Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
This DTC indicates that a short to battery voltage condition exists in the ambient light sensor circuit. DTC B2648 will set if all of the following conditions occur:
- Automatic Lighting Control (ALC) is enabled.
- Ignition 1 is active.
- Ambient light sensor is shorted to battery voltage for 5 seconds.
When DTC sets, the check gauges chime will sound and the SERVICE VEHICLE SOON indicator will come on. BCM will go to sleep and wake up when DTC is repaired. 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.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.