Ambient Light Sensor Circuit High
The ambient light sensor circuit is registering a higher voltage than expected.
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What it means (plain English)
The light sensor's readings are too high, meaning it thinks there's way more light than there actually is, which can mess with systems like auto-dimming headlights.
What the computer is actually seeing
The Body Control Module (BCM) sees a voltage from the ambient light sensor that exceeds 4.5 volts when it should be below this range in normal conditions.
What a healthy reading looks like
The sensor should output a voltage between 0.5 and 3.5 volts depending on ambient light conditions; a reading above 4.5 volts indicates a fault.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the ambient light sensor wiring and connectors for damage or corrosion; fix if you find any issues.
- 22. Measure the voltage at the ambient light sensor connector: it should be between 0.5 and 3.5 volts. If it's over 4.5 volts, continue to step 3.
- 33. Check for a short in the wiring harness. Disconnect the sensor and measure voltage coming from the wiring harness. If it's over 4.5 volts, repair the harness as needed.
- 44. Replace the ambient light sensor if wiring checks out and voltage is still high when connected.
Common causes
- Faulty ambient light sensor
- Wiring issues in the sensor circuit
- Short circuit to power in the sensor circuit
- Poor ground connection for the sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
Yes, it's safe to drive, but automatic lighting features may not function properly.
Will the code come back after clearing?
It could if the underlying issue isn't fixed; check sensor and wiring thoroughly.
Why does this code often pair with other codes?
Issues with the ambient light sensor can affect other systems, causing multiple codes to trigger.
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