DTC B2647, Light Sensor Short To Ground/Open

WARNING: This page is about a different car, the 1997 Oldsmobile Cutlass and 1997 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

If BFC diagnostic system check was performed, go to next step. If BFC diagnostic system check was not performed, go to BFC DIAGNOSTIC SYSTEM CHECK .
Disconnect ambient light sensor from top of instrument panel. Disconnect BFC 24-pin, Gray connector C2. Using DVOM, check resistance between ambient light sensor harness terminal "B" (Yellow/Black wire) and ground. If resistance is infinite, go to step 4). If resistance is not infinite, go to next step.
Repair short to ground in Yellow/Black wire between ambient light sensor and BFC connector C2. Go to step 11).
Using DVOM, check resistance between ambient light sensor harness terminal "B" (Yellow/Black wire) and BFC harness connector C2, terminal A3 (Yellow/Black wire). If resistance is 0-2 ohms, go to step 6). If resistance is not 0-2 ohms, go to next step.
Repair open in Yellow/Black wire between ambient light sensor and BFC connector C2. Go to step 11).
Using DVOM, check resistance between ambient light sensor harness terminal "A" (Light Green/Black wire) and ground. If resistance is infinite, go to step 8). If resistance is not infinite, go to next step.
Repair short to ground in Light Green/Black wire between ambient light sensor and BFC connector C2. Go to step 11).
Replace ambient light sensor. Go to next step.
Clear DTCs. Check for DTCs. If DTC B2647 exists, go to next step. If DTC B2647 does not exist, go to step 11).
Replace BFC. See REMOVAL & INSTALLATION . Go to next step.
Clear DTCs. Perform BFC DIAGNOSTIC SYSTEM CHECK .