2021-2023 Hyundai N 8-Speed DCT Learning Update

Hyundai has issued Technical Service Bulletin (TSB) 23-AT-013H to address and improve the performance of the 8-speed wet dual clutch transmission (8WDCT) in certain 2021-2023 Veloster N, Kona N, and Elantra N vehicles. This bulletin focuses on a Transmission Control Unit (TCU) software update designed to enhance the transmission's "touch point learning" capabilities. The goal is to reduce drivability concerns that may arise from variations in this learning process.

The TSB highlights that some 8WDCT units, identified by new part numbers, incorporate an improved clutch spring. It is crucial that the correct TCU software update is applied to match the specific 8WDCT hardware in the vehicle. Failing to do so can lead to various drivability issues.

Symptoms

Owners of affected Hyundai N vehicles may experience several drivability concerns related to the 8-speed wet DCT. These can include:

• Shift shock: Harsh or unexpected shifts during acceleration or deceleration.
• Hesitation or jerking: The vehicle may feel hesitant or jerk during acceleration or when changing gears.
• Rattling: Unusual noises coming from the transmission area.
• Inability to drive forward or reverse: In severe cases, the transmission may fail to engage gears properly.

These symptoms are often linked to the transmission's touch point learning process, which the software update aims to optimize.

Fault Codes / DTCs

Technicians may encounter specific Diagnostic Trouble Codes (DTCs) when diagnosing vehicles with these drivability concerns. The TSB specifically mentions:

If DTC P086800 is detected, the TSB instructs technicians to check and potentially replace the control fluid according to the shop manual.

Important Warnings

Hyundai has provided several critical warnings for technicians and, by extension, for owners to be aware of:

• Software-Hardware Mismatch: "Make sure that the TCU CAL ID is the latest and matches the corresponding part number, otherwise shift shock may occur."