← View Generic B1685 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2020 Chevrolet SILVERADO 1500 PICKUP

B1685: B1685: Body Control Module (BCM) Malfunction - Lighting

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 B1685 Mean on 2020 Chevrolet SILVERADO 1500 PICKUP?

The Body Control Module (BCM) has detected a malfunction in the lighting system, which may cause issues with the vehicle's exterior lights, such as the headlights, taillights, or turn signals.
⚠️

Symptoms

  • • Dim or inoperative exterior lights
  • • faulty turn signal indicators
  • • or erratic lighting behavior.
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Common Causes

  • • Faulty BCM
  • • wiring issues
  • • blown fuses
  • • or damaged lighting components.
🛠️

How to Fix B1685 on 2020 Chevrolet SILVERADO 1500 PICKUP

1. Check the BCM for any error codes or faults. 2. Inspect and repair or replace any damaged wiring or lighting components. 3. Check and replace any blown fuses. 4. Update the BCM software if necessary.

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Parts for 2020 Chevrolet SILVERADO 1500 PICKUP

BCM Shop ↗ wiring harness Shop ↗ lighting components Shop ↗ fuses Shop ↗

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Related Diagnostic Codes

Other codes that may appear with B1685

B1683 Sequential Code

B1683: Power Window Circuit Malfunction

Medium
B1684 Sequential Code

B1684: Seat Position Sensor Circuit Malfunction

Medium
B1686 Sequential Code

B1686: Immobilizer System Malfunction

Medium
B1687 Sequential Code

B1687: Audio System Fault

Medium

💡 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