VOLUNTARY EMISSIONS SERVICE CAMPAIGN: NU 2.OL GDI SULEV ECU EMISSIONS LOGIC IMPROVEMENT (SC251) - This bulletin provides the procedure to update the emissions-related logic of the Electronic Control Module (ECM) with an improved version on certain 2017-2019MY Soul (PS) vehicles equipped with the Nu 2.0L GDI SULEV engine, produced from July 29, 2016 through December 19, 2018. To ensure compliance with emissions regulations, apply the improved software update to the Engine system using the KDS ECU Upgrade function as described in this bulletin.