My Volvo Check Engine or Service Light is On. What Do I Do?
Don't Panic! But also do not ignore it!
Your Volvo is trying to tell you something. Heed the warning and you will see many miles and years of
continued service from your Volvo.
It's a little rectangle that you almost do not notice when it flashes briefly as you start your Volvo.
That flash tells you the computer is ready to monitor all the various sensors that it checks.
Usually that is the only time you see it.
But then one day, there it is glowing yellow and warning you to "Check Engine" or "Service Engine Soon".
What does it mean? What do you check and why?
All cars, pickups and SUV's sold in the US are required to meet the standards set by the Environmental
Protection Agency (EPA). They are required to have a computerized diagnostic system to regulate and
monitor the emission control system. If a problem develops, the warning light is lit up to warn the driver
that there is a problem and some service is required to correct the problem.
Why is the Light Flashing?
This indicates a more important problem exists and the vehicle should not be driven much further before
the problem is diagnosed and corrected. For instance the catalytic converter may be overheating.
What if the Light is Steady?
This indicates a less immediate and less serious problem. There are literally hundreds of conditions being
monitored by the vehicle's computer. Any one or these may vary enough from the normal range to cause
the light to be turned on. It is best not to drive too many days before finding and fixing the cause.
What if the Light goes Off by Itself?
If the light does go off, it does not mean the computer has a malfunction. There can be a very good reason.
Believe it or not, a common cause is a loose gas cap! How can that be?
The fuel system pressure is also monitored and a loose gas cap will cause a low pressure condition that can
be interpreted by the computer as a problem. If that was the cause, the dash light will usually go off in a day
or two after the cap is tightened. Remember to always tighten the cap until it just clicks.
The dash light may also go off in a few days if there was any other temporary condition that has cleared up.
Perhaps there was a plug that was fouled due to frequent short trips not allowing the engine to come to
proper operating temperature. It can be cleared because you drove longer at the operating temperature
and the carbon deposits were burned away.
What if the Light Stays On?
If the light stays on, you need to have the problem diagnosed and fixed or you may damage expensive
engine or exhaust components.
What if a Warning Light is RED?
A RED indicator light means the problem is immediate and severe. Pull over, turn off the ignition and
determine the cause or call a tow vehicle. This can be caused by the engine overheating, low oil pressure,
brake failure or other severe problems. Be careful as you pull over in case the problem is safety related.
Do not wait! Permanent engine failure may only be seconds away.