2010 Toyota Sienna Owners Manual - Page 178

1-7. Safety information STEP 2 Run the seat belt through the child seat and insert the plate into the buckle. Make sure that the belt is not twisted. 1 Before driving STEP 3 Fully extend the shoulder belt and then allow it to retract slightly in order to activate the ALR lock mode. Lock mode allows the seat belt to retract only. STEP 4 While pushing the child seat down into the rear seat, allow the shoulder belt to retract until the child seat is securely in place. After the shoulder belt has retracted to a point where there is no slack in the belt, pull the belt to check that it cannot be extended.