NHTSA Complaint #10760107 — 2004 TOYOTA SIENNA

THE FOLLOWING HAS HAPPENED SEVERAL TIMES OVER THE PAST COUPLE YEARS. THE LATEST 2 TIMES WERE ON A RAMP AT ABOUT 25MPH COMING OFF AN INTERSTATE AND AT ABOUT 65MPH AN INTERSTATE. WHILE CORNERING TO THE LEFT A FAIR AMOUNT, BUT WELL UNDER CONTROL, THE VSC STARTED ALARMING AND KICKED IN. WHEN IT KICKED IN, IT CAUSED THE VEHICLE TO SWERVE HARD TO THE RIGHT AS IF IT HAD LOCKED UP THE BRAKES ON THE RIGHT SIDE OF THE VEHICLE. IN BOTH CASES, THE VEHICLE SWERVED INTO AN ADJACENT LANE. HAD ANYTHING BEEN IN THAT LANE OR HAD WE BEEN IN AN OUTSIDE LANE, THE VCS WOULD HAVE CAUSED A SERIOUS ACCIDENT. WHATEVER THE CAUSE, THE VSC IN THIS VEHICLE IS VERY DANGEROUS. OVER THE 12 YEARS WE'VE OWNED THE VEHICLE, IT'S UNLIKELY THAT THE VSC HAS COME ON MORE THAN 5 TIMES. SINCE IT'S SO RARE, WE DRIVERS HAVE NO EXPERIENCE WITH THE BEHAVIOR AND THE VEHICLE IS COMPLIANT UNTIL THE VSC KICKS IN. WHEN IT KICKS IN, THE CAR HAS PRESUMABLY DETERMINED THAT SOME STABILIZING ACTION NEEDS TO HAPPEN, YET, INSTEAD OF PROVIDING SAFETY - THE VERY PURPOSE OF VCS, IT UNEXPECTEDLY LOCKS UP THE BRAKES ON ONE SIDE OF THE VEHICLE AND CAUSES IT TO SWERVE OUT OF ITS LANE. NOTE, THE VEHICLE HAS RECENTLY HAD A BRAKE JOB. UNDER HARD BRAKING, THE VEHICLE STAYS IN ITS LINE, AND DOES SWERVE AT ALL, SO IT'S WHATEVER THE VSC IS DOING TO "PROVIDE STABILITY" THAT'S CAUSING THE LOCKUP/SWERVE ISSUE. FINALLY, FROM THE INTERNET, A COUPLE QUICK QUERIES LED ME TO POSTINGS BY OTHER SIENNA OWNERS WHO'D EXPERIENCED VERY SIMILAR BEHAVIOR, SO THIS IS NOT AN ISOLATED INCIDENT.