"ER" code on Frigidaire dishwasher display

Hi, I have a Frigidaire dishwasher(model#: PLD3460RDC0) that is displaying "ER" on the display and a bunch of other buttons are blinking but don’t respond when pushed. I did some looking around and among other things I found these instructions which I followed:

"With the ER fault code on the display, remove the top membrane ribbon from the control and then press the Start/Cancel pad. In 5 to 10 seconds, the ER code should clear and the display should be blank at this time. Press the Start/Cancel pad once more, this will restart the previously selected cycle. If the ER code does not clear or the unit does not start, replace the front membrane switch."

So once I removed the top membrane’s ribbon etc. the ER code did clear and the previous cycle started. My front membrane must be ok then right? Would you conclude that it is most likely the top membrane that needs to be replaced? This is all new to me so I was hoping for a second opinion as I’m not real confident and don’t want to purchase parts that I don’t even need. Other places referred to the top button array as the "top membrane." On your website would the "switch assembly"(part #: AP3778734) be the part I’m looking for?

Like I said this is new to me so I hope all that made sense. Anyway I’d be grateful if someone could help me out. Any suggestions or advice would be much appreciated. Thanks.

Jason