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Will Disconnecting the Battery Reset the Airbag light?

Disconnecting the battery to reset the airbag light is not a guaranteed or permanent fix.

The light may still come back on if an underlying issue persists. It will also reset other things in the car, such as the clock and radio. You’ll have to adjust their settings again after reconnecting the battery. But you may find other electrical issues crop up as well. So, what’s the best way to reset the airbag light?

indicates airbag light on
Video | Mr Technic

First, check the SRS-ACM(Airbag Control Module), battery, airbag sensor, SRS wiring, seat belt tensioners, and clock spring. Only then try the battery disconnection method.

Resetting the airbag light by disconnecting the battery is a straightforward process. You turn off the ignition, disconnect the battery, and wait 15 minutes. Then, reconnect the battery and turn the ignition back on. It should be reset.

airbag control module diagram

If resetting the battery doesn’t work, you can use an OBD-II scanner to clear the fault code or manually remove the fuse for a while. If the issue persists, take your vehicle to an auto-electrician.

An Airbag Light Issue

The airbag light is part of the vehicle’s SRS (Supplemental Restraint System).

It serves as a warning indicator of a problem with the airbags. It should only illuminate momentarily when first starting the car. It should then turn off, but it indicates an issue if it remains on, flashes, or suddenly turns on while driving.

You shouldn’t ignore an airbag light issue.

The airbag should always be available for your safety in the event of a collision. You must, therefore, fix this issue right away.

Possible Causes

The airbag light usually comes on for any one or more of the following reasons:

  • A problem with the SRS-ACM (SRS’s Airbag Control Module). It has a small battery that powers the airbag system to ensure it can deploy the airbags in the event of a collision.
  • A problem with the airbag system’s sensor. The sensor is responsible for detecting a collision. If a collision occurs, it sends a signal to the ACM to instantly deploy the airbags. A malfunctioned sensor will be unable to perform this operation.
  • A problem with the airbag system’s wiring can also cause the airbag light to come on.
  • A malfunctioned SRS-ACM cannot receive the sensor’s signals to determine whether to deploy the airbags correctly. It might be due to an electrical or software issue, exposure to moisture, or physical damage.
  • Other causes – A problem with the seat belt tensioners or clock spring. The latter is a spiral cable that maintains the electrical connections between the steering wheel and the airbag system.

First Solutions to Try

So, before disconnecting the battery or trying one of the other alternative methods to reset an airbag light, make sure:

  • The SRS-ACM’s battery is not weak, as that might be the cause of the airbag light coming on. Replace it if it is.
  • The airbag sensor and SRS wiring are not physically damaged. Check them and have them replaced if they are.
  • The SRS-ACM is free of moisture and not physically damaged. Dry it, if necessary, or replace it if it’s damaged.
  • Have the seat belt tensioners and clock spring checked. Repair or replace them if damaged.

SRS Airbag Control Module
clock spring

Video | ChrisFix

It is relatively inexpensive if you need to replace the airbag’s sensor or wiring. But replacing a malfunctioned ACM would be more expensive.


Resetting an Airbag Light by Disconnecting the Battery

If the above solutions didn’t work, here are the steps to reset an airbag light by disconnecting the battery:

Step 1: Turn Ignition Off

Turn the ignition off and remove the key from it.

Step 2: Disconnect the Battery

Open the vehicle’s bonnet (or hood) and locate the battery.

Loosen the cable using a wrench or spanner. Detach the black wire from the battery’s negative terminal and the red wire from its positive terminal.

Step 3: Wait 15 Minutes

Wait for at least 15 minutes before reconnecting the battery.

Step 4: Reconnect the Battery

Reattach the black wire to the battery’s negative terminal and the red wire to its positive terminal.

Tighten the cable using a wrench or spanner.

Step 5: Turn Ignition On

Insert the key into the ignition and turn it on.

See if the airbag light turns off (after the momentary illumination) or remains on.

airbag lights turn off
Video | Mr Technic

Note that even if the airbag light turns off this time, it might come back on later. If so, you will need to investigate further, as there is likely to be an underlying issue you must resolve.

But there are two more methods you can also try to reset the airbag light:

  • Using an OBD-II scanner
  • Manual resetting


Alternative I: Using an OBD-II Scanner

The first alternative method requires using an OBD-II scanner.

An OBD-II scanner is a diagnostic tool that reads and clears the carputer’s fault codes. Here’s how to do that:

Step 1: Locate the OBD-II Port

Firstly, locate the OBD-II port on the car’s computer. The carputer is usually located under the dashboard on the driver’s side.

Step 2: Plug the OBD-II Scanner

Plug the OBD-II scanner into the OBD-II port.

Step 3: Turn the Ignition On

Turn the ignition on without starting the engine.

Step 4: Read and Clear the Codes

Read the airbag system-related fault codes by following the instructions on the OBD-II scanner’s display. Then, clear the codes.

The airbag light should turn off once the fault code is cleared. If it doesn’t, you can try turning it off manually.


Alternative II: Manual Resetting

If the fault code did not clear using the OBD-II scanner, or you don’t have one, you can manually reset the airbag light.

Step 1: Turn Ignition Off

Turn the ignition off and remove the key.

Step 2: Remove the Fuse

Locate the car’s fuse box. It is usually located under the dashboard on the driver’s side. Otherwise, it will probably be under the hood.

Open the fuse box and remove the fuse for the airbag system.

Step 3: Wait 15 Minutes

Wait approximately 10-15 minutes to allow the airbag system to discharge.

Step 4: Reinstall the Fuse

Reinstall the airbag fuse in the fuse box.

Step 5: Turn Ignition On

Now, turn the ignition back on and check the dashboard indicators for the airbag light.


FAQs

Is it okay to ignore the airbag light, at least for now?

As I said, the airbag is a part of your vehicle’s SRS.

It’s a warning indicator that something is wrong or has malfunctioned with the airbag system. Consequently, the airbags in your car will probably not work to protect you in the event of a collision.

So, seeing the airbag light on should be a serious safety concern. It puts you and your passengers at risk. Ignoring it could be a regretful decision.

Don’t ignore it.

Can a bad battery cause the airbag light to turn on?

The battery powers various electronics in your vehicle, including the airbag sensors.

A bad battery would be noticeable by its effects on other electrical devices in your car, including the headlights, radio, and navigation system. If you notice issues with any of them, they could very well be due to a bad battery.

Is it okay to ignore the airbag light, at least for now?
As I said, the airbag is a part of your vehicle’s SRS.

It’s a warning indicator that something is wrong or has malfunctioned with the airbag system. Consequently, the airbags in your car will probably not work to protect you in the event of a collision.

So, seeing the airbag light on should be a serious safety concern. It puts you and your passengers at risk. Ignoring it could be a regretful decision.

Don’t ignore it.

Can a bad battery cause the airbag light to turn on?

The battery powers various electronics in your vehicle, including the airbag sensors.

A bad battery would be noticeable by its effects on other electrical devices in your car, including the headlights, radio, and navigation system. If you notice issues with any of them, they could very well be due to a bad battery.

A bad battery would not affect the airbag sensors exclusively without affecting other electrical devices. But, it’s possible for a weak battery to cause some other electrical problem that leads to the airbag sensor malfunctioning.

If you’re sure the battery is bad, you should replace it anyway. See if it makes a difference to the airbag sensor and light.

What other precautions should I take to maintain my SRS?

Here are some more things to remember to prolong the life of your vehicle’s SRS and ensure it’s always in working order to protect you (Jex, 2007):

– Don’t subject the airbags to excessive temperatures (above 100°C).
– When removing an airbag, store it with the pad upwards to avoid inflation.
– Don’t allow any solvents or cleaning agents to touch the airbag assemblies. Only clean them using a damp cloth.
– Remove the airbag units before the use of arc-welding equipment on the vehicle.




References

Jex, R. M. VW Polo Petrol & Diesel Service & Repair Manual, 2002 to 2005. Haynes. 2007. https://www.google.com.pk/books/edition/VW_Polo_Petrol_Diesel_Service_Repair_Man/HoGpX5VcUNEC?hl=en&gbpv=0

Rob D. Thompson. Automotive Maintenance & Light Repair. Cengage Learning. 2023. https://www.google.com.pk/books/edition/Automotive_Maintenance_Light_Repair/1GCmEAAAQBAJ?hl=en&gbpv=0

SRS Airbag Control Module. https://www.myairbags.com/product/audi-s5-srs-airbag-control-module-reset-ecu/

Video References

ChrisFix

Mr Technic

The Home Depot

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About Alex Robertson

AvatarCertifications: B.M.E.
Education: University Of Denver - Mechanical Engineering
Lives In: Denver Colorado

Hi, I’m Alex! I’m a co-founder, content strategist, and writer and a close friend of our co-owner, Sam Orlovsky. I received my Bachelor of Mechanical Engineering (B.M.E.) degree from Denver, where we studied together. My passion for technical and creative writing has led me to help Sam with this project.

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