Hi. Have you had a dead battery, or had the battery disconnected recently?
Lets also check for codes. Cycle the key from off to on three times ending with it on and watch the digital odometer display. The codes have a p and four numbers, there may be more than one code. Write down any that you see and post them here and I'll tell you what to do.
Was the car running alright other than this? Did this come on suddenly or was it gradual?