The airbag warning light which is illuminating in your Nissan Altima can be concerning.
It signals that there could be a problem with one or more of the supplementary restraint system (SRS) components.
So, let’s find out the reasons for this issue.
Table of Contents
Common Reasons for the Airbag Light Illumination and How to Investigate the Issue
Faulty Airbag Control Module
- The airbag control module is the main computer that monitors all airbag components and triggers airbag deployment during a collision.
- If it detects a problem with the system, it will turn on the airbag light.
- Issues with the module itself due to a faulty circuit or crash damage that corrupted its programming could cause constant warning light illumination.
- A mechanic can access stored trouble codes in the module that may point to specifics about internal failures.
- In many cases, the entire airbag control module requires replacement to restore the normal function.
Disconnected or Damaged Airbag Wiring
- There is an intricate network of wiring that connects the airbag control module to crash sensors, seat occupancy detectors, and airbag modules that are located throughout the vehicle.
- If the wiring is damaged, disconnected, or showing high resistance due to corrosion, communication errors generate a warning light.
- A mechanic should inspect wiring integrity, look for rubbing or chafing damage, and test circuits for proper voltage and resistance patterns.
- Any compromised wiring must be repaired or replaced as well.
Defective Crash Sensors
- Crash sensors mounted at the front of the vehicle supply key data to the airbag module can be out of function after a collision.
- If they become damaged or inoperable, the module can’t fully determine any crash dynamics.
- So, as a result, it will send a diagnostic trouble code that triggers the warning light.
- Most commonly, front-mounted accelerometers go bad over time due to their exposure to weather and road hazards.
- A trained technician can determine if any of the crash sensors are malfunctioning through computer diagnostics.
Seatbelt Tensioners and Buckles Issues
- Problems with seatbelt tensioners and buckles also activate the airbag warning light since seatbelts have integrated occupancy detection and pretensioning.
- Fault codes helps to identify that which component needs attention.
- For tensioners, replacement of the entire seatbelt assembly may be required. Buckles usually need cleaning or straightforward repairs.
Passenger Seat Occupancy Sensor Problems
- The passenger seat has a sophisticated occupancy sensor system to determine if the seat contains a person that requires airbag protection.
- Issues with wiring, calibration, or the mat sensor itself can cause the whole system to malfunction and trigger the error codes.
- Advanced scan tools can show the specific sensor faults stored by the airbag computer and guide to some troubleshooting steps.
Getting to the Root Cause of Intermittent Airbag Light Issues
- Take note of any patterns, like specific road conditions, that cause the light to turn on. This can help to recreate the issues during the diagnosis.
- Have the airbag control module scanned at both times while the light is on and while it is off. Comparing the code differences can reveal clues.
- Perform a visual inspection of the wiring harnesses that are related to components flagged in codes during the light activation. Look for chafed or melted areas that may be shorting intermittently.
- Use a high-precision ohmmeter to test the wiring resistance values. Any spikes likely indicate a breach in a wire’s insulation that makes contact randomly due to vibration.
FAQs About Nissan Altima Airbag Light Stays On
Q: Can I keep driving my Altima if the airbag light is on?
A: You should not drive for an extended time with the airbag light onboard. It likely means that the critical supplemental restraint components are not going to be operational in a crash when needed for safety.