2021-2022 Hyundai Rough Shift and Hesitation TSB

Hyundai has issued Technical Service Bulletin (TSB) 24-AT-001H to resolve concerns regarding rough shifting, hesitation during acceleration, and judder when the Idle Stop & Go (ISG) system is active. This bulletin applies to certain 2021-2022 Hyundai Sonata, Tucson, Santa Cruz, and Santa Fe vehicles equipped with the 2.5L GDI engine. The solution involves updating the software for the Transmission Control Unit (TCU) and, for Santa Fe models, the Engine Control Unit (ECU).

Symptoms

Owners of affected 2021-2022 Hyundai vehicles may experience the following issues:

• Rough shifting: The transmission may feel harsh or abrupt when changing gears.
• Hesitation during acceleration: The vehicle might not respond smoothly or promptly when the accelerator pedal is pressed.
• Judder with ISG enabled: A vibration or shuddering sensation may occur when the Idle Stop & Go system is active.

These symptoms are addressed by the software updates outlined in TSB 24-AT-001H. If you are experiencing a rough shift in your Hyundai Tucson, this bulletin provides a solution.

Diagnosis and Trigger Conditions

The conditions for these symptoms are typically related to the vehicle's transmission and engine control logic. The software update aims to improve the shift quality and responsiveness of the automatic transmission. The GDS (Global Diagnostic System) is used by technicians to identify the specific software event numbers associated with these issues for each model:

• Event #1060: DN8A 2.5GDI ROUGH SHIFT AND HESITATION IMPROVED LOGIC (TCU) for Sonata.
• Event #1061: NX4A 2.5GDI ROUGH SHIFT AND HESITATION IMPROVED LOGIC (TCU) for Tucson.
• Event #1062: NX4A OB 2.5GDI ROUGH SHIFT AND HESITATION IMPROVED LOGIC (TCU) for Santa Cruz.
• Event #1063: TMA 2.5GDI ROUGH SHIFT AND HESITATION IMPROVED LOGIC (TCU) for Santa Fe.
• Event #1065: TMA 2.5GDI ROUGH SHIFT AND HESITATION IMPROVED LOGIC (ECU) for Santa Fe.

Repair Procedure Summary

The repair involves updating the Transmission Control Unit (TCU) software for all listed models and the Engine Control Unit (ECU) software specifically for the Santa Fe (TMA) models. This is performed using the GDS system.

1. Software Update: The technician will perform the ECU/TCU update in "Auto Mode" using the GDS. They will verify the ECU ROM ID before proceeding. If the update fails in Auto Mode, it will be attempted in "Manual Mode" for recovery.
2. Documentation: A screenshot of the "TCU Update Complete" or "ECU Update Complete" screen is taken for repair validation.
3. Control Unit Reset: After the update shows 100% completion, the ignition key is cycled to the OFF position for at least 10 seconds to reset the control unit.
4. DTC Clearance: An "All Systems Fault Code" search is performed, and any incidentally occurred Diagnostic Trouble Codes (DTCs) from the ECU update process are cleared.
5. Verification: The engine is started, and the vehicle is driven to confirm proper transmission operation and that the rough shift issue is resolved.

The bulletin references TSB 15-GI-001 for additional information on tablet-based Mobile GDS ECU updates.

Important Warnings

Owners and technicians should be aware of the following critical information:

• Battery Voltage: A "GDS Vehicle Battery Low Voltage Warning" may appear if the battery voltage is below 12 volts, specifically "Warning! lower Battery Voltage. BATTERY VOLTAGE: 11.7". If this warning is displayed, a 12V battery charger must be attached to ensure an adequate battery state of charge before proceeding with the update.
• Warranty Claims: Normal warranty applies to this repair. Claims should be submitted as "Warranty" type. If a part needs replacement during this TSB and is under warranty, a separate claim should be submitted. If the part is out of warranty, a Prior Approval request for goodwill consideration is required.

Warranty Information

The repair is covered under normal warranty. The operation codes for this service are:

• 39110FH7: TCM Update (for Sonata, Tucson, Santa Cruz) with an estimated operation time of 0.4 hours.
• 39100F43: ECM Update (for Santa Fe) with an estimated operation time of 0.3 hours.

The Nature Code is I14 and the Cause Code is ZZ3.

Owner Action

If your 2021-2022 Hyundai Sonata, Tucson, Santa Cruz, or Santa Fe is experiencing rough shifts, hesitation, or judder with ISG enabled, you should contact your authorized Hyundai dealership. Inform them about the symptoms and reference Technical Service Bulletin 24-AT-001H. The software update will be performed under warranty.

NHTSA ID: 10251293