Front Left Courtesy Light Circuit Malfunction
The B0139 code means the vehicle's onboard diagnostic system has detected: Front Left Courtesy Light Circuit Malfunction. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- easy
- Estimated cost
- $10 - $150 (parts and labor)
Basic scanners skip body codes entirely. BlueDriver reads airbag, HVAC, lighting, and BCM codes through your phone.
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Common Symptoms
- Door courtesy light not illuminating
- No step light when door opens
- Courtesy light stays on after door closes
- Courtesy light flickers
Probable Causes (Ranked by Likelihood)
- Burned out courtesy light LED Very High
- Failed courtesy light driver High
- Corroded courtesy light connector Moderate
- Door module courtesy output fault Low
Step-by-Step Diagnostic Procedure
-
Inspect courtesy light LED
-
Check connector for corrosion
-
Test voltage with door open
-
Scan door module for DTCs
Frequently Asked Questions
What is a courtesy light?
A light in the door trim illuminating the step area when the door opens for safe entry and exit.
Is it different from a puddle light?
A puddle light is under the mirror pointing outside. A courtesy light is inside the door pointing at the floor.
Can I replace just the LED?
Some have replaceable LEDs; others require the full assembly.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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