Why is my "check engine" light on and what should I do?


Here's a *thrilling* action shot:
The quick video above shows the most common manifestation of a check engine light....
  • Check Engine yellow light is solid (middle left of cluster)
  • Vehicle Dynamics Control yellow light is solid (lower left)
  • Cruise Control green light is flashing (lower right)

If this is what you see, then you can temporarily drive your Subaru without damaging itThe solid check engine light indicates that your car requires attention but not immediately.

If the check engine light is flashing, your Subaru has a more severe problem and driving more than a few minutes might damage your valves, your catalytic converter, or other emission components.  It is rare for us to see a flashing check engine light, so it is unlikely that you will ever see one.  However, if you are driving and your check engine light starts to flash, take the next exit to a place where you can safely park the vehicle.  Call us or Subaru Roadside Assistance to have the vehicle towed.  

Why did these lights illuminate?

Your Subaru has a sophisticated on-board computer that monitors thousands of data points in the performance of the entire emissions system...from the fuel tank to the oxygen sensor.  Common problems that the system identifies:

  • Evaporative leaks.  The evaporation of unburned fuel is bad for the environment, so Subaru's system detects leaks.  Sometimes we tighten or replace a gas cap which fixes the problem. 
  • Misfires...when the combustion of fuel does not occur properly or at the right time.  Causes include valve misadjustment, faulty coils, old spark plugs, and bad wires.
  • Failing catalytic converter.  Catalytic converters reduce harmful emissions; as they age, they can lose efficiency.
  • Oil control valves sensing low oil.

Why are there other lights on?

To work properly, the cruise control system and vehicle dynamics control system require a powertrain operating at peak efficiency.  When the check engine light senses a problem, your Subaru deactivates those other systems to avoid erratic performance.

What will Planet Subaru do to fix the problem? 

One of our exhaustively trained technicians will connect your Subaru to a very expensive laptop.  Below are data downloaded from a Tribeca that was misfiring in cylinder #2.  Most independent repair shops have universal hand-held scanners that can generate a single code about the problem, but nothing like this!  Our technicians spend a lot of time in school updating their knowledge about how to interpret these data and effect the proper fix.  


How do I get my light extinguished?

Call us and we'll fix it, especially before your next state inspection since your car will fail the emissions test required by the stateSubaru's factory warranty covers many emissions related components as long as 15 years and 150,000 miles.  We'll let you know if you're covered.  Click here to get in touch.

"Third car from this Dealer and second from excellent salesperson. Service is also excellent and all cars purchased have been serviced there since they were bought." ~Frank S., North Weymouth, MA

Planet helps Subaru drivers in Boston, Cambridge, Brockton, and Plymouth.