The function of the car driver's airbag module
The function of the car driver's airbag module is to instantly pop out when the vehicle is in a collision, to cushion the impact between the driver's head and chest and the internal components of the vehicle, and to reduce the secondary collision injuries.
It belongs to a passive safety device and is an auxiliary to the seat belt. Only when both are used together can they effectively protect the driver.
Core function
Buffering impact: When a collision occurs, the airbag inflates and pops out, cushioning the body before it hits the steering wheel or dashboard, absorbing the impact force.
Preventing fatal injuries: It can especially prevent the steering wheel from hitting the driver's chest, causing severe trauma.
Reducing fatality rate: Data shows that in front-impact collisions of cars with airbags, the fatality rate of drivers significantly decreases (30% for large cars, 11% for midsize cars, and 14% for small cars).
Working process
Perceiving collision: Sensors monitor the vehicle's deceleration and the direction of the collision, and transmit the signals to the control module.
Judging and decision-making: The control module assesses the degree of the collision and decides whether to ignite and the amount of inflation.
Instant inflation: Trigger the gas generator, and the airbag expands in about 2 milliseconds.
Deflation and buffering: After the body comes into contact with the airbag, the airbag releases air through surface air holes, serving as a cushion, to reduce the impact.
The airbag expands very quickly (up to 150 to 250 miles per hour), and must fully expand before the impact to be effective in protecting; if it doesn't expand completely and hits, the effect will be greatly reduced.
Notes for Attention
Airbags are auxiliary devices and must be used in conjunction with seat belts; otherwise, their protective effect will be limited. In some vehicle models, airbags may not even deploy if seat belts are not fastened.
The driver's frontal airbag is installed in the center of the steering wheel, and the system container is usually labeled with "SRS" (Auxiliary Expandable Restraint System).
Airbags are one-time devices that need to be replaced after deployment. The modular design introduced since 2018 has reduced the replacement cost to some extent.
When the driver's safety airbag module malfunctions, the SRS warning light on the dashboard usually remains on, indicating that the airbag may not deploy normally during a collision. It is necessary to address this issue promptly. This is a matter related to the life-saving system and cannot be delayed.
Common causes
Poor contact of wiring or plugs: The most common issue, accounting for approximately 45% - 70%. This often occurs at the steering wheel's torsion bar or the yellow plug beneath the seat, and looseness, oxidation, or water ingress can all cause signal interruption.
Collision sensor failure: Moisture in the sensor, slight displacement after a minor collision, or aging can all cause false alarms, accounting for approximately 20%.
Airbag control unit (ECU) failure: Water ingress, unstable battery voltage, or post-collision residual effects can cause module damage, accounting for approximately 15%.
Airbag module aging or damage itself: This is more common in older vehicles over 10 years old. The gas generator may become wet and fail, accounting for approximately 10%.
Human modification impact: Modifying the steering wheel, adding seat covers, or applying films may come into contact with the airbag wiring, triggering the warning light.
How to handle it
First, try to power off and restart: Park in a safe place, turn off the engine, disconnect the negative terminal of the battery, wait for 5 to 10 minutes before reconnecting it, and then restart to see if the lights go out. If they go out, it is mostly due to a depleted battery or a random false alarm.
Check the plug under the seat: After powering off, check if the yellow airbag plug under the driver's or passenger's seat is loose. Reinsert it tightly and listen for a "click" sound.
Read the fault code to locate: If the lights are still on, use a diagnostic tool to read the fault code. Repair the component indicated by the code. Do not blindly replace the parts.
Find a professional institution for repair: If the lights are still on, when replacing components such as torsion springs, sensors, or control units, it is recommended to go to a 4S store or a qualified repair shop. After replacement, use a diagnostic tool to clear the fault code and match the system.
Before operating the airbag system, be sure to disconnect the negative terminal of the battery and wait for more than 5 minutes. Do not unplug the airbag plug while the power is on. Otherwise, it may accidentally detonate the airbag or damage the ECU. If the fault light is constantly on and you smell a burnt smell, immediately stop the vehicle and contact a tow truck. Do not continue driving.
If you want to know more, keep reading the other articles on this site!
Please call us if you need such products.
Zhuo Meng Shanghai Auto Co., Ltd. is committed to selling MG&MAXUS auto parts welcome to buy.
