Diagnostic Aids
WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
- If the DTC B2603 is a history DTC, the fault may be intermittent. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.
- The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to battery in the LF turn signal lamp supply voltage circuit or the LF turn signal switch signal circuit
- The BCM is intermittently shorted to battery.