This is just crazy. Unless the part numbers have revisions, replacing parts with existing designs will not solve the problem. The root cause is back-EMF. The resolution is a flyback diode as discussed in previous posts of this thread. Unless Honda R&D put in a diode into the schematic, wiring diagram, and ultimately the harness, this problem will persist.Purchased a new 2019 Pilot Touring in November 2018 and the snap crackle popping sound started between 6,000 and 7,000 miles. And now started losing LCD intermittently. Sound has occurred a couple times with doors locking. I am being told this is probably a MOST Bus issue and a Service News Article (same thing as TSB?) was issued in March 2019 for 2019 Pilots, 2018-19 Odyssey's and 2019 Passports. Since it only applies to 2019 Pilots I wonder if this is a new issue unrelated to the problems with AC. We've only owned the vehicle for the winter months so we haven't even turned the AC on yet.
After connections checked and were fine I am told the next step is to replace the Tuner unit, Stereo Amplifier, Blue Ray Player and Two Wiring Harnesses.
I'll let you know how I make out after the parts are replaced.
I was replacing relays -- on my dime -- at $16/pop twice per year until I wired in the solution myself.