"ICS Malfunction See Dealer" fixed after grille replacement

My 2017 Prime was backed into causing minor damage to the grille (part number: 53101-47052). I replaced the grille and the car immediately started complaining "ICS Malfunction See Dealer" and the clearance sensor stopped working.

Since I had the old bumper with the original ICS senor (part number: 89341-48040) I replaced the new sensors with the old sensors because I thought maybe the devices were serialized.

Sure enough, reconnecting the old sensors back and driving above 22mph the error went away and now the ICS system is working properly.

So, if you still have the old sensors that were working and you don't want to take it to Toyota to get it re-calibrated (dealer quoted $600) try reconnecting old sensors. You might get lucky like me.