B0004

Driver Knee Bolster Deployment Control

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Airbag light is on
Knee airbag does not deploy during testing
Error B0004 displays when scanning

Causes

Broken or damaged wiring
Shock sensor malfunction
Problems with the airbag control module
Corrosion or oxidation of contacts

How to Fix

Diagnose the airbag system
Check the integrity of wiring and connectors
Test shock sensors
If necessary, replace the control module or other components
Reset the error and check the system

Related codes

B0001 B0002 B0003