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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Sonoma Pickup - 2WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Daytime Running Lamps (DRL) Headlamps Inoperative

Daytime Running Lamps (DRL) Headlamps Inoperative 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.

Is DTC B2575, B2577, or B2600 set as a current code?

--

Go to Diagnostic System Check - Body Control System in Body Control System

Go to Step 3

3
  1. Place the headlamp switch in HDLP position.
  2. Connect a test lamp between the following components:
    3. • UBEC terminal B1, connector C4 to ground
    • UBEC terminal B2, connector C4 to ground

Does the test lamp light at both locations?

--

Go to Step 13

Go to Step 4

4

Connect a test lamp from CKT 1940 (ORN) at the headlamp switch to ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

5

Locate and repair the open in CKT 1940 (ORN) between the IP Fuse Block and the headlamp switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

6

Connect a test lamp between CKT 352 (WHT) at the headlamp switch to ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 7

7

Replace the headlamp switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

8

Connect a test lamp from pin 2 of the Headlamp Power Relay to ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 9

9

Locate and repair the open in CKT 352 (WHT) between the headlamp switch and the Headlamp Power Relay.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

10
  1. Remove the Headlamp Power Relay.
  2. Connect a test lamp from pin 2 to pin 1 of the Headlamp Power Relay socket.

Does the test lamp light?

--

Go to Step 11

Go to Step 12

11

Replace the Headlamp Power Relay.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

12

Locate and repair the open in CKT 350 (BLK) between the Underhood Bussed Electrical Center (UBEC) and G102.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

13
  1. Disconnect C211 at the steering column.
  2. Connect a fused jumper between terminal E12 (YEL) and terminal E13 (YEL) in order to bypass the multifunction switch.

Do the headlamps light?

--

Go to Step 14

Go to Step 17

14

Inspect the integrity of the terminals.

Are the terminals in need of repair?

--

Go to Step 15

Go to Step 16

15

Repair the terminals as necessary.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

16

Replace the multifunction switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

17
  1. Remove the Headlamp Ground Relay.
  2. Connect an ohmmeter between the following components:
    3. • Pin 3 at the Headlamp Ground Relay
    • Pin E13 at C211

Is the resistance greater than the specified value?

1 ohms

Go to Step 18

Go to Step 19

18

Locate and repair the open in CKT 10 (YEL).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

19
  1. Reinstall C211.
  2. Connect an ohmmeter between relay terminal 3 and terminal 4 of the Headlamps Ground Relay.

Is the resistance greater than the specified value?

1 ohms

Go to Step 20

Go to Step 21

20

Locate and repair the open in CKT 350 (BLK).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

21

Replace the Headlamp Ground Relay.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

Daytime Running Lamps (DRL) Headlamps Inoperative 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
  1. Disconnect the low beam relay.
  2. Connect a J 39200 digital multimeter (DMM) between cavity 30 at low beam relay and ground.

Does the voltage equal the specified value?

B+

Go to Step 3

Go to Step 19

3
  1. Connect a test lamp between low beam relay cavity 85 and ground.
  2. Turn the headlamp switch to the HEAD position.

Does the test lamp light?

--

Go to Step 4

Go to Step 10

4
  1. Temporarily remove the RT HIGH BEAM fuse.
  2. Remove the low beam relay.
  3. Connect a J 39200 DMM from UBEC cavity 86 to ground.
  4. Test for continuity.

Is the resistance less than the specified value?

1 ohms

Go to Step 5

Go to Step 9

5
  1. Re-install the low beam relay.
  2. Turn the headlamp switch to the HEAD position.
  3. Connect a test lamp between the following components:
    4. • Ground
    • Each exposed test point on the back of both the RT LOW and LT LOW fuses

Does the test lamp light on at least one test point on each fuse?

--

Go to Step 25

Go to Step 6

6
  1. Disconnect the low beam relay.
  2. Connect a J 39200 DMM between the following components:
    3. • Cavity 87
    • Each exposed test point on the back of both the RT LOW and LT LOW fuses

Is the resistance less than or equal to the specified value at each fuse?

1 ohms

Go to Step 7

Go to Step 8

7

Replace the low beam relay.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

8

Replace the underhood bussed electrical center (UBEC).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

9

Locate and repair the open in CKT 350 (BLK), in the terminals or in the UBEC.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

10

Connect a test lamp between the following components:

    • Ground
    • Both exposed test points on the back of the HDLP SW fuse.

Does the test lamp light at both test points?

--

Go to Step 14

Go to Step 11

11

Does the test lamp light at either test point?

--

Go to Step 12

Go to Step 13

12
  1. Locate and repair the short to ground in the circuit between the following components:
    2. • The HDLP SW fuse
    • The low beam relay
  2. Replace the HDLP SW fuse.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

13

Locate and repair the open in power feed to HDLP SW fuse. Refer to Power Distribution Schematics in Wiring Systems.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

14
  1. Disconnect the headlamp switch.
  2. Connect a fused jumper between the following components:
    3. • CKT 940 (ORN) cavity D
    • CKT 103 (WHT) cavity C at the headlamp switch connector
  3. Connect a test lamp between the low beam relay cavity 86 and ground.

Does the test lamp light?

--

Go to Step 15

Go to Step 16

15

Replace the headlamp switch.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

16

Connect a test lamp between ground and CKT 1940 (ORN) cavity D at the headlamp switch connector.

Does the test lamp light?

--

Go to Step 17

Go to Step 18

17

Locate and repair the open in CKT 103 (WHT).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

18

Locate and repair the open in CKT 1940.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

19

Inspect the charging system. Refer to Starting System Check or Charging System Check in Engine Electrical.

Is the charging system functioning properly?

--

Go to Step 21

Go to Step 20

20

Repair the charging system.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

21
  1. Connect test leads and test lead adapters to the J 39200 .
  2. Record this value and subtract it from all resistance readings. If the meter you are using has a zeroing function, zero the meter.
  3. Disconnect the battery positive cable.
  4. Connect a J 39200 between the following components:
    5. • The battery positive cable
    • Cavity 30 at the low beam relay.

Is the resistance less than or equal to the specified value?

1 ohms

Go to Step 23

Go to Step 22

22
  1. Locate and repair high resistance between the following components:
    2. • The battery positive cable
    • The low beam relay
  2. If all connections are clean and tight, replace the underhood bussed electrical center (UBEC).

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

23
  1. Reconnect the battery positive cable.
  2. Reconnect the low beam relay.
  3. Turn the headlamp switch to the HEAD position.

Do the HID headlamps illuminate?

--

Go to Daytime Running Lights (DRL) System Check

Go to Step 24

24
  1. Remove the underhood bussed electrical center (UBEC) and hold down the bolts.
  2. Flip the UBEC over.
  3. Disconnect connector C4.
  4. Inspect the cavities and terminals for damaged or corroded connections.

Are the connections OK?

--

Go to Step 25

Go to Step 26

25

Repair the poor connection(s) in connector C4.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

26
  1. Remove the cover from connector C4.
  2. Reconnect the connector C4 to UBEC.
  3. Connect a J 39200 between the following components:
    4. • Cavity 87 at the low beam relay socket
    • Terminal B2 on the underside of the UBEC at connector C4.

Does the resistance equal the specified value?

1.0 ohms (or negligible)

Go to Step 30

Go to Step 27

27

Inspect for a high resistance in the UBEC connection.

Is the connection OK?

--

Go to Step 29

Go to Step 28

28

Repair the high resistance in the UBEC connection.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

29

Replace the UBEC.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

30

Connect a J 39200 DMM between the following components:

  1. Cavity 87 at the low beam relay socket
  2. Terminal B2 on the underside of the UBEC at connector C4.

Does the resistance equal the specified value?

1.0 ohms (or negligible)

Go to Step 34

Go to Step 31

31

Inspect for a high resistance in the UBEC connection.

Is the connection OK?

--

Go to Step 33

Go to Step 32

32

Repair the high resistance in the UBEC connection.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

33

Replace the UBEC.

Is the repair complete?

--

Go to Daytime Running Lights (DRL) System Check

--

34
  1. Replace the low beam relay.
  2. Turn the headlamp switch to the HEAD position.

Do the HID headlamps illuminate?

--

Go to Daytime Running Lights (DRL) System Check

Go to Step 35

35

At this point, you have inspected every component and wiring path that is common to both HID headlamps.

You have inspected the system for an open or high resistance in the following components:

    • The power supply to the UBEC
    • The input from the headlamp switch to the low battery relay
    • The ground to the low beam relay
    • The low beam relay to each low beam fuse
    • The circuitry within the UBEC to each low beam fuse.

Since this symptom is for both HID, inoperative, it is unlikely that both of each of the following components is defective:

    • Both ballast grounds
    • Both arc tube assemblies
    • Both ballasts
    • Both sets of wiring

This possibility does exist, however.

Is all of the above statement true?

--

Go to Headlamps Inoperative - One Lamp

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