How do you reset the 'Maintenance Required' indicator on a 1992 Plymouth Voyager?

there's a test fixture you can either buy from the dealer, ugh, but if not you still have to go to the dealer and let them reset it. You might check with local repair shops that could do the resetting also. If it's the first time it has come on then you may need to have some routine maintenance done on it, in which case if you go to the dealer and have the maint. they will automatically reset it for you at not charge, otherwise they will charge you.