B0093 moderate

Exterior Lighting Control Module Failure

The B0093 code means the vehicle's onboard diagnostic system has detected: Exterior Lighting Control Module Failure. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$150 - $600 (parts and labor)
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Common Symptoms

  • Multiple exterior lights not working
  • Module not responding to BCM
  • Exterior light codes in BCM
  • Random light behavior

Probable Causes (Ranked by Likelihood)

  • Internal module failure Very High
  • Water intrusion into module High
  • Power supply fault to module Moderate
  • BCM software compatibility issue Low

Step-by-Step Diagnostic Procedure

  1. Check module power and ground

  2. Inspect for water damage

  3. Attempt module communication

  4. Replace and configure module

Frequently Asked Questions

Can water damage cause failure?

Yes, water on the circuit board causes corrosion and shorts.

Does the new module need programming?

Yes, using dealer-level diagnostic equipment.

Can a failed module drain the battery?

Yes, it can stay awake on the network drawing excessive current.

Sources

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

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