GM Service Manual Online
For 1990-2009 cars only

Headlamps Inoperative - High Beams Standard

Step

Action

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference: Lighting Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Are both high beam headlamps inoperative?

Go to Step 3

Go to Step 8

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Turn ON the high beam headlamps.
  4. With the scan tool, observe the High Beam Select Switch parameter in the instrument panel module (IPM) Inputs data list.

Does the data parameter display ACTIVE?

Go to Step 5

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the turn signal/multifunction switch C4 harness connector.
  3. Connect a 3-amp fused jumper between the headlamp high beam switch signal circuit and the ground circuit at the turn signal/multifunction switch C4 harness connector.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the High Beam Select Switch parameter in the IPM inputs data list.

Does the High Beam Select Switch parameter display ACTIVE?

Go to Step 13

Go to Step 11

5

  1. Turn OFF the ignition.
  2. Disconnect the headlamp HIGH BEAM relay located in the underhood fuse block. Refer to Relay Replacement .
  3. Connect a test lamp between the headlamp high beam relay control side supply voltage circuit and the headlamp high beam relay control circuit.
  4. Turn ON the ignition, with the engine OFF.
  5. Turn ON the high beam headlamps.

Does the test lamp illuminate?

Go to Step 6

Go to Step 10

6

Connect a test lamp between the headlamp high beam relay switch side supply voltage circuit and a ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 18

7

  1. Turn OFF the ignition.
  2. Connect a 40-amp fused jumper between the headlamp high beam relay switch side supply voltage circuit and the headlamp high beam supply voltage circuit.
  3. Turn ON the ignition, with the engine OFF.

Do both of the high beam headlamps illuminate?

Go to Step 14

Go to Step 8

8

  1. Disconnect the inoperative high beam headlamp bulb.
  2. Connect a test lamp between the high beam headlamp supply voltage circuit at the inoperative high beam headlamp bulb and the ground circuit of the inoperative high beam headlamp bulb.

Does the test lamp illuminate?

Go to Step 16

Go to Step 9

9

Test the headlamp high beam supply voltage circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 17

10

Test the headlamp high beam relay control circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 15

11

Test the turn signal/multifunction switch ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 12

12

Test the headlamp high beam switch signal circuit for an open, high resistance, or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 15

13

Inspect for poor connections at the C4 harness connector of the turn signal/multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 19

14

Inspect for poor connections at the headlamp high beam relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 20

15

Inspect for poor connections at the harness connector of the IPM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 21

16

Inspect for poor connections at the harness connector of the inoperative high beam headlamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 23

Go to Step 22

17

Locate and repair an open or high resistance in the headlamp ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 23

--

18

Locate and repair an open or high resistance in the switch side supply voltage circuit of the headlamp high beam relay. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 23

--

19

Replace the turn signal/multifunction switch. Refer to Turn Signal Multifunction Switch Replacement .

Did you complete the replacement?

Go to Step 23

--

20

Replace the headlamp high beam relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 23

--

21

Replace the IPM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 23

--

22

Replace the inoperative high beam headlamp bulb. Refer to Headlamp Bulb Replacement .

Did you complete the replacement?

Go to Step 23

--

23

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Headlamps Inoperative - High Beams with Intellibeam

Step

Action

Value

Yes

No

Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics and Inside Rearview Mirror Schematics

Connector End View Reference: Lighting Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

 

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Does the intellibeam indicator located on the inside rearview mirror (ISRVM) flash more than 3 times?

 

Go to Step 18

Go to Step 3

3

Perform the Intellibeam Demonstration Mode. Refer to Exterior Lighting Systems Description and Operation .

Does the intellibeam demonstration mode operate as described?

 

Go to Step 7

Go to Step 4

4

Did the high beam headlamps fade from full intensity to low intensity 3 times during the demonstration mode?

 

Go to Step 5

Go to Step 12

5

Did the intellibeam light sensor operate as described during the demonstration mode?

 

Go to Step 6

Go to Step 18

6

Did the intellibeam AUTO switch operate as described during the demonstration mode?

 

Go to Step 7

Go to Step 18

7

  1. Turn OFF the ignition.
  2. Disconnect the ISRVM harness connector. Refer to Inside Rearview Mirror Replacement .
  3. Connect a test lamp between the headlamp high beam relay control circuit and battery voltage.
  4. Turn ON the ignition, with the engine OFF.
  5. Place the headlamps switch in the AUTO position.
  6. Place the headlamp dimmer switch in the high beam position.

Does the test lamp illuminate?

 

Go to Step 9

Go to Step 8

8

Locate and repair an open or short to battery voltage in the headlamp high beam relay control circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Headlamps Inoperative - High Beams

9

  1. Turn OFF the ignition.
  2. Cover the sunload sensor located in the middle of the upper dash with a dark cloth.
  3. Connect a test lamp between the headlamp automatic high beam DIM enable circuit at the ISRVM harness connector and battery voltage.
  4. Turn ON the ignition, with the engine OFF.
  5. Place the headlamp switch in the AUTO position.

Does the test lamp illuminate?

 

Go to Step 11

Go to Step 10

10

Locate and repair an open or short the battery voltage in the headlamp automatic high beam DIM enable circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 20

11

Test the vehicle speed signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 18

12

  1. Turn OFF the ignition.
  2. Disconnect the automatic headlamp dimming relay. Refer to Inside Rearview Mirror Replacement .
  3. Connect a 15-amp fused jumper between the automatic headlamp dimming relay voltage supply circuit and the headlamp high beam voltage supply circuit.

Do the high beam headlamps illuminate?

 

Go to Step 13

Go to Step 16

13

Test the automatic headlamp dimming relay ground circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 14

14

Test the automatic high beam PWM signal circuit for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 15

15

  1. Turn OFF the ignition.
  2. Install the automatic headlamp dimming relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Place the headlamp switch in the AUTO position.
  5. Place the headlamp dimmer switch is in the high beam position.
  6. With a DMM, measure the voltage of the automatic high beam PWM signal circuit at the automatic headlamp dimming relay terminals.

Does the voltage measure less than the specified value?

2 V

Go to Step 19

Go to Step 18

16

Locate and repair an open, high resistance, or short to ground in the headlamp high beam voltage supply circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 17

17

Locate and repair an open or high resistance in the headlamp ground circuit. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 21

18

Inspect for poor connections at the harness connector of the ISRVM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 22

19

Inspect for poor connections at the harness connector of the automatic headlamp dimming relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 23

20

Inspect for poor connections at the harness connector of the instrument panel module (IPM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 24

21

Inspect for poor connections at the harness connector of the inoperative high beam headlamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

 

Go to Step 26

Go to Step 25

22

Replace the ISRVM. Refer to Control Module References for replacement, setup and programming.

Did you complete the replacement?

 

Go to Step 26

--

23

Replace the automatic headlamp dimming relay. Refer to Relay Replacement .

Did you complete the replacement?

 

Go to Step 26

--

24

Replace the IPM. Refer to Control Module References for replacement, setup and programming.

Did you complete the replacement?

 

Go to Step 26

--

25

Replace the inoperative high beam headlamp bulb. Refer to Headlamp Bulb Replacement .

Did you complete the replacement?

 

Go to Step 26

--

26

Operate the system in order to verify the repair.

Did you correct the condition?

 

System OK

Go to Step 2