We're on our 2nd dishwasher in 4.5 years so I've given up expecting things to last. Maybe yours has decided to take early retirement. No harm to Google it anyway but we found it was more cost effective to replace it then to pay for a service call and parts.
As Gebbel says you will need to get someone (qualified/knowledgeble) to look at it.
It could be any of a number of things, eg, water level sensor/thermostat/heating element/wiring etc....
Or it could be as simple as a bad connection, lets hope....
Sorry could'nt be of more help.