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B0840

B0840: Airbag System Circuit Malfunction

Fix Cost
$200 - $800
Parts & Labor
Difficulty
4/5
Hard
1-2 hours
DIY Possible?
❌ No
Pro recommended
Category
Body
System

📖 What Does B0840 Mean?

The airbag system circuit has malfunctioned, preventing the airbag from deploying in the event of a crash. This code may also indicate a problem with the airbag sensor or wiring.
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Symptoms

  • Airbag warning light on dashboard
  • airbag system not functioning
  • crash sensor not triggering
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Common Causes

  • Faulty airbag sensor
  • damaged wiring
  • blown fuse
  • faulty airbag control module
Fix Guide
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Possible Solutions

1. Check and replace blown fuses. 2. Inspect and repair damaged wiring. 3. Replace faulty airbag sensor. 4. Update airbag control module software.

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Common Questions About B0840

Q

Can I drive with code B0840?

A

No, it is not recommended. Seeing code B0840 indicates a serious issue that could damage your engine or transmission if ignored. You should stop driving and have it inspected immediately.

Q

How much does it cost to fix B0840?

A

The estimated repair cost for code B0840 is between $200 and $800. This includes parts and labor for most makes and models.

Q

Is this code easy to fix myself?

A

This repair is considered difficult. It may require specialized tools or significant disassembly. Professional help is recommended if you aren't an experienced DIYer.

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Need a Pro?

Complex codes like B0840 can be tricky. Don't risk it if you're unsure.

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Related Diagnostic Codes

Other codes that may appear with B0840

💡 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