GM Service Manual Online
For 1990-2009 cars only

Headlamps Inoperative - High Beams Standard

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the high beam headlamps are inoperative.

Do the headlamps operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Move the headlamp switch to the HEAD position.
  2. Place the headlamp dimmer switch in the HIGH BEAM position.
  3. Connect a test lamp from CKT 524 (PPL), pin E11 at the multifunction switch to ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 4

4

Locate and repair the open or high resistance in CKT 524 (PPL) between the headlamp high beam bulbs and the multifunction switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 10

--

5

  1. Ensure that the headlamp switch is in the HEAD position.
  2. Ensure that the headlamp dimmer switch is in the HIGH BEAM position.
  3. Connect a fused jumper from C211 cavity E11 to cavity E13.

Do the high beams illuminate?

--

Go to Step 6

Go to Step 7

6

Replace the multifunction switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Standard or Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle Steering Wheel and Column - Tilt.

Is the repair complete?

--

Go to Step 10

--

7

Remove the Headlamp Grounding Relay from the Body Relay Block and install a fused jumper between terminal 30 and terminal 87A of the relay socket.

Do the high beams illuminate?

--

Go to Step 9

Go to Step 8

8

Locate and repair open in CKT 10 (YEL) or CKT 1850 (BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 10

--

9

Replace the Headlamp Grounding Relay.

Is the repair complete?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Headlamps Inoperative - High Beams Envoy/Diamond Edition 1SK

Step

Action

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the high beam headlamps are inoperative.

Do the headlamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Turn the headlamp switch to HEAD with the multifunction headlamp dimmer switch in the high beams position.

Using the scan tool, check the High Beam Switch Input.

Does the scan tool show the switch is ON?

Go to Step 5

Go to Step 4

4

Test the following circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems:

    • Headlamp high beam relay control
    • Multifunction headlamp dimmer switch ground

Did you find and correct the condition?

Go to Step 12

Go to Step 10

5

  1. Remove the high beam relay from the body relay block.
  2. Connect a test light to ground and test for voltage at the headlamp relay supply coil voltage circuit terminal in the high beam relay socket. Refer to Electrical Center Identification Views and Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6

Test the headlamp relay coil supply voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

7

Install a fused jumper between the high beam relay battery positive voltage circuit terminal and headlamp supply voltage circuit terminal at the relay socket. Refer to Electrical Center Identification Views in Wiring Systems.

Do the high beam headlamps operate?

Go to Step 11

Go to Step 8

8

Repair the open, high resistance or short to ground in one of the following circuits. Refer to Wiring Repairs in Wiring Systems:

    • Battery positive voltage circuit
    • Headlamp supply voltage circuit

Did you complete the repair?

Go to Step 12

--

9

Important:: Perform the setup procedure for the Body Control Module (BCM).

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 12

--

10

Replace the Multifunction Switch (High Beam/Flash-to-Pass Switch). Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle Steering Wheel and Column - Tilt.

Is the repair complete?

Go to Step 12

--

11

Replace the high beam relay.

Did you complete the repair?

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3