Passenger Light Seat Belt GHOST?!

You need one of those ghost detectors.

 

If there's not a ghost detector store near you, you might look into the Repair Manual (more info) regarding recalibration of the Occupant Classification System.

 

Out of warranty? Even if not, maybe best not to darken their doorstep lol: they'll be telling you a fuel system cleaning will fix it.

 

It's not out of the question that somebody who has access to the OCS troubleshooting/recalibration instructions might post them. Stuff like that happens sometimes.

 

What, his passenger seat *is* a ghost detector!

He needs to know about the weight sensor that is malfunctioning in the seat bottom. Are they hard to change out?

 

There are four of them. Occupant Classification Systems are not your grandpa's car's butt-in-the-seat sensor to trigger the seat belt buzzer. Because of the multiple weight sensors, they can detect weight and weight distribution in the seat and select air bag deployment forces appropriate for man, woman, or child of such-and-such size.

And the steps in the repair manual for recalibrating would make sense to follow before changing anything out.

 

Indeed. The calibration is done using a Toyota Techstream diagnostic system, under Body Electrical > Occupant Detection > Utility > Zero Point Calibration. The car has to be parked on a level surface, with nothing on or touching the passenger seat, and the seat in its rearmost and least reclined position, with the headrest at its lowest position.

If that doesn’t work, the Repair Manual also suggests loosening the four bolts holding the seat in place, retightening them to the specified torque (the same as on fourth-generation Prius cars), and then repeating the calibration. The sensors aren‘t replaced separately; they’re part of the seat adjuster assembly.

Better ghosts, I suppose, than other unexpected front-seat occupants. (Prius cars since 2004 have a similar braking assist feature, part of Toyota’s STAR Safety System. ごめん｡)