Daytime Running Lamps (DRL) Inoperative, Headlamp Switch Operates Normally. Chevrolet S10 Pickup

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1998 🢒 S10 Pickup - 2WD 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Daytime Running Lamps (DRL) Inoperative, Headlamp Switch Operates Normally

Daytime Running Lamps (DRL) Inoperative, Headlamp Switch Operates Normally 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 current body control module (BCM) diagnostic trouble codes (DTCs). Does the scan tool show any DTCs?	--	Go to Diagnostic System Check - Body Control System in Body Control Systems	Go to Step 3
3	Disconnect the DRL relay. Turn the ignition switch to the ON position. Do not start the engine. Connect a fused jumper wire between the DRL relay terminal 1-2 and terminal 3-5. Do the DRLs illuminate?	--	Go to Step 4	Go to Step 5
4	Replace the DRL relay. Is the repair complete?	--	Go to Daytime Running Lights (DRL) System Check	--
5	Using the J 39200 and the connector test adapter kit, test terminal 2 of the DRL relay socket in the underhood fuse block for voltage. Is voltage present?	Battery Voltage	Go to Step 7	Go to Step 6
6	Replace the UBEC. Is the repair complete?	--	Go to Daytime Running Lights (DRL) System Check	--
7	Install the DRL relay. Disconnect the headlamp grounding relay. Disconnect the BCM connector C1. Turn the ignition switch to the ON position. Do not start the engine. Measure the voltage at connector C1 cavity A11. Is voltage present?	--	Go to Step 9	Go to Step 8
8	Locate and repair the open in CKT 592. Is the repair complete?	--	Go to Daytime Running Lights (DRL) System Check	--
9	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	--

Daytime Running Lamps (DRL) Inoperative, Headlamp Switch Operates Normally Envoy

Step

Action

Value(s)

Yes

Did you perform the DRL System Check?

Go to Step 2

Go to Daytime Running Lights (DRL) System Check

Turn the ignition to the RUN position.
Connect a test lamp between the following components:

•

Ground

•	Each test point on the back of the IGN E fuse in the UBEC

Does the test lamp light at both test points?

Go to Step 7

Go to Step 3

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

Go to Step 4

Go to Step 14

Remove the DRL relay.
Replace the IGN E fuse.
Turn the ignition to the RUN position.

Does the IGN E fuse open?

Go to Step 5

Go to Step 6

Replace the underhood bussed electrical center (UBEC).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Replace the daytime running lamps (DRL) relay.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a test lamp between the following components:

•

Ground

•	Each test point on the back of the DRL fuse

Does the test lamp light at both test points?

Go to Step 19

Go to Step 8

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

Go to Step 10

Go to Step 9

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

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Remove the daytime running lamps (DRL) relay.
Replace the DRL fuse.
Turn the ignition to the RUN position.

Does the DRL fuse open?

Go to Step 5

Go to Step 11

Connect a fused jumper with at least a 20 amp fuse installed between the following cavities at the daytime running lamps relay:

•

Cavity 5

•

Cavity 3

Turn the ignition to the RUN position.

Does the DRL fuse open?

Go to Step 12

Go to Step 13

Locate and repair a short to ground in CKT 1193 (LT GRN).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Replace the daytime running lamps (DRL) relay.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a test lamp between the following components:

•

Ground

•	Each test point on the back of the IGN A fuse

Does the test lamp light at both test points?

Go to Step 18

Go to Step 15

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

Go to Step 16

Go to Step 17

Locate and repair a short to ground in the following components, between IGN A fuse and IGN E fuse:

•	CKT 242 (RED)

•	CKT 3 (PNK)

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair the power feed to IGN A fuse. Refer to Power Distribution Schematics in Wiring Systems.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair an open in the following components, between IGN A fuse and IGN E fuse:

•	CKT 242 (RED)

•	CKT 3 (PNK)

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Remove the daytime running lamps relay.
Connect a fused jumper between the following components of the DRL relay socket:

•

Cavity 5

•

Cavity 3

Do the daytime running lamps light?

Go to Step 37

Go to Step 20

Connect a test lamp between the following components:

•

Ground

•	Each test point on the back of the RT HI fuse

Does the test lamp light at both test points?

Go to Step 28

Go to Step 21

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

Go to Step 22

Go to Step 23

Replace the RT HI fuse.
Inspect CKT 311 (LT GRN/BLK) for an intermittent short to ground. Repair as necessary.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Inspect the RH high beam bulb.

Is the bulb open?

Go to Step 24

Go to Step 25

Replace the RH high beam bulb.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a J 39200 DMM between the following components:

•	Cavity 3 at the DRL relay socket

•	CKT 1193 (LT GRN), cavity B at the RH high beam bulb connector

Is the resistance less than the specified value?

1.0 ohms

Go to Step 27

Go to Step 26

Locate and repair an open in CKT 1193 (LT GRN).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair an open in CKT 311 (LT GRN/BLK).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a test lamp between the following components:

•

Ground

•	Each test point on the back of the LT HI fuse.

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

Go to Step 32

Go to Step 29

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

Go to Step 31

Go to Step 30

Replace the underhood bussed electrical center (UBEC).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair a short to ground in CKT 711 (DK GRN/WHT).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Inspect the left high beam bulb.

Is the bulb filament open?

Go to Step 33

Go to Step 34

Replace the left high beam bulb.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a test lamp between the following components:

•	CKT 711 (DK GRN/WHT) terminal B of the left high beam connector

•

Ground

Does the test lamp light?

Go to Step 36

Go to Step 35

Locate and repair an open in CKT 711 (DK GRN/WHT).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair an open in CKT 150 (BLK).

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Connect a scan tool to the vehicle.
Inspect the system. Refer to Diagnostic System Check - Body Control System in Body Control System. Return here if the system check reports SYSTEM NORMAL.
Select Body Control Module.
Read the Daytime Running Lamps status.

Does the Daytime Running Lamps status display the specified value?

ACTIVE

Go to Step 44

Go to Step 38

Select Body Control Module.
Read the Park Brake Switch status.

Does the Park Brake Switch status display the specified value?

SET

Go to Step 39

Go to Step 43

Inspect the park brake in order to ensure that the park brake is not set.
Disconnect the park brake switch connector.
Select body control module.
Read the Park Brake Switch status.

Does the Park Brake Switch status display the specified value?

SET

Go to Step 40

Go to Step 42

Locate and repair a short to ground in CKT 80 between the following components:

•	The park brake switch

•	Body control module (BCM) connector C1

Is the repair complete?

Go to Step 41

If the wire is OK, 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

Adjust or replace the park brake switch as necessary.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Replace the body control module. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Re-install the DRL relay.
Use a fused jumper in order to backprobe between the following components:

•	CKT 592 (LT GRN/BLK), cavity A11 connector C1 at the body control module

•

Ground

Do the daytime running lamps light?

Go to Step 43

Go to Step 45

Remove the DRL relay.
Connect a test lamp between the following components:

•	Cavity 2 at the DRL relay socket

•

Cavity 1

•	Use the J 35616-A in order to turn the ignition to RUN.

•	Verify the active DRL status.

Does the test lamp light?

Go to Step 46

Go to Step 47

Replace the DRL relay.

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check

Locate and repair an open in CKT 592 (LT GRN/BLK) between the following components:

•	DRL relay cavity 2

•	Body control module

Is the repair complete?

Go to Daytime Running Lights (DRL) System Check