U0155 Smartkey ECU 2011 Prius 109k

Hi everyone,

I just bought a 2011 Toyota Prius at 109k. The day after I got the car (07/28), I got the U0155 code on both my bluedriver obd and the ancel obd that told me the U0155 came from my "SmartKey" ECU. My car drives perfectly and I haven't had any issues with starting the car or noticed any issues with the control panel. The high beam and/or light icon pops up when I turn on my lights or high beams. I haven't seen any warning lights. I just changed the smart key battery because the Prius was telling me the battery was low when I turned off the car but it didn't fix U0155 code.

Does anyone have any advice on what I should do? I read that I should not drive with this code? What is the range of the cost I can be looking at from best to worst case scenario?

I'm thinking of taking the car to the Toyota dealership to get it professionally diagnosed and possibly fixed but I am tight on cash because of the car purchase.

Thank you!