B0004 critical

Passenger Frontal Stage 2 Deployment Control

The B0004 code means the vehicle's onboard diagnostic system has detected: Passenger Frontal Stage 2 Deployment Control. This is a critical severity code.

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Keep driving?
No -- stop driving
DIY difficulty
hard
Estimated cost
$300 - $1,100 (parts and labor)
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Common Symptoms

  • SRS warning light on dashboard
  • Airbag malfunction indicator illuminated
  • Passenger airbag second stage disabled
  • Warning chime active
  • Potential inspection failure

Probable Causes (Ranked by Likelihood)

  • Faulty stage 2 squib circuit in passenger airbag Very High
  • Damaged wiring harness under dashboard High
  • Corroded connector at passenger airbag module Moderate
  • SRS control module malfunction Moderate
  • Aftermarket dashboard modification interfering with wiring Low

Step-by-Step Diagnostic Procedure

  1. Pull all SRS DTCs with a compatible scanner

  2. Measure stage 2 squib resistance at passenger airbag connector

  3. Inspect wiring harness routing under dashboard for damage

  4. Check all SRS connectors for proper seating and corrosion

  5. Test SRS module outputs for proper voltage

Frequently Asked Questions

What is a stage 2 airbag squib?

A squib is the igniter that triggers airbag inflation. Stage 2 squibs provide additional deployment force during severe impacts for enhanced occupant protection.

Could this be caused by a previous accident?

Yes. If airbag components were not properly replaced or repaired after a prior collision, stage 2 circuits may have latent damage.

How long does the repair take?

Depending on the cause, repairs can take 1 to 4 hours. Replacing the airbag module itself is usually about 1-2 hours of labor.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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