2 Signs of a Bad Airbag Control Module (& Replacement Cost)

The airbag control module controls the airbag sensors and all other airbag functions. Here's how to tell your airbag control module is bad and how much it costs to replace it.

airbag sign

In modern vehicles, airbags are designed to keep you and your occupants safe. However, these systems are made up of several parts that must be working together to operate properly. If you have a bad airbag control module, the airbag might not protect you as it was designed to.

We look at the symptoms that something is wrong with your airbag control module, discuss how to replace it and examine the costs. Let’s begin with a quick look at the signs to look for:

The most common symptom of a bad airbag control module is an SRS warning light on your dashboard, and probably the only sign you will notice. The other symptom is that the airbags won’t deploy in an accident and that’s something you definitely do not want to happen.

Here’s more detailed information about the different symptoms of a bad airbag control module:

Bad Airbag Control Unit Symptoms

1. SRS Warning Lights

airbag light

The airbag control module is part of the Supplemental Restraint System in your vehicle. If there is a problem with this vital part, the SRS warning light will come on to alert you. 

However, this warning light can mean any number of things. It could also be that the sensor is bad, there’s a malfunctioning clock spring or the seat belt pretensioner isn’t operating correctly. If you have an OBDII scanner with SRS capability, you should be able to pinpoint the problem easily. 

2. Airbags Don’t Deploy

small car crash

Whenever there is a fault with the airbag system, you put yourself at risk if an accident should occur. While the SRS light might illuminate, there’s always the chance that there’s a malfunction and you might receive no alert.

In this case, the only way you would know that something is wrong with the airbag system is when they don’t deploy during an accident. No one wants to find out this way, which is why it’s critical to check any trouble codes when they occur. 

Airbag Control Module Location

Once you figure out what’s wrong with this vital part, you want to know where the airbag control module is located. Unfortunately, it’s in a different location in every vehicle. It could be found near the front fascia, engine, front bumper or passenger seat area.

The best way to find the airbag control module location is to look in your owner’s manual. Once you replace it, you might need your OBDII scanner to reset the trouble codes. 

The Function of an Airbag Control Module

airbag control unit

All modern vehicles contain an airbag control module to operate the vital safety system. Seat belts provide the first line of defense when an accident occurs, but the airbags are considered supplemental to be used with the seat belts.

The Supplemental Restraint System (SRS) or airbag system has been installed in any vehicle manufactured after 1998. To work correctly, the system relies on numerous sensors coming from both airbags and the airbag clock spring, which is attached to the driver’s side airbag and steering column. The system also receives information from the seat belts and any other airbags that might be in the vehicle, such as the roof-mounted curtain airbags or knee airbags. 

All of this information is sent through the airbag control module. Other names for this part include the airbag electronic control unit or SRS control module. Basically, this part is the brain of the system, coordinating all of the SRS components for a seamless operation.

The airbag control module is monitoring all of the data sent from the various sensors. It uses this information to evaluate when a crash occurs. When the airbags are needed, the module triggers the Supplemental Restraint System parts, including the appropriate airbags, to ensure the severity of the accident is lessened on occupants. 

The airbag control module also determines if the airbags should remain intact during an incident. Inside the airbag control module data is stored that is calculated during an event. This information includes seatbelt usage, brake use, throttle position and vehicle speed. This information can later be downloaded by a technician to evaluate what happened during an accident. 

Airbag Control Module Replacement Cost

The average airbag control module replacement cost is typically between $600 and $700. The labor will cost around $90 to $120, while the parts are usually priced around $510.

Most people will never need to replace the airbag control module because this part is designed to last the lifetime of the vehicle. 

However, you should never continue driving once the SRS warning light comes on. If the airbag control module is faulty, you are putting yourself and your occupants at risk during a crash. The Supplemental Restraint System is not going to operate properly with a faulty airbag control module.

If you have an OBDII scanner with SRS reading ability, you should be able to diagnose the system yourself. Additionally, you might be able to replace the airbag control module with some basic tools and know-how, thereby saving you more money on the labor costs. Once the replacement of the airbag control module is complete, you may also need your diagnostic tool to reset the codes and turn the SRS warning light off.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.