Airbag Module – Function, Components, Symptoms, Diagnosis, and Possible DTCs

The Airbag Module is a complete airbag assembly designed to protect vehicle occupants during a collision. Each module contains a folded airbag cushion, an inflator, and an electrical igniter. When the Airbag Control Module (ACM/RCM/SDM/ORC) detects a severe impact, it sends an electrical signal that deploys the airbag within milliseconds.

What Is an Airbag Module?

Airbag Module = Airbag Cushion + Inflator + Housing + Electrical Connector

Main Functions

• Protects occupants during a collision.
• Reduces the risk of head and chest injuries.
• Works together with seat belts and pretensioners.
• Deploys only when commanded by the SRS control module.

Common Types of Airbag Modules

• Driver Airbag (DAB)
• Passenger Airbag (PAB)
• Side Airbag (SAB)
• Curtain Airbag (CAB)
• Knee Airbag (KAB)
• Center Airbag (on some vehicles)

Simple System Diagram

 Impact Sensors
       │
       ▼
+----------------------+
| Airbag Control Module|
+----------------------+
       │ Deploy Signal
       ▼
+----------------------+
|    Airbag Module     |
+----------------------+
       │
       ▼
 Airbag Inflates

Common Symptoms of a Fault

• Airbag warning light ON.
• Stored SRS diagnostic trouble codes.
• Open or short circuit faults.
• High or low resistance in the deployment circuit.
• Previous deployment requiring replacement.

Possible Diagnostic Trouble Codes (DTCs)

• B0010–B0015 – Driver Airbag Circuit
• B0020–B0028 – Passenger Airbag Circuit
• B0051–B0053 – Deployment Loop Faults
• B1000 – SRS Control Module Internal Fault
• Manufacturer-specific deployment circuit DTCs

Diagnosis Tips

• Read SRS codes using a professional scan tool.
• Inspect connectors and wiring without applying external voltage.
• Check for damaged clockspring (driver airbag).
• Replace any deployed airbag module.
• Follow the manufacturer's safety procedures before servicing.

Important Safety Note

Airbag modules contain pyrotechnic inflators and can deploy with great force. Always disconnect the battery and wait the specified time before servicing the SRS system. Never measure airbag resistance directly with a standard multimeter unless the manufacturer specifically permits the procedure.

Frequently Asked Questions

Can an airbag module be reused after deployment?

No. A deployed airbag module must always be replaced.

Can a faulty airbag module turn on the SRS warning light?

Yes. Open circuits, short circuits, or abnormal resistance can illuminate the airbag warning indicator.

Does every vehicle have the same number of airbag modules?

No. The number and type of airbag modules vary depending on the vehicle model and equipment level.