B0049 moderate

Right Headlight High Beam Circuit Malfunction

The B0049 code means the vehicle's onboard diagnostic system has detected: Right Headlight High Beam Circuit Malfunction. This is a moderate severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$10 - $350 (parts and labor)
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Common Symptoms

  • Right high beam headlight not working
  • Uneven high beam illumination
  • High beam indicator behaves abnormally
  • Reduced long-range visibility at night
  • Only left high beam functional

Probable Causes (Ranked by Likelihood)

  • Burned out right high beam bulb or filament Very High
  • Corroded right headlight connector High
  • High beam relay failure Moderate
  • Wiring fault in right high beam circuit Low

Step-by-Step Diagnostic Procedure

  1. Inspect right high beam bulb condition

  2. Check headlight connector for corrosion

  3. Test voltage at high beam terminal with beams activated

  4. Check high beam relay operation

  5. Verify wiring from relay to right headlight

Frequently Asked Questions

How do I know which filament is blown in a dual-filament bulb?

Look closely at the bulb. A dual-filament bulb has two thin wire elements inside. If one is broken or darkened while the other looks intact, the damaged filament is the failed one.

Is it safe to drive without high beams?

You can drive safely in well-lit areas without high beams, but on dark rural roads, high beams are essential for seeing hazards at a distance. Repair the issue before extended night driving.

Can a bad headlight switch cause this?

If both high beams are out, the multifunction switch or high beam relay could be the cause. If only one side is out, the issue is more likely the bulb, socket, or wiring on that side.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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