What Does "Service Engine Soon" mean on Nissan Altima?

If you drive a new car, you want to know it'll stay in great shape. Monitoring the health of your vehicle is one way to ensure that happens. That's where the service engine light comes in. This light indicates that your vehicle needs service.

However, this indicator has different meanings for each car maker. Nissan's "service engine soon" light stands for "check engine," meaning there could be something wrong with your car's engine management system. That said, not all service engine lights are created equal.


The "Service Engine Soon" light on your Nissan Altima indicates that the vehicle's onboard diagnostics system has detected a problem. When this light comes on, the vehicle must be taken to a Nissan dealership or certified repair facility for service. This issue will need to be diagnosed and repaired to clear the light and keep the vehicle running properly.

Quick Fixes

  • The "Service Engine Soon" light indicates an issue with the vehicle's emission control system.
  • The light may come on due to a problem with the catalytic converter, oxygen sensor, or EVAP system.
  • The light is intended to alert the driver to the problem so that it can be fixed, usually by a mechanic.

What Does The Service Engine Soon Light Mean On A Nissan?

Service Engine Soon Light : Explained and How to Fix (Answer)

The "service engine soon" or "check engine" light on a Nissan alerts you to potential problems with the emissions system. That said, the light can also mean the lambda sensor isn't working properly and may cause the car to shift into a limp mode or disable the car's engine entirely.

This is why it is important to address the issue as soon as possible. A car that's out of emissions compliance is potentially very costly to drive. If you're not sure what the check engine light means, here are some common causes:

  • There's a problem with the ignition timing; this could be a problem with the timing belt or the ignition control module.
  • There's an issue with the fuel system: a restricted fuel filter, a clogged fuel injector, or low fuel pressure.
  • There's a problem with the oxygen sensor, possibly due to a clogged sensor or a loose or worn wiring connection. The engine will run too rich if a sensor fails. This can cause the MIL to come on.
  • Incorrect fuel injection timing - If the timing of the fuel injection is off, this can cause the engine to run rich or lean. This can cause the MIL (malfunction indicator light) to come on.
  • Air intake sensor issues - An air intake sensor that fails to detect the proper amount of air entering the engine will cause the engine to run lean. This can trigger the MIL.

Why Is The Service Engine Soon Light Coming On?

As we mentioned, the "service engine soon" light indicates a problem with your car's emissions system. It comes on when one or more emissions sensors detect a fault.
When the check engine light comes on, you should take your car to the nearest repair shop. You can't simply reset the light like you can with some other systems. This is because resetting the service engine light may put you and other drivers at risk.

The problem(s) indicated by the service engine soon light needs to be fixed right away. You also run the risk of damaging your engine.

How To Reset The Service Engine Soon Light On A Nissan?

While you can't reset a Nissan check engine light, you can follow the troubleshooting process to determine what's causing the light to come on. The first thing to do is check your maintenance schedule to see if your car needs an emissions-related check. If so, get the issue addressed as soon as possible. Next, check the following emissions-related components:

  • Exhaust gas recirculation (EGR) valve - This valve routes a specified portion of the combustion gasses back into the intake manifold. It's meant to control the air/fuel ratio. An EGR valve malfunction can trigger the check engine light.
  • Fuel injectors - These send fuel into the combustion chambers, where it mixes with air. An issue with one or more fuel injectors can trigger the check engine light.
  • Airflow sensor - This measures the amount of air entering the engine and adjusts the fuel injection rate accordingly. An airflow sensor malfunction can trigger the check engine light.
  • Oxygen sensor - This measures the amount of oxygen in the exhaust. It's used to determine if the fuel in the cylinders should be enriched. An oxygen sensor issue can trigger the check engine light.


Seeing the "service engine soon" light on your new Nissan Altima is never good. That said, it's better to know more about the issue now than later. We recommend following the troubleshooting process to identify the cause of the light. If you don't find anything wrong, we recommend taking your Altima to a mechanic. The sooner you address the issue, the less it will cost to fix it.