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

Step

Action

Values

Yes

No

1

Inspect the headlamps.

Do the headlamps work?

--

Go to Step 3

Go to Step 2

2

Repair the headlamp system before completing this diagnostic table.

Has the headlamp system been repaired?

--

Go to Step 3

--

3

Inspect fuses EF18 and EF19.

Is either of the fuses blown?

--

Go to Step 5

Go to Step 4

4
  1. Inspect for a short circuit and repair if necessary.
  2. Replace the blown fuse.

Is the repair complete?

--

System OK

--

5
  1. Turn ON the headlamps.
  2. Inspect the voltage at fuses EF18 and EF19.

Is the voltage within the value specified at the fuses?

11-14 V

Go to Step 7

Go to Step 6

6

Repair the open circuit between the headlamp switch and fuses EF18 and EF19.

Is the repair complete?

--

System OK

--

7
  1. Disconnect the electrical connectors at the headlamp leveling motors.
  2. Turn ON the headlamps.
  3. Inspect the voltage at terminal C of the headlamp leveling motors.

Is the voltage within the value specified at both headlamp leveling motors?

11-14 V

Go to Step 9

Go to Step 8

8

Repair the open circuit between fuses EF18 and EF19 and the headlamp leveling motors.

Is the repair complete?

--

System OK

--

9

With the headlamp leveling motors disconnected, measure the resistance between ground and terminal A of the headlamp leveling motor connector.

Is the resistance equal to the specified value?

0 ohms

Go to Step 11

Go to Step 10

10

Repair the ground circuit for the headlamp leveling motors.

Is the repair complete?

--

System OK

--

11
  1. Turn ON the headlamps.
  2. With the headlamp leveling motors disconnected, inspect the voltage at terminal B of the headlamp leveling motor connector.

Is the voltage within the specified value?

6.2-10.6 V

Go to Step 17

Go to Step 12

12
  1. Disconnect the headlamp leveling and dimmer control switch.
  2. Turn ON the headlamps.
  3. Inspect the voltage at the PU wire at the headlamp leveling switch connector.

Is the voltage within the specified value?

11-14 V

Go to Step 14

Go to Step 13

13

Repair the open circuit between the headlamp relay and the headlamp leveling and dimmer switch.

Is the repair complete?

--

System OK

--

14
  1. Remove the headlamp leveling and dimmer switch.
  2. Use an ohmmeter to measure the resistance between the two terminals on the lower row of terminals. The are three terminals on the lower row, but only two of them connect to wires at the connector. Connect the ohmmeter to the switch terminals corresponding to the BK and D-BU/YE connector wires.

As the headlamp leveling thumbwheel is changed from position 0 to position 3, does the resistance change smoothly within the specified value?

440-850 ohms

Go to Step 16

Go to Step 15

15

Replace the headlamp leveling and dimmer switch.

Is the repair complete?

--

System OK

--

16

Repair the open circuit between the headlamp leveling and dimmer switch and the headlamp levelling motors.

Is the repair complete?

--

System OK

--

17
  1. Turn ON the headlamps.
  2. With the headlamp leveling motor disconnected, measure the voltage at terminal B of the headlamp leveling motor connector while turning the thumbwheel of the headlamp leveling switch.

Is the voltage smoothly change and match the values specified?

10.5 V at position 0 to 6.5 V at position 3

Go to Step 19

Go to Step 18

18

Replace the headlamp leveling switch.

Is the repair complete?

--

System OK

--

19

Replace the headlamp leveling motor.

Is the repair complete?

--

System OK

--