I have the same problem...
I dont know what to try as there are no indications of an O/Speed control button.
Though the problem might have something to do with the steering wheel controller that was replaced to accommodate a new head unit.
You can turn off the seatbelt warning light in your 2006 Ford Explorer, by buckling the seatbelts. When the seat is occupied the warning light will stay on until the seatbelt is buckled.
buckle up
If the warning lights will not turn off it could be the on and off switch. It could also be the relay switch.
You can turn off the 2009 Toyota Camry seatbelt warning light by engaging the seatbelt. You can also remove the seatbelt warning light fuse. Removing the seatbelt warning light fuse is not recommended.
Put on the seat belt.
Get your engine checked
The ABS warning light can only be turned off with a specialized scan tool - or - fix the problem. See "Related Questions" below for more
Check owner's manual. If you don't have one copy and paste link below; www.fleet.ford.com/maintenance/owners_manuals
You probably need new rear disc bearings. Once you install the new bearings, the warning light should turn off.
take both battery cables off the battery then replace the light should go out but will come back if problem is not corrected
put it on
Open the passenger door and look at the end of the dash that it covers, if there is a key switch for the ignition key then yes you can! when you turn said keyswitch you should get a warning lamp illuminate on the dash when the car is running to remind you it is set to "off"