I took my 2021 Pilot to the dealer a few weeks ago because I was getting a weird combination of seemingly unrelated codes/errors including transmission, emissions, and blind spot error. Intermittently I couldn't put it in gear due to the error. The car had been left in auxiliary power a couple of days prior so I figured it might have caused a computer glitch or maybe the errors were from a drained battery. After checking the car, the dealership service tech messaged me that based on the codes, the transmission failed and replacement would be $8,000.00!!! I told them that made no sense since it was clearly drivable, had no previous transmission issues and only had 70,000 miles with up to date routine maintenance.
I took it elsewhere for a second opinion. After the second opinion mechanic drove it for 150 miles, he agreed with me that it was just a glitch from the auxiliary power drain. They completed the routine service, saved me over $7,000, and I've had no issues since.