If your scan tool has displayed a B code, you’re dealing with a problem in your vehicle’s Body Control Systems rather than the engine or transmission. While P codes (Powertrain) receive most of the attention, Body (B) OBD-II diagnostic trouble codes are just as important because they affect the safety, comfort, convenience, and electronic systems modern vehicles rely on every day.

Body codes can indicate faults in the airbag system (SRS), seat belt pretensioners, occupant detection sensors, lighting systems, power windows, door locks, HVAC controls, body control modules (BCM), and dozens of other electronically controlled components.

Whether your Airbag Warning Light has illuminated or you’re troubleshooting a body electronics problem, this guide explains everything you need to know about B-series OBD-II codes, how they work, and where to find detailed repair information for each individual code.

What Are B Codes?

OBD-II diagnostic trouble codes are divided into four categories:

Prefix	System
P	Powertrain
B	Body
C	Chassis
U	Network & Communication

B Codes diagnose faults in electronic body systems including:

Supplemental Restraint System (SRS)
Airbags
Seat belt pretensioners
Occupant detection systems
Body Control Module (BCM)
Lighting
Power locks
Power windows
Climate control
Wipers
Mirrors
Security systems
Keyless entry
Driver assistance features

Unlike engine codes, many Body codes require a professional scan tool capable of communicating with manufacturer-specific modules.

Common Symptoms of a B Code

Symptoms vary depending on the affected system but may include:

Airbag Warning Light
Service Airbag message
ABS or stability warnings
Inoperative power windows
Door locks not functioning
Interior lighting issues
HVAC problems
Keyless entry failures
Security system faults
Passenger Airbag OFF indicator
Seat belt warning lights

Some Body codes affect convenience features, while others disable critical safety systems.

Are B Codes Serious?

Some are relatively minor.

Others are extremely serious.

For example:

Low Severity

Interior lighting faults
Power mirror problems
Door lock malfunctions

Moderate Severity

HVAC control issues
Body Control Module communication faults

High Severity

Airbag deployment circuits
Occupant detection systems
Crash sensors
Seat belt pretensioners

If your Airbag Warning Light is illuminated, the SRS may not deploy correctly during an accident.

Can You Drive With a B Code?

That depends on the affected system.

Generally:

✅ Window switch fault — Yes

✅ Power door lock issue — Yes

⚠️ Airbag fault — Not recommended

⚠️ Seat belt pretensioner fault — Repair immediately

⚠️ Crash sensor fault — Repair immediately

Never ignore any SRS-related B code.

How Are B Codes Diagnosed?

Proper diagnosis usually involves:

Reading Body codes with an advanced scan tool
Accessing manufacturer-specific subcodes
Reviewing live sensor data
Inspecting wiring and connectors
Testing Body Control Module inputs
Following factory service procedures

Many inexpensive code readers cannot access Body Control Modules.

Most Common B Code Categories

Airbag (SRS)

Driver airbag
Passenger airbag
Side airbags
Curtain airbags
Crash sensors
Seat occupancy sensors

Seat Belt Systems

Pretensioners
Buckle switches
Seat belt sensors

Occupant Detection

Passenger Presence System
Occupant Classification Module
Weight sensors

Lighting

Exterior lighting
Interior lighting
Adaptive headlights

BCM

Body Control Module communication
Module configuration
Electrical distribution

Comfort Systems

Power windows
Power seats
Mirrors
Sunroof
Climate control

Complete B Code Library

Below are the Body codes currently covered on Pro Street.

B0001–B0099

Code	Description
B0001	Driver Frontal Stage 1 Deployment Control
B0002	Driver Frontal Stage 1 Deployment Loop Open
B0004	Driver Frontal Stage 1 Deployment Loop Short
B0010	Passenger Frontal Airbag Circuit
B0012	Passenger Frontal Deployment Loop
B0020	Left Side Airbag Deployment Control
B0022	Left Side Airbag Deployment Loop Resistance
B0028	Right Side Airbag Deployment Loop Resistance
B0033	Driver Seat Belt Pretensioner Circuit
B0040	Left Front Impact Sensor Circuit
B0041	Left Front Impact Sensor Performance
B0045	Right Front Impact Sensor Performance
B0050	Driver Seat Belt Sensor Circuit
B0051	Passenger Seat Belt Sensor Circuit
B0052	Passenger Seat Belt Pretensioner Circuit
B0053	Driver Seat Belt Pretensioner Deployment Control
B0054	Passenger Pretensioner Deployment Loop
B0055	Passenger Pretensioner Resistance Low
B0056	Driver Pretensioner Deployment Loop Resistance
B0057	Driver Pretensioner Resistance Low
B0058	Passenger Pretensioner Resistance Low
B0059	Driver Pretensioner Resistance High
B0060	Passenger Pretensioner Resistance High
B0061	Driver Airbag Stage 1 Resistance High
B0062	Passenger Airbag Stage 1 Resistance High
B0063	Driver Airbag Stage 1 Open Circuit
B0064	Passenger Airbag Stage 1 Open Circuit
B0065	Driver Airbag Stage 2 Circuit
B0066	Passenger Airbag Stage 2 Circuit
B0067	Driver Airbag Stage 2 Resistance Low
B0068	Passenger Airbag Stage 2 Resistance Low
B0069	Driver Airbag Stage 2 Resistance High
B0070	Passenger Airbag Stage 2 Resistance High
B0071	Driver Airbag Stage 2 Open Circuit
B0072	Passenger Airbag Stage 2 Open Circuit
B0073	Driver Knee Airbag Circuit
B0074	Passenger Knee Airbag Circuit
B0075	Driver Knee Airbag Resistance Low
B0076	Passenger Knee Airbag Resistance Low
B0077	Driver Knee Airbag Resistance High
B0078	Passenger Knee Airbag Resistance High
B0079	Driver Knee Airbag Open Circuit
B0080	Passenger Knee Airbag Open Circuit
B0081	Driver Frontal Deployment Loop Stage 2
B0082	Passenger Frontal Deployment Loop Stage 2
B0083	Driver Frontal Deployment Loop Stage 2 Resistance Low
B0084	Passenger Frontal Deployment Loop Stage 2 Resistance Low
B0085	Driver Frontal Deployment Loop Stage 2 Resistance High
B0086	Passenger Frontal Deployment Loop Stage 2 Resistance High
B0087	Driver Frontal Deployment Loop Stage 2 Open Circuit
B0088	Driver Frontal Deployment Loop Stage 2 Performance
B0089	Left Side Airbag Resistance Low
B0090	Right Side Airbag Resistance Low
B0091	Left Side Airbag Resistance High
B0092	Right Side Airbag Resistance High
B0093	Left Side Airbag Open Circuit
B0094	Right Side Airbag Open Circuit
B0095	Right Frontal Restraints Sensor
B0096	Left Frontal Restraints Sensor
B0097	Right Frontal Restraints Sensor Performance
B0098	Left Frontal Restraints Sensor Performance
B0099	Passenger Presence System

New B-code guides are added regularly, with additional Body Control Module, lighting, HVAC, seat, and convenience system diagnostics planned.

Why B Codes Are Increasingly Common

Modern vehicles contain 50–100+ electronic control modules, each monitoring hundreds of sensors. As more safety and comfort features become computerized, Body codes have become significantly more common than they were just a decade ago.

Advanced systems such as:

Adaptive cruise control
Lane keeping assist
Blind spot monitoring
Automatic emergency braking
Occupant detection
Smart airbags

all rely on Body Control Modules and SRS components that can trigger B-series diagnostic trouble codes.

Final Thoughts

Body diagnostic trouble codes may not affect how your engine runs, but they often impact the systems that protect you and your passengers. From airbag deployment circuits and crash sensors to occupant classification systems and Body Control Modules, understanding B-series OBD-II codes is essential for proper diagnosis and safe vehicle operation.

Our growing library of detailed repair guides covers each code individually, including common causes, symptoms, diagnostic procedures, repair costs, and frequently asked questions to help you identify and fix the problem with confidence.

Bookmark this page and check back regularly as we continue expanding the most comprehensive B-code library available.

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B Code OBD-II Codes Explained: Complete Guide to Body Diagnostic Trouble Codes