DTC B2648: Ambient Lamp Sensor Circuit High: Testing
WARNING: This page is about a different car, the 1999 Pontiac Grand Am and 1999 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If circuit is shorted to ground, fuse will blow. Check fuse before performing diagnostics.
- Perform BCM DIAGNOSTIC SYSTEM CHECK under SYSTEM TESTS. Go to next step.
- Disconnect ambient light sensor. Sensor is located on top of the instrument panel near defroster vents. Disconnect BCM connector C2. Using DVOM, measure voltage between ambient light sensor connector terminal "B" (Yellow/Black wire) and ground. See WIRING DIAGRAMS . If zero volts is indicated, go to step 4 . If any voltage is indicated, go to next step.
- Repair short to voltage in Yellow/Black wire between BCM and ambient light sensor. After repairs, go to step 5 .
- Replace ambient light sensor. After repairs, go to next step.
- Using scan tool, clear DTCs. If DTC does not reset, go to step 7 . If DTC resets, go to next step.
- Replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. After repairs, go to next step.
- Using scan tool, clear DTCs. Go to BCM DIAGNOSTIC SYSTEM CHECK under SYSTEM TESTS.