TECHNICAL SERVICE BULLETIN: ECM SOFTWARE LOGIC IMPROVEMENT FOR DTC U134100 - This bulletin provides information to upgrade the Engine Control Module (ECM) software logic on certain 2021-2022MY Niro PHEV (DE PHEV) vehicles equipped with 1.6 GDI Kappa, produced from December 23, 2020 through April 13, 2022, which may exhibit a "Check Hybrid System" message displayed on the instrument cluster with DTC U134100 stored. This condition may occur when the ECM tries to communicate via CAN with the Integrated Electronic Brake Module (IEB) while it is in sleep mode due to the vehicle being charged.
