Service bulletin 21-01-017H

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)
Type	Service bulletin
NHTSA id	10189981
Published by NHTSA	2021-04-06
Manufacturer's number	21-01-017H
Manufacturer's date	2021-03-05
NHTSA component	POWER TRAIN; ENGINE AND ENGINE COOLING

NHTSA's summary

This bulletin provides the service procedure to update the Transmission Control Unit (TCU) software for certain Elantra (CN7/CN7a) vehicles equipped with the 2.0L MPI and Intelligent Variable Transmission (IVT). This update to the damper clutch logic is to address a potential engine stall condition immediately following Forward Collision Avoidance (FCA) activation under specific operating conditions at low engine RPM and low vehicle speeds. In the event a low-speed stall does occur, the engine can immediately be restarted.

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, Transmission and driveline

Vehicles listed
HYUNDAI ELANTRA	2021

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

Recalls for the same vehicles and component
2023468	2023-08-18. Powertrain

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
26-EM-016H TSB	2026-10-14. 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 TSB	2026-10-13. 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-EE-003H TSB	2026-04-21. 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-EM-007H TSB	2026-01-06. Service bulletin. Some Elantra (CN7, CN7A), Kona (OS, SX2), and Sonata Hybrid (DN8 HEV) vehicles equipped with 2.0L engines may illuminate a warning lamp for DTC P218100 (Cooling System Performance) related to the Integrated Thermal-Management Module (ITM). Follow the service procedure in this bulletin to install a spring onto the thermostat within the ITM, in order to prevent premature opening, and perform an ECU software update on affected vehicles.
24-FL-003H	2024-04-02. Service bulletin. This bulletin contains the software update procedure for the Engine Control Unit (ECU) on certain 2021-2023MY Elantra (CN7) and 2022-2023MY Kona (OS) vehicles equipped with the 1.6 liter T-GDI Gamma 2 engine, that may exhibit a warning lamp with one or more of the DTCs listed below: • P250F - Engine Oil Level Too Low • P011B, P050C - Engine Coolant Temperature/intake Air Temperature Correlation • P00B7, P2B60 - Engine Coolant Flow Low/Performance
23-EM-005H	2023-12-15. Service bulletin. This bulletin provides important checkpoint guidelines when performing engine oil and filter change services.
23-EE-010H	2023-10-02. Service bulletin. This bulletin is issued to provide the extended battery diagnosis procedure using GDS-M. This battery diagnosis function displays the various battery-related faults such as: • Internal short circuit • Battery deterioration • Malfunction of electronic parts • Insufficient battery charge • Normal battery • Charging defect Battery diagnosis uses the battery sensor history saved for the last 30 days and ICU diagnostic communication to track battery state of charge (SOC) and current parasitic draw history.
23-AT-010H	2023-09-06. Service bulletin. Certain vehicles equipped with the Intelligent Variable Transmission (IVT) may experience a check engine light or malfunction indicator light due to Diagnostic Trouble Codes (DTC) listed below. This bulletin provides information on replacing the oil pressure sensor to remedy these DTCs, rather than replacing the entire IVT assembly.
23-01-014H-5	2023-09-06. Service bulletin. Hyundai has launched an anti-theft software upgrade and window decal campaign (Campaign 993), combined with an anti-theft steering wheel lock campaign (Campaign P32), in response to an increase in thefts of certain 2011-2022MY Hyundai vehicles not equipped with engine immobilizers targeted through social media. For certain vehicles that cannot be updated with the software (Campaign 993), Hyundai is offering customers steering wheel locks at the dealer (Campaign P32). This Dealer Best Practices Guide provides information to assist dealership personnel with customer questions relating to the immobilizer software upgrade, window decals and steering wheel lock ant-theft solutions available from HMA through Hyundai dealers.
23-01-006H	2023-04-04. Service bulletin. This bulletin provides the service procedure to update the Transmission Control Unit (TCU) software for certain Elantra (CN7/CN7a) vehicles equipped with the 2.0L MPI and Intelligent Variable Transmission (IVT). This update to the damper clutch logic is to address a potential engine stall condition immediately following Forward Collision Avoidance (FCA) activation under specific operating conditions at low engine RPM and low vehicle speeds. In the event a low-speed stall does occur, the engine can immediately be restarted.