Diagnostic Aids

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

If the DTC B2647 is a history DTC, the fault may be intermittent. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS
The following conditions may cause an intermittent condition to occur:
- An intermittent short to ground in the DRL ambient light sensor signal circuit.
- The ambient light sensor is intermittently shorted to ground.
- The BCM is intermittently shorted to ground.

Fig 1: DTC B2647 Diagnostic Table (1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B2647 Diagnostic Table (2 Of 2)

Courtesy of GENERAL MOTORS CORP.