Airbag Modules (ECUs)
Airbag Modules & ECUs – Vehicle Safety Explained
What Is an Airbag Control Module?
An Airbag Control Module (ACM) — also known as an Airbag ECU, SRS ECU, or Crash Sensor Module — is a critical component of a vehicle’s Supplemental Restraint System (SRS). This electronic unit is responsible for detecting impacts and deploying airbags and seatbelt pretensioners during a collision.
Common Names:
- Airbag ECU
- SRS Control Unit
- Crash Sensor Module
- Restraint Control Module (RCM)
Repair Enquiry Form
How It Works: Monitoring, Analysis & Deployment
- Constant Monitoring
The airbag ECU constantly monitors various sensors and circuits in the vehicle, including:
- Crash impact sensors
- Seatbelt tensioners
- Occupancy sensors
- Airbag wiring harnesses
If a fault is detected — such as abnormal resistance or a disconnected airbag — the system will trigger a warning light on the dashboard.
- Crash Detection
When a crash occurs, the module receives input from:
- Front, side, and rear impact sensors
- Seatbelt buckle switches
- Occupant classification systems
- Accelerometers and gyroscopes
- Wheel speed sensors (via ABS/ESP modules)
- Vehicle ignition and power status
Using these inputs, the ECU calculates the severity and type of collision in milliseconds and decides whether to deploy airbags, seatbelt pretensioners, or other safety mechanisms.
- Post-Crash Functions
In modern systems, the module may also:
- Unlock doors
- Cut fuel supply
- Activate hazard lights
- Store crash data (Event Data Recording)
Where Is the Airbag ECU Located?
Typically, the airbag module is located in a central, protected area within the vehicle cabin:
- Under the centre console
- Beneath the dashboard
- Near the gear lever or handbrake
It is a sealed unit that includes integrated hardware and software designed to withstand extreme conditions.
Faults, Airbag Light & Reset Services
Why Does the Airbag Light Turn On?
The airbag warning light may illuminate for reasons such as:
- Disconnected or faulty airbag sensors
- Previous collision data stored in the ECU
- Faulty seatbelt pretensioners
- Battery or voltage-related issues
- Corrupted firmware or data
Reset vs Replacement
After a crash or fault, the airbag ECU may lock itself and store “crash data” or diagnostic trouble codes (DTCs). In many cases, these modules can be:
- Reset: Crash data and faults are erased, and the module is returned to its pre-crash state.
- Repaired: Internal components are restored or replaced if damaged.
This process allows safe reuse of the module without the need for full replacement, saving time and maintaining original manufacturer calibration.
Why Choose Professional ECU Services?
- OEM-Level Diagnostics: Full fault code identification and clearing
- Fast Turnaround: Efficient reset and repair with minimal vehicle downtime
- Plug & Play: Reset modules can often be reinstalled without reprogramming
- Reliable & Safe: Only quality-tested parts and protocols used
Expert Airbag ECU Services
Whether you’re dealing with an SRS warning light, crash data, or ECU failure, our professional airbag module reset and repair services are designed to restore your vehicle’s safety system to full working order.
Contact us today to:
- Diagnose and reset your Airbag ECU
- Clear crash data and warning lights
- Avoid costly replacements
- Ensure road safety and compliance
