Diagnostic Aids

WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

If DTC B2601 is set along with DTC B2602, test the DRL relay control circuit between the BCM and the DRL relay for a short to ground.
The park brake must be not applied 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 AND POOR CONNECTIONS in Wiring Systems.