Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?

Are Lights the Only Thing the OBD Uses to Warn the Driver of Issues?

DashboardLights

If your car was manufactured after 1996, it has an OBD II system that monitors emissions and other systems on board. While it’s primarily focused on emissions, it can also report other problems that are only peripherally related to emissions (engine misfires, for instance). It communicates any potential problems to the driver through a single light in the dash – the Check Engine Light, also called the MIL or Malfunction Indicator Lamp.

Is the Check Engine Light the only connected light?

Yes. The only way your OBD system has to communicate with you is through the Check Engine Light. What’s more, the other lights in your dash are NOT connected to the OBD system (although advanced scan tools can access the car’s computer and read many of these trouble codes via the OBD II connector under the dash).

Common reasons the Check Engine Light is illuminated

If your Check Engine Light flashes on right after the engine cranks, and then turns off again, this is normal. This is the self-check procedure, and the OBD system letting you know that it’s operating.

If the Check Engine Light comes on and stays on, it means that the computer has identified a problem that has some sort of impact on emissions or engine control. These can range from engine misfires to failed oxygen sensors, dead catalytic converters and even a loose gas cap. You’ll need to have the code pulled by a mechanic to begin the diagnostic process and determine the cause of the problem.

If the Check Engine Light comes on and begins flashing, it means that your engine may be experiencing significant misfires, and that the catalytic converter could overheat as a result, causing a fire. You should immediately stop the car and have a mechanic diagnose and repair the problem.

While the OBD system can only use the Check Engine Light to communicate with you, it’s vital that you pay attention to that light and know what to do.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...

Related questions

Q: I recently replaced the starter and now my check engine light is on in my 1999 Nissan Maxima

Hello. The starter should not have anything to do with the check engine light. Since the check engine light is on I would scan the computer for codes. I am assuming that the engine has a serious misfire, which can...

Q: Q: Car cranks but won't turn over

Hello. This problem could be caused by several different things. You could be out of gas, the fuel pump might be working properly, the timing belt could be broken, there could be an issue with electricity getting to your spark...

Q: Car idling rough and missing.

A misfire will generally cause a rough idle, but you must find out if its one cylinder misfiring or a random misfire, this is were a scan tool is essential. If you can trace the misfire to one cylinder its...