The airbag warning light in a Ford Mondeo may illuminate when the airbag is malfunctioning. After you have had the airbag assembly looked at by a mechanic and fixed, you need to reset the airbag or SRS warning light on your Mondeo. You need to purchas a diagnostic reset tool from your dealership or any auto parts store to do this job.
Locate and open the fuse panel which can be found underneath the steering column on the dashboard. Pull down on it from the top with your fingers.
Plug the connector end of the diagnostic reset tool into the pinned receiver port on the fuse panel.
Put the key into the ignition and turn it to the "II" position. Wait for the diagnostic reset tool to stop blinking. This means the SRS light has been reset.
Unplug the diagnostic reset tool and turn off the vehicle.
Turn the engine on and verify that the SRS light has shut off of the instrument panel.
Ask your local auto parts dealer if you can borrow their reset tool for free. Most off this as a service to their customers.