2003 MGM LS Radio Data System (RDS)

I have the AM/FM Stereo/Cassette/Single CD. The owners manual says to press the RDS control until RDS ON or RDS OFF appears in the display. When I press the RDS control it goes from SELECT HOURS to SELECT MINS to blank, then it just repeats. I've tried it with the radio on, off.

I assume this means I don't have RDS, but why not? My radio looks exactly like the illustration in the owners manual, and everything else works exactly as the manual said.

Thanks!

No one answered me, so I'll answer myself. I had the radio on AM, so the RDS didn't work. I put in on FM and everything worked as described in the manual. It's pretty neat.