Diagnostic Aids
WARNING: This page is about a different car, the 2004 Pontiac Sunfire and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
- The park brake must be unapplied and the transaxle must be in gear for the DRLs to operate properly.
- If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
DTC B2603
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics | |||
| 1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems |
| 2 |
|
Go to Step 3 | Go to Step 4 |
| 3 |
|
Go to Step 4 | Go to Step 5 |
| 4 | Inspect for poor connections at the DRL relay. 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 9 | Go to Step 7 |
| 5 | Inspect for poor connections at the harness connector of the body control module. 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 9 | Go to Step 8 |
| 6 | Repair a short to voltage in the DRL relay control circuit. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you complete the repair? |
Go to Step 9 | - |
| 7 | Replace the DRL relay. Did you complete the replacement? |
Go to Step 9 | - |
| 8 |
IMPORTANT:
Perform the set up procedure for the body control module. Replace the body control module. Refer to Body Control Module Replacement
in Body Control System.Did you complete the replacement? |
Go to Step 9 | - |
| 9 |
|
Go to Step 2 | System OK |