Service bulletin 20-AT-001H

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	10170899
Published by NHTSA	2020-02-03
Manufacturer's number	20-AT-001H
Manufacturer's date	2020-01-02
NHTSA component	POWER TRAIN

NHTSA's summary

This TSB provides a procedure to diagnose and repair a transaxle for the following Incorrect Ratio DTC (transaxle clutch slipping more than 200 rpm in gear).

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

Transmission and driveline

Vehicles listed
HYUNDAI ACCENT	2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
HYUNDAI AZERA	2011, 2012, 2013, 2014, 2015, 2016, 2017
HYUNDAI ELANTRA	2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
HYUNDAI ELANTRA GT	2013, 2014, 2015, 2016 (the catalog's model; the bulletin names a series or trim of it)
HYUNDAI ELANTRA GT	2017, 2018, 2019, 2020
HYUNDAI KONA	2018, 2019, 2020
HYUNDAI PALISADE	2020
HYUNDAI SANTA FE	2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
HYUNDAI SANTA FE SPORT	2013, 2014, 2015, 2016, 2017, 2018
HYUNDAI SONATA	2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
HYUNDAI SONATA HYBRID	2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 (the catalog's model; the bulletin names a series or trim of it)
HYUNDAI TUCSON	2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020
HYUNDAI VELOSTER	2013, 2014, 2015
HYUNDAI VELOSTER	2019, 2020

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

Recalls for the same vehicles and component
2018135	2018-03-16. Powertrain
2016436	2016-09-08. Powertrain
16V628000	2016-08-30. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
2016060	2016-02-08. Powertrain
16V057000	2016-01-28. POWER TRAIN:AUTOMATIC TRANSMISSION:COOLING UNIT AND LINES
14V784000	2014-12-09. POWER TRAIN:AXLE ASSEMBLY:AXLE SHAFT
2014323	2014-08-01. Powertrain
14V434000	2014-07-18. POWER TRAIN:AUTOMATIC TRANSMISSION
2013279	2013-08-12. Powertrain
13V355000	2013-08-12. POWER TRAIN:AXLE ASSEMBLY:AXLE SHAFT

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
TXXZ OL	2025-03-01. Warranty extension. Certain 2014 – 2015 model year Tucson vehicles may have a weakened weld at the zone where the center muffler is attached to the exhaust pipe. This condition may cause the center muffler to detach from the exhaust pipe. At Hyundai, we are committed to providing vehicles of outstanding quality and value. In an effort to meet this commitment, Hyundai is extending the warranty coverage for the center muffler assembly under this condition to 15 years / 150,000 miles from the date of original retail delivery or date of first use and is valid for original and subsequent owners.
24-AT-002H	2024-04-16. Service bulletin. This TSB provides a procedure to diagnose and replace, if necessary, an automatic transmission with Incorrect Ratio DTC (transmission clutch slip in gear above limit) listed on Page 2.
24-01-026H	2024-04-16. Service bulletin. Some Santa Fe (CM) vehicles may have an engine that potentially leaks oil from the front cylinder bank’s valve cover onto the alternator. Oil could damage the alternator resulting in illumination of the charging system warning lamp and disablement of the charging system. If the vehicle is continually driven without recharging the battery, the engine will eventually shut off, increasing the risk of a crash. This bulletin outlines the procedures to inspect for T-joint leakage and install an oil protector to address this issue.
24-FL-002H	2024-03-05. Service bulletin. This bulletin provides the procedure to update the Engine Control Module (ECM) and/or the Transmission Control Module (TCM) for 2020-2023MY Sonata (DN8/DN8a) vehicles to improve operation of the Idle Stop and Go (ISG) system. Under certain circumstances the vehicle may not restart after the ISG system has engaged and requires a manual restart due to the lack of intake manifold pressure recovery.
23-EM-009H	2023-12-22. Service bulletin. Certain 2020-2023MY Sonata Hybrid (DN8 HEV) vehicles may exhibit coolant leakage, engine overheating, and white smoke from the exhaust due to an internal leak at the Exhaust Heat Recovery System (EHRS) portion of the center muffler assembly. Follow the procedure outlined in this bulletin to repair this condition after confirming EHRS is leaking internally.
23-01-093H	2023-12-22. Service bulletin. This bulletin provides the procedure to update the Hybrid Control Unit (HCU) and Dual Automatic Temperature Control (DATC) software to help improve coolant flow to the Exhaust Heat Recovery System (EHRS).
23-AT-006H-2	2023-11-30. Service bulletin. This TSB provides information to diagnose the push button shifter operation.
23-01-073H-1	2023-11-07. Service bulletin. Certain 19-23MY Kona Electric (OS EV) vehicles may experience a condition of EV warning light ON with DTC P1AA6 to P1AAF found stored. The Battery Management System (BMS) software update will be performed to enhance battery diagnostics logic. Flowchart summary of the service procedure is provided on page 2 summarized as follows: • Vehicles that do not have EV Warning Light On will only need the BMS software update. • Certain vehicles incurring EV Warning Light On and DTC P1AA6 found stored with Freeze Frame Data Information Code 1=128 will only require the BMS Update. • Certain other DTC P1AA6 Information Code 1-2 values or DTC P1AA7 to P1AAF will require the Battery System Assembly (BSA) to be replaced and then the BMS Update to be performed.
23-01-073H-1	2023-11-07. Service bulletin. Certain 19-23MY Kona Electric (OS EV) vehicles may experience a condition of EV warning light ON with Diagnostic Trouble Code (DTC) P1AA6 to P1AAF found stored. The Battery Management System (BMS) software update will be performed to enhance battery diagnostics logic. The service procedure contained in TSB 23-01-073H-1 (or latest version) is summarized as follows: • Vehicles that do not have EV Warning Light “ON” will only need the BMS software update. • Certain vehicles incurring EV Warning Light “ON” and DTC P1AA6 found stored with Freeze Frame Data Information Code 1=128 will only require the BMS Update. • Certain other DTC P1AA6 Information Code 1-2 values or DTC P1AA7 to P1AAF will require the Battery System Assembly (BSA) to be replaced and then the BMS Update to be performed.
23-01-054H	2023-10-02. Service bulletin. Certain 2013-2015MY Sonata Hybrid (YF HEV) vehicles may exhibit warning lights on while driving and the inability to restart the ignition after it has been turned off when stopped. TSB 23-01-054H outlines the service process to inspect the fuse and safety plug assembly, and replace the parts as needed. This best practice provides helpful tips and key notes when carrying out this service campaign.