Just wanted to update, in case anyone else requires help.
After gaining access to the PCB board, I replaced one of the burnt out relays. This repaired the fault I was having. The dishwasher would get stuck with one minute remaining and wouldn’t complete the washing programme.
The whole repair was reasonably easy and didn’t take too long to do, about an hour.
The relay cost me £2.50, and saved me forking out for a £150 PCB unit, or a £500 new dishwasher.