🚗 Vehicle-Specific Guide

This guide is customized for your 2020 Chevrolet SILVERADO 1500 PICKUP

B0678: B0678: Body Control Module (BCM) Security System Malfunction

on 2020 Chevrolet SILVERADO 1500 PICKUP

Fix Cost
$100 - $500
Parts & Labor
Difficulty
3/5
1-2 hours
DIY Possible?
❌ No
Pro recommended
Your Vehicle
2020 Chevrolet
SILVERADO 1500 PICKUP
⚠️

Important for 2020 Chevrolet SILVERADO 1500 PICKUP Owners

Before starting repairs, verify which engine your 2020 Chevrolet SILVERADO 1500 PICKUP has. Check your VIN or engine code to ensure you order the correct parts.

📖 What Does B0678 Mean on 2020 Chevrolet SILVERADO 1500 PICKUP?

The Body Control Module (BCM) has detected a security system malfunction, which may be caused by a faulty BCM, security system sensor, or wiring issue.
⚠️

Symptoms

  • Alarm system activation
  • door locks not functioning
  • or vehicle immobilization
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Common Causes

  • Faulty BCM
  • security system sensor
  • wiring issue
  • or battery voltage below 10V
🛠️

How to Fix B0678 on 2020 Chevrolet SILVERADO 1500 PICKUP

1. Check BCM fuse and replace if blown. 2. Inspect and clean security system sensors. 3. Check wiring for damage or corrosion and repair as needed. 4. Update BCM software if necessary. 5. Replace BCM if faulty.

🔧

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Related Diagnostic Codes

Other codes that may appear with B0678

💡 Why These Codes Are Related:

  • Similar Issues: Same root cause or component failure
  • Related Problems: Often occur together due to system interactions
  • Sequential Codes: Progressive failure stages or multiple sensors
  • Same System: Components within the same automotive system