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Service bulletin 26-EM-004H TSB

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11028667
Published by NHTSA2026-02-10
Manufacturer's number26-EM-004H TSB
Manufacturer's date2026-02-05
NHTSA componentENGINE

NHTSA's summary

Some Tucson (NX4, NX4A) vehicles may have DTC P218100, P2181F0, and/or P2181F1 (Cooling System Performance) set in the Electronic Control Unit (ECU), resulting in an illuminated Check Engine warning lamp. This TSB provides instructions to replace the Integrated Thermal Management (ITM) module and update both the Engine Control Module (ECM) and Transmission Control Module (TCM), if applicable. Follow the flowchart in this bulletin to update the appropriate modules.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Trouble codes named

P2181

Vehicles listed
HYUNDAI TUCSON2022, 2023

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
26-01-081H DCS2026-10-14. Service campaign. Certain Santa Fe Hybrid (TM HEV), Santa Fe Plug-in Hybrid (TM PHEV), Tucson Hybrid (NX4 HEV), andTucson Plug-in Hybrid (NX4 PHEV) vehicles may experience intake air line freezing and Exhaust GasRecirculation (EGR) valve corrosion due to excessive condensation accumulating within the EGR system.This condition can lead to drivability concerns related to the following DTCs: - P040400: (Exhaust Gas Recirculation Control Circuit Range) - P049D00: (EGR 'A' Control Position Exceeded Learning Limit) - P047100: (Exhaust Pressure Sensor 'A' Circuit Range/Performance) - P012800: Coolant Thermostat (Coolant Temperature below Thermostat Regulation Temperature) - P262B00: (Control Module Power Off Timer Performance) - P050C00: Cold Start Engine Coolant Temperature Performance - P1DFD00: (EVAP System Purge Pump Target Speed) - P2DFD00: (EVAP System Purge Pump Performance) - P112000: (Inlet Metering Valve – Malfunction) - P033500: (Crankshaft Position Sensor A)
26-EM-016H TSB2026-10-14. Service bulletin. Some vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin outlines the combustion chamber cleaning procedure for vehicles diagnosed with this condition. All internal combustion engines consume some engine oil during normal operation, depending on driving conditions and mileage, and this procedure should only be performed when deemed necessary based on inspection and diagnosis of the vehicle as outlined in TSB 26-EM-015H, Engine Oil Consumption – Inspection & Repair Guidelines, or the latest revision.
26-EM-015H TSB2026-10-13. Service bulletin. Certain vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin provides the inspection and repair procedures for vehicles exhibiting this condition. All internal combustion engines consume engine oil as part of normal engine operation. Oil consumption rates may vary based on mileage, operating conditions, driving habits, and maintenance history. Hyundai recommends following the prescribed maintenance schedule and periodically checking the engine oil level using the dipstick to maintain proper engine oil level.
26-01-081H TSB2026-10-09. Service campaign. Certain Santa Fe Hybrid (TM HEV), Santa Fe Plug-in Hybrid (TM PHEV), Tucson Hybrid (NX4 HEV), and Tucson Plug-in Hybrid (NX4 PHEV) vehicles may experience intake air line freezing and Exhaust Gas Recirculation (EGR) valve corrosion due to excessive condensation accumulating within the EGR system. This condition can lead to drivability concerns related to the following DTCs: • P040400: (Exhaust Gas Recirculation Control Circuit Range) • P049D00: (EGR 'A' Control Position Exceeded Learning Limit) • P047100: (Exhaust Pressure Sensor 'A' Circuit Range/Performance) • P012800: Coolant Thermostat (Coolant Temperature below Thermostat Regulation Temperature) • P262B00: (Control Module Power Off Timer Performance) • P050C00: Cold Start Engine Coolant Temperature Performance • P1DFD00: (EVAP System Purge Pump Target Speed) • P2DFD00: (EVAP System Purge Pump Performance) • P112000: (Inlet Metering Valve – Malfunction) • P033500: (Crankshaft Position Sensor A) The bulletin below provides instructions to perform a software update for the Engine Control Module (ECM).
26-01-081H DN2026-10-09. Service campaign. Certain Santa Fe Hybrid (TM HEV), Santa Fe Plug-in Hybrid (TM PHEV), Tucson Hybrid (NX4 HEV), and Tucson Plug-in Hybrid (NX4 PHEV) vehicles may experience intake air line freezing and Exhaust Gas Recirculation (EGR) valve corrosion due to excessive condensation accumulating within the EGR system. This condition can lead to drivability concerns related to the following DTCs: • P040400: (Exhaust Gas Recirculation Control Circuit Range) • P049D00: (EGR 'A' Control Position Exceeded Learning Limit) • P047100: (Exhaust Pressure Sensor 'A' Circuit Range/Performance) • P012800: Coolant Thermostat (Coolant Temperature below Thermostat Regulation Temperature) • P262B00: (Control Module Power Off Timer Performance) • P050C00: Cold Start Engine Coolant Temperature Performance • P1DFD00: (EVAP System Purge Pump Target Speed) • P2DFD00: (EVAP System Purge Pump Performance) • P112000: (Inlet Metering Valve – Malfunction) • P033500: (Crankshaft Position Sensor A)
26-EE-003H TSB2026-04-21. Service bulletin. Some vehicles may exhibit difficulty starting in cold weather. This bulletin provides the procedure to perform an inspection on the starter magnetic switch for potential freezing and, if necessary, replace the starter magnetic switch (solenoid) assembly.
25-01-064H TSB2025-10-01. Service campaign. Certain Santa Fe Plug-in Hybrid (TM PHEV) and Tucson Plug-in Hybrid (NX4 PHEV) vehicles may exhibit a restricted coolant flow condition, which may be accompanied by a warning message (e.g., Coolant Supplement, Refill Inverter Coolant) in the cluster. No related DTCs are stored, and coolant level is normal in the reservoir tank. The coolant flow may be restricted by debris, causing abnormally high Electric Water Pump (EWP) speed. This TSB contains instructions for confirming high RPMs in the EWP, then using the Coolant Flushing Equipment Set to flush and clean debris from the various cooling system circuits. The coolant will be replaced with the updated Electric Vehicle Battery System Coolant (BSC-2) low-conductivity blue coolant.
25-01-065H TSB2025-10-01. Service campaign. Certain Santa Fe Hybrid (TM HEV) and Tucson Hybrid (NX4 HEV) vehicles may exhibit a restricted coolant flow condition, which may be accompanied by a warning message (e.g., Coolant Supplement, Refill Inverter Coolant) in the cluster. No related DTCs are stored, and coolant level is normal in the reservoir tank. The coolant flow may be restricted by debris, causing abnormally high Electric Water Pump (EWP) speed. This TSB contains instructions for confirming high RPMs in the EWP, then using the Coolant Flushing Equipment Set to flush and clean debris from the various cooling system circuits. The existing blue coolant, Electric Vehicle Battery System Coolant (BSC-2), will be used to flush the system. Then the coolant will be replaced with new pink coolant (LLC-10).
25-EM-002H TSB2025-06-24. Service bulletin. Certain 2020-2022MY Tucson Hybrid and Santa Fe Hybrid vehicles equipped with the 1.6T-GDI Gamma II HEV engine may experience an engine oil leak originating from the Continuous Variable Valve Duration (CVVD) Actuator Oil Seal. Follow the service procedure below to replace the CVVD Oil Seal.
24-EM-001H2024-08-07. Service bulletin. Certain 20-22MY Sonata (DN8a), 21-23MY Santa Fe (TMa), and 22-23MY Tucson (NX4a) vehicles may experience a warning lamp illumination for a diagnostic trouble code P2181 that is related to the Integrated Thermal Management Module (ITM). Follow the service procedure outlined in this bulletin to replace the ITM.