GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Envoy - 4WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Headlamps Inoperative - High Beams

Headlamps Inoperative - High Beams Standard

Step

Action

Value(s)

Yes

No

1

Did you perform the DRL System Check?

--

Go to Step 2

Go to Daytime Running Lights (DRL) System Check

2

Use the scan tool in order to read the body control module (BCM) current trouble codes.

Does the scan tool show any DTCs?

--

Go to Diagnostic Trouble Code (DTC) List/Type in Body Control System

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.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 4

4

Locate and repair the open in CKT 524 (PPL) between the headlamp high beam bulbs and the multifunction switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

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 Daytime Running Lights (DRL) System Check

6

Replace the multifunction switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

Headlamps Inoperative - High Beams Envoy

Step

Action

Value(s)

Yes

No

1

Did you perform the DRL System Check?

--

Go to Step 2

Go to Daytime Running Lights (DRL) System Check

2

Perform the BCM Diagnostic System Check.

Is the BCM system OK?

--

Go to Step 3

Go to the Applicable DTC in Body Control System

3

Connect a test lamp between ground and each test point on the back of the HI BEAM fuse in the underhood fuse block.

Does the test lamp illuminate at both of the test points?

--

Go to Step 7

Go to Step 4

4

Does the test lamp illuminate at one of the test points?

--

Go to Step 5

Go to Step 6

5

Locate and repair a short to ground in one of the following circuits:

    • CKT 3640 (ORN) in the high beam relay
    • CKT 1346 (LT BLU between the high beam relay and the underhood fuse block

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

6

Locate and repair the power source to the HI BEAM fuse. Refer to

Cell 10: HI BEAM, LD LEV, DRL Fuses and Low Beam Relay (Envoy Only)


Object Number: 379920 Size: FS
Power and Grounding Connector End Views
Power and Grounding Components
Cell 10: ECM B Fuse and Horn, Rear Defogger Relays
Cell 10: MIR/LKS, FOG LP Fuses and DRL, Headlamp Power Relays
Cell 10: B+ Buss Bar
 in Wiring Systems.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

7
  1. Disconnect the high beam relay.
  2. Connect a fused jumper between cavity 30 and cavity 87 at the high beam relay socket.

Do the high beams illuminate?

--

Go to Step 9

Go to Step 8

8

Locate and repair an open in CKT 1346 (LT BLU) between the high beam relay and the underhood fuse block.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

9
  1. Connect a test lamp between CKT 352 (WHT), cavity 85 at the high beam relay and ground.
  2. Move the headlamp switch to the ON position.
  3. Move the multifunction switch lever to the HIGH BEAMS position.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 10

10
  1. Disconnect the body control module (BCM) connector C3.
  2. Connect a J 39200 digital multimeter (DMM) between CKT 352 (WHT), cavity 85 at the high beam relay and CKT 352 (WHT), cavity A8 at BCM connector C3.

Is the resistance less than the specified value?

1 ohms

Go to Step 19

Go to Step 11

11

Locate and repair an open in CKT 352 (WHT).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

12
  1. Connect a test lamp between CKT 1969 (BLK/WHT), cavity 86 of the high beam relay socket and battery voltage.
  2. Move the multifunction switch lever to the HIGH BEAMS position.

Does the test lamp illuminate in the HIGH BEAMS position?

--

Go to Step 13

Go to Step 14

13

Replace the high beam relay.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

14
  1. Reinstall the high beam relay.
  2. Use a fused jumper in order to backprobe between CKT 1969 (BLK/WHT), cavity E11 at C211 and ground.
  3. Move the headlamp switch to the ON position.

Do the high beams illuminate?

--

Go to Step 16

Go to Step 15

15

Locate and repair the open in CKT 1969 (BLK/WHT).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

16
  1. Use a fused jumper in order to backprobe between CKT 1850 (BLK), cavity E13 at C211 and ground.
  2. Move the multifunction switch lever to the HIGH BEAMS position.

Do the high beams illuminate?

--

Go to Step 17

Go to Step 18

17

Locate and repair an open in CKT 1850 (BLK).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

18

Replace the high beam switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

19
  1. Install the scan tool.
  2. Select BODY APPLICATION: DATA.
  3. Move the headlamp switch to the ON position.
  4. Observe the Headlamp Request parameter.

Does the Headlamp Request display show the specified value?

ACTIVE

Go to Step 20

Go to Step 21

20

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

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

21

Locate and repair the open in CKT 103 (WHT) between the underhood fuse block and the BCM.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--