A sensor could be bad. Take it to Auto Zone and have them run a diagnostic. It's free and they usually have the parts on hand.
service engion soon light is on
That is one of many possible causes.
well it needs to be serviced...soon
The service engine light is the same thing as a check engine light.
The service engine soon light comes on when the engine computer has detected a malfunction and set a code. You need to have the system checked for codes to know possible causes.
There are pages and pages and items that can cause a check engine light. You need to have it checked for codes with a scan tool.
Get the computer scanned to see what the problem is.
the computer tells it to glow.
There are many causes for a service engine light. You need to have it checked for codes. Then you can diagnose from there.
The service engine soon light comes on when the computer detects a malfunction and sets a code. see related questions below for more info.
The problem was not fixed with a tune up, or the light is on because it was not reset by the service station.
The service engine soon light comes on when there is a problem with the engine or transmission. They are both monitored and controlled by a computer. You will need to take the car to a shop or AutoZone can read the codes for free. This will at least tell you what area is setting the light.