Automatic Headlight Control Sensor Malfunction
The B0086 code means the vehicle's onboard diagnostic system has detected: Automatic Headlight Control Sensor Malfunction. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $30 - $200 (parts and labor)
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Common Symptoms
- Auto headlights do not turn on at dusk
- Headlights activate in bright daylight
- Auto headlight feature not working
- Erratic headlight switching
Probable Causes (Ranked by Likelihood)
- Failed ambient light sensor Very High
- Dirty or obstructed sensor lens High
- BCM auto headlight control fault Moderate
- Wiring fault between sensor and BCM Low
Step-by-Step Diagnostic Procedure
-
Inspect sensor for obstructions
-
Clean sensor lens and test
-
Read BCM sensor values
-
Check sensor-to-BCM wiring
Frequently Asked Questions
Where is the sensor?
On top of the dashboard near the windshield.
Can a dirty windshield affect it?
Yes, tinting or dirt can obstruct the sensor.
Can I override the auto system?
Yes, use the headlight switch for manual control.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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