-0.449

1

RHT

-0.45

-0.149

½

RHT

-0.15

0.149

0

--

0.15

0.449

½

LHT

0.45

0.749

1

LHT

0.75

1.049

1 ½

LHT

1.05

1.349

2

LHT

1.35

1.649

2 ½

LHT

1.65

1.949

3

LHT

1.95

2.249

3 ½

LHT

2.25

2.549

4

LHT

2.55

2.849

4 ½

LHT

2.85

3.149

5

LHT

3.15

3.449

5 ½

LHT

3.45

3.749

6

LHT

3.75

4.049

6 ½

LHT

4.05

4.349

7

LHT

4.35

4.649

7 ½

LHT

4.65

4.949

8

LHT

4.95

5.249

8 ½

LHT

5.25

5.549

9

LHT

5.55

5.849

9 ½

LHT