If this is a 1989 Cadillac Deville your Dash should look like this & the Button should be on the left as indicated
I have attached a reset proceedure for you. This seems to be a problem, and my tech info had a note in it from a technician from another shop. It seems to be the fix.
I attached the info below, with the whole discussion.
WE FIXED THIS PROBLEM BY LOWERING THE LOWER DASH PANEL AND UNPLUGGING THE GRAY CONNECTOR ON THE RIGHT SIDE OF STEERING COLUMN. WHEN IT IS PLUGGED IN IT IS ON METRIC AND UNPLUGGED IS ENGLISH.