← View Generic B3739 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2018 BMW X5

B3739: B3739: Power Window Relay Circuit Malfunction

on 2018 BMW X5

Fix Cost
$50 - $150
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 B3739 Mean on 2018 BMW X5?

The power window relay circuit has malfunctioned, preventing the windows from functioning properly.
⚠️

Symptoms

  • • Windows do not move
  • • or move intermittently
  • • when switches are activated.
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Common Causes

  • • Faulty power window relay
  • • wiring issues
  • • or faulty window switch.
🛠️

How to Fix B3739 on 2018 BMW X5

1. Disconnect battery to reset system. 2. Check and clean wiring connections. 3. Replace faulty power window relay. 4. Test window operation.

🔧

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Parts for 2018 BMW X5

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Related Diagnostic Codes

Other codes that may appear with B3739

B3737 Sequential Code

B3737: Climate Control Temperature Sensor Malfunction

Medium
B3738 Sequential Code

B3738: Door Locks Actuator Malfunction

Medium
B3740 Sequential Code

B3740: Seat Position Sensor Circuit Malfunction

Medium
B3741 Sequential Code

B3741: Exterior Lighting Malfunction

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