99 Concorde Speedometer stopped working

How do I check the codes on a 99 Concorde LXi?

My speedometer stopped working the other day, then the Distance to Empty went from 40 miles to 5 miles, then back to 40 miles, then it stalled.

Started back up but it stalled.

Also before this the back passenger window would not roll down. (Power windows).

Please help. ...

Check codes: keyON, keyOFF, keyON, keyOFF, keyON [in 5 seconds] ... the ODOmeter will display any codes (if any) followed by "done" -- if there are no codes, the ODO will appear. My 99 lxi works this way.