GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C-Series Medium Duty Truck B7 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Daytime Running Lamps (DRL) Indicator Inoperative

Step

Action

Yes

No

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

1

Did you review the daytime running lights (DRL) description and operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Lighting Systems

2
  1. Turn ON the ignition switch, with the engine OFF.
  2. Place the headlamp switch in the OFF position.
  3. Disengage the parking brake.

Does the DRL Indicator illuminate?

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

Go to Step 3

3

Are the DRLs illuminated?

Go to Step 4

Go to Daytime Running Lamps (DRL) Inoperative

4
  1. Turn OFF the ignition switch.
  2. Disconnect the driver information center (DIC) connector C2.
  3. Probe the ignition positive voltage circuit of the DRL indicator with a test lamp that is connected to a good ground.
  4. Turn ON the ignition switch, with the engine OFF.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5
  1. Turn OFF the ignition switch.
  2. Disconnect the DIC connector C1.
  3. Connect a test lamp between the ignition positive voltage circuit of the DRL indicator and the DRL relay control circuit of the DRL indicator.
  4. Turn ON the ignition switch, with the engine OFF.

Does the test lamp illuminate?

Go to Step 6

Go to Step 8

6

Inspect for poor connections at the harness connectors of the DIC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

7

Repair an open, high resistance, or short to ground in the ignition positive voltage circuit of the DRL indicator. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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8

Repair an open or high resistance in the DRL relay control circuit of the DRL indicator. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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9

Replace the DIC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console.

Did you complete the replacement?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3