Kitchen Aid Dishwasher won't start - has power

Hi,
I have a Kitchen Aid KUD01TJBS0 dishwasher that I think is 8 years old. It won’t start.
If I push the cancel/drain button I can hear the motor run. If I push start, nothing happens. All of the lights on the control panel work with the exception of two (Heavy and High Temp Scrub).
Thanks in advance!
Jennifer