Circuit Description
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.
This DTC indicates that a short to ground or open condition exists in the ambient light sensor circuit. DTC B2647 will set if all of the following conditions occur:
- Automatic Lighting Control (ALC) is enabled.
- Ignition 1 is active.
- Ambient light sensor is shorted for 5 seconds.
When DTC sets, the head lights will be on at full intensity. DTC will clear from history after ignition switch is cycled on and off 100 times with no faults present. DTC can also be cleared using scan tool.