2012 Toyota Prius Owners Manual - Page 475

1-8. Safety information STEP 4 Fully extend the shoulder belt and then allow it to retract slightly in order to activate the ALR lock mode. 1 Lock mode allows the seat belt to retract only. Before driving STEP 5 While pushing the child restraint system down into the rear seat, allow the shoulder belt to retract until the child restraint system 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. 151 PRIUS v_U (OM47674U)