← View Generic B1390 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2018 BMW X5

B1390: B1390: Body Control Module (BCM) Security System Malfunction

on 2018 BMW X5

Fix Cost
$100 - $500
Parts & Labor
Difficulty
3/5
1-2 hours
DIY Possible?
❌ No
Pro recommended
Your Vehicle
2018 BMW
X5
⚠️

Important for 2018 BMW X5 Owners

Before starting repairs, verify which engine your 2018 BMW X5 has. Check your VIN or engine code to ensure you order the correct parts.

📖 What Does B1390 Mean on 2018 BMW X5?

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

  • • Alarm sounds
  • • doors lock/unlock randomly
  • • security light flashes
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Common Causes

  • • Faulty BCM sensor
  • • wiring issue
  • • software glitch
  • • faulty security module
🛠️

How to Fix B1390 on 2018 BMW X5

1. Check BCM sensor connections and wiring for damage or corrosion. 2. Update BCM software if necessary. 3. Replace faulty BCM sensor or security module if necessary.

🔧

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Parts for 2018 BMW X5

BCM sensor Shop ↗ wiring harness Shop ↗

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Related Diagnostic Codes

Other codes that may appear with B1390

B1388 Sequential Code

B1388: Seat Switch Circuit Malfunction

Medium
B1389 Sequential Code

B1389: Body System Code - Lighting Malfunction

Medium
B1391 Sequential Code

B1391: Audio System Fault

Medium
B1392 Sequential Code

B1392: Airbag System Fault

High

💡 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