Rear seat belt warning randomly going off on 3IS
In the last month I'm having an extremely annoying issue with my 2017 IS: the rear seat belt warning randomly starts beeping while driving, with only myself being in the car and without objects on the rear cushion. At first I solved it by having the central belt buckled all the time, but yesterday it started beeping after 40 minutes of driving and it won't stop even if I buckled all the 3 belts. I had to shut off and on again the car to make it stop.
I well know that the IS doesn't have a rear seat occupancy sensor and the whole rear seatbelt system only works with the Toyota Door Logic that checks if one of the rear doors has been opened before driving, but I'm never touching the rear doors and still it's giving me attitude.
The car it's still under the 10 years extended warranty so I'll have it checked at the next service, but I'm wondering if anyone of you has ever had this problem before?
I'm struggling to find any solution online because everybody having this problem with Toyota vehicles is having it just because they're opening the rear doors to put bags/object in the rear, triggering the belt warning system, but that's not my case.