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 B2648 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 open or short to battery positive voltage in the DRL ambient light sensor signal circuit.
- The ambient light sensor is intermittently open.
- The BCM is intermittently open or shorted to battery positive voltage.