23-EE-002H

This bulletin provides information related to the Engine Control Module (ECM) / Hybrid Control Unit (HCU) software update for Tucson Hybrid (NX4 HEV) / Plug-in Hybrid (NX4 PHEV) vehicles to improve the following DTC and symptoms: 1. P1441 (EVAP System Flow During Non-Purge Condition) a. Misdiagnosis due to insufficient margin of pressure deviation when driving at constant speed with low engine load i. Logic improvement to eliminate misdiagnosis 2. P1A77 (Check Generator Belt) a. Misdiagnosis due to poor synchronization release when the engine is stopped i. Logic improvement to release synchronization even if CAM signal is active when engine is stopped 3. P00B7 (Engine Coolant Flow Low/Performance) a. ITM control error due to temporary ball valve stuck i. Improvement to ITM cleaning logic (1 time -> 5 times) 4. P2118 (Throttle Actuator Control Motor Current Range/Performance) / P0401 (EGR Flow Insufficient Detected) 5. P0236 (Turbocharger System Boost Sensor A Circuit Range/Performance) / P0299 (Turbocharger underboost) a. Failure due to EGR condensate freezing i. Change the EGR Flow diagnosis condition (-40℃ → -7℃) 6. P2B60 (Engine Coolant Flow Control Valve Position Sensor Circuit Range/Performance) a. Insufficient control at the end point when ITM cleaning logic completes operation i. Improve the ITM cleaning logic for better control 7. Oil Dilution: Some vehicles may experience increased oil consumption and white smoke due to the diluting of engine oil with fuel because of the frequent transition between EV ↔ Engine mode during the winter season a. Modify fuel injection strategy below 10℃ and add oil heating function based on the driving pattern.