TECHNICAL SERVICE BULLETIN CUSTOMER SATISFACTION: ANTI-THEFT S/W LOGIC UPGRADE & DECAL INSTALLATION (CS2303) - This bulletin provides the procedure to upgrade the software logic of the Integrated Body Control Unit (IBU) or Body Control Module (BCM) system on certain 2011-2015MY Optima (TF), 2012-2015MY Optima (QF) and 2016-2020MY Optima (JF, JFa) vehicles produced within the dates outlined on page 10, which may not be equipped with an immobilizer. This logic upgrade will add anti-theft ignition start logic to the vehicle's system operation.