The light came on while I was driving,it stay on all the time, what malfunction could it be?

Service Engine Soon

If the Service Engine Soon indicator light stays lit after you've started the engine, the On Board Diagnostics system (OBD) has detected a malfunction of the vehicle emissions control system. Contact your authorized dealer as soon as possible.
If indicator light is blinking, an engine misfire may be occurring, which could damage your catalytic converter. Drive in a moderate fashion (avoid heavy acceleration and deceleration), and have your vehicle serviced immediately.*
The Service Engine Soon indicator light illuminates when the ignition is first turned on (prior to engine start) in order to test the bulb, as well as indicate whether the vehicle is ready for Inspection/Maintenance (I/M) testing.
Normally, the Service Engine Soon light will stay on until the engine is cranked, then turn itself off if no malfunctions are present. However, if after 15 seconds this light blinks eight times, it means that the vehicle is not ready for I/M testing.Check this link out Gary.
https://owner.ford.com/how-tos/vehicle-features/dashboard-instrument-cluster/warning-lamps-and-indicators.html

Yes, the car can be driven but it is advised to check in a timely fashion the reason for the MIL to have come on.

Same as the last time you got a MIL lamp on any vehicle

Check for codes,look them up & diagnose the system that
set the codes & then component test

You need an OBD2 reader to pick up your fault codes.

that code is for a MIL indicator malfunction-in other words, your check engine light is malfunctioning...do you have a MIL light that works when you turn you key on, before starting? If not, the bulb is blown out, and you should replace it. If it does work, I'd suggest disconnecting the negative battery cable and letting the car sit for 5 minutes, then start it up and let it idle (no gas at all) for 5 minutes, then drive it lightly for another 5-if the light stays on, you have a malfunction with either the wiring to the light or possibly the ECM.

Driving a vehicle,unaware of the purpose
of any light, you get on the dash, is hard for
me to fathom

Those type of lights have been on vehicles
for 30 years

Your vehicle doesn't operate correctly

You ignore dash lights,why?

You have system malfunctions

Common sense. It doesn't work well
and you need to find out why.

If you continue to drive a vehicle, and don't
educate yourself,it will over time get expensive

Some check lights mean to stop using it
until repaired

It has 2 functions.

1. to let you know that your Traction and Stability Control System is active. This means that your tires are slipping or your car is leaning and the ststem is actively taking corrective action. This should only cause the light to come on for a few seconds at a time.

2. To let you know that the Traction and Stability Control System is disabled. It may be because the button has been pushed to turn it off or it may be due to a malfunction in the system. Thjis will cause the light to come on and stay on. If it is staying on and it is not because you have turned it off, then the system will have to be diagnosed to find out what the malfunction is that has caused it.

Abs Light:
If its glowing momentarily while driving in slick conditions then its normal operation..
But if it stays glowing even under dry pavement then there is a problem with your anti lock brake and traction control system..
It happens commonly of wheel speed sensor which malfunctions..
Try to access the data in the anti lock brake module to find out which one malfunctions..

Could be exhaust problem, Maybe the catalytic converter. Ask a shop to check the computer.
if it is a converter you can buy on line cheaper than the dealer. be sure to ask a shop if they will put on your part.
Good luck

I had the samething happen to my Jetta. I took it to the dealer and nothing was wrong.
I would think it's safe to drive until Monday when the VW shop opens.
My 2 cents