GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Epica 🢒 Body Systems 🢒 Lighting 🢒 Headlight Leveling Inoperative

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The headlamp leveling switch can be removed for testing if the driver side instrument panel (I/P) cover is carefully pulled loose from its retaining clips. By reaching behind the loosened trim panel, the retaining tabs for the headlamp leveling and dimmer switch can be pressed to release the switch from the I/P.

Step

Action

Values

Yes

No

1

Check the high beam and the low beam headlamps.

Do the high beam and low beam headlamps work?

--

Go to Step 3

Go to Step 2

2

Repair the high beam and the low beam headlamps before completing this diagnostic table.

Does the leveling system operate after the headlamps have been repaired?

--

System OK

Go to Step 3

3
  1. Disconnect the connector at the inoperative headlamp leveling motor.
  2. Turn the low beam headlamps ON.
  3. Inspect the voltage at the YEL wire at the left headlamp leveling motor connector or the BRN/WHT wire at the right headlamp leveling motor connector.

Does the voltage measure within the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit between the low beam headlamp and the headlamp leveling motor.

Is the repair complete?

--

System OK

--

5

Use an ohmmeter to measure continuity between the BLK wire at the headlamp leveling motor connector and ground.

Does the ohmmeter indicate the specified value?

0 ohms

Go to Step 7

Go to Step 6

6

Repair the open circuit between the headlamp leveling motor connector and ground.

Is the repair complete?

--

System OK

--

7
  1. Turn the low beam headlamps ON.
  2. At the headlamp leveling motor connector, inspect the voltage while the leveling adjustment is changed from 0 to 3 on the leveling switch.

Does the voltage change smoothly and measure within the specified values?

11-14 at position 0 to 4.5 V at position 3

Go to Step 8

Go to Step 9

8

Replace the headlamp leveling motor.

Is the repair complete?

--

System OK

--

9

  1. Remove the headlamp leveling switch for testing, but do not disconnect the electrical connector.
  2. Turn the low beam headlamps ON.
  3. Measure the voltage at the BRN wire at the headlamp leveling switch.

Is the voltage within the specified range?

11-14 V

Go to Step 13

Go to Step 10

10
  1. Remove the headlamp switch for testing, but leave the electrical connectors connected.
  2. Turn the low beam headlamps ON.
  3. Measure the voltage at the BRN wire at the headlamp and turn signal switch seven pin connector.

Does the voltage measure within the specified range?

11-14 V

Go to Step 12

Go to Step 11

11

Replace the headlamp switch.

Is the repair complete?

--

System OK

--

12

Repair the open circuit in the BRN wire between the headlamp switch and the headlamp leveling switch.

Is the repair complete?

--

System OK

--

13
  1. Turn the low beam headlamps ON.
  2. With the headlamp leveling switch removed for testing and the electrical connector still connected, measure the voltage at the DK GRN wire at the headlamp leveling switch with the switch dial set at 0.

Does the voltage measure within the specifed range?

11-14 V

Go to Step 15

Go to Step 14

14

Replace the headlamp leveling switch.

Is the repair completed?

--

System OK

--

15
  1. Turn the low beam headlamps ON.
  2. With the headlamp leveling switch removed for testing and the electrical connector still connected, measure the voltage at the DK GRN wire at the headlamp leveling switch as the switch is dialed to 3.

Does the drop in voltage equal the specified value?

4.5 V

Go to Step 16

Go to Step 14

16

Repair the open DK GRN wire between the headlamp leveling switch and the headlamp leveling motors.

Is the repair complete?

--

System OK

--