B0066 low

Left License Plate Light Circuit Malfunction

The B0066 code means the vehicle's onboard diagnostic system has detected: Left License Plate Light Circuit Malfunction. This is a low severity code.

My Garage →
Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$5 - $80 (parts and labor)
Read Body Codes
BlueDriver Bluetooth Pro Scanner

Basic scanners skip body codes entirely. BlueDriver reads airbag, HVAC, lighting, and BCM codes through your phone.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

  • Left license plate light not illuminating
  • Dark license plate at night
  • Police citation for unlit plate
  • Failed vehicle inspection

Probable Causes (Ranked by Likelihood)

  • Burned out license plate bulb Very High
  • Corroded socket from road spray High
  • Cracked or water-filled housing Moderate
  • Damaged ground wire at plate bracket Low

Step-by-Step Diagnostic Procedure

  1. Inspect license plate bulb

  2. Check socket for corrosion

  3. Verify ground at plate bracket

  4. Test voltage at connector

Frequently Asked Questions

Can I get a ticket for this?

Yes, all states require plate illumination at night.

Why do license plate lights fail often?

They are mounted low and exposed to road spray, salt, mud, and debris.

Are LED plate lights legal?

Yes, in most states as long as they emit white light.

Sources

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

Explore More

Was this helpful?

Share carcodefinder.com with a friend who needs to decode their check engine light.