We don't exactly know yet. From news reports from Japanese press, it appears to be adding a membrane or new seal to the door handle assembly to keep water from penetrating to the switch. I'll post the instructions as soon as they become available, but from looking at the instructions to remove the rear door outside handle assembly, it's likely going to be a pretty big job requiring the rear doors to be pretty well disassembled(removing the assembly is listed as step 24).
How about you read the yapper's thread where they show the fixed part? Safety Recall Rear Doors | PriusChat It's just below this one that you made. They even link a video showing exactly what goes on And like so many yappers have already said on this issue, it's not a big deal. Leave your auto lock in drive feature enabled and your doors will stay shut. Even if they somehow opened while driving, the force from the wind wouldn't allow them to just FLY open, they'd mostly stay close to the body of the car.
I missed that video in the other thread. Nice to finally know exactly what the fix is. So it looks like the article in the Japanese press about adding waterproofing layers was either mostly incorrect or just incorrectly translated. The fix isn't adding waterproofing layers, it's replacing a part(which is what I always figured they were going to have to do; so the news article back in June confused me). And it's as big of a job as I feared. You basically have to tear the rear door apart to get the assembly free(including removing the glass). The instructions say 1.0-1.5 hours, but I wonder if that's for both doors or just one? Probably both, but I'll wait to see the TSB document for confirmation. I wouldn't want to do the job myself. Doors can be a PITA to work on. (Says the guy that had to pull apart most of my front doors fairly recently to remove, modify, and replace the door wiring harnesses.)
Might anyone know the starting VIN of year 2024 Prius and Prius Prime in which the correction was made on new production? The retrofit is disturbing to me from a potential “rattle/vibration” stance.
Just picked up mine - it took them one-and-a-half hours. Couldn't spot any evidence of anything having being disturbed, so assuming they did anything, it was done very tidily.
FWIW, the European site shows the affected VINs (for plug-ins) as 03000156-03023857, from March 15, 2023 - March 29, 2024. Those numbers would correspond to US Prime VINs, but won't fully cover the range. It looks like they're just showing VINs that went to Europe, as I know 155 was a US car from a dealer allocation sheet I saw. And it won't help with non-plug-ins, as they've got a separate VIN sequence. Other reports say production was stopped in April 2024, and it affects all cars produced up to that point. Production restarted in June. So if your manufacturing date is after April 2024, you're good.