2025 Hyundai Tucson DCU Software Update (25-01-059H)

Hyundai has released Service Campaign 25-01-059H to address a potential issue with the Data Communication Unit (DCU) software in certain 2025 Tucson (NX4) vehicles. This bulletin, also known as SERVICE CAMPAIGN TDFA, provides instructions for dealers to perform a necessary software update.

The core problem is a Hyundai Tucson DCU error stemming from the internal timer initialization logic not being properly implemented in the DCU module. This oversight could lead to the DCU module shutting down telematics services after the vehicle has been in operation for one year. This software update aims to prevent this service interruption and ensure continuous functionality of telematics features.

Why This Matters

The Data Communication Unit (DCU) is crucial for your vehicle's telematics services, which can include features like emergency assistance, navigation, and remote services. If the DCU module were to shut down, as described by the Hyundai Tucson DCU error, these important services would become unavailable after approximately one year of vehicle ownership. This campaign ensures that your vehicle's telematics system remains fully operational.

What's Being Addressed

This service campaign specifically targets a software error within the Data Communication Unit (DCU) of affected 2025 Hyundai Tucson (NX4) vehicles. The ECU part number associated with this update is 96510-N9140. The update aims to correct the internal timer initialization logic, preventing the DCU module from prematurely shutting down telematics services.

Important Warnings and Advisories

Hyundai has issued several critical instructions and warnings related to this software update:

• Dealers must perform this service campaign on all affected vehicles prior to customer retail delivery and whenever an affected vehicle is in the shop for any maintenance or repair.
• The software update is subject to an OTA (Over-the-Air) option and may be completed by customers with active Bluelink Services subscriptions.
• You must initially perform the GDS ECU update in Auto Mode. If the ECU update starts but then fails in Auto Mode, perform the update in Manual Mode to recover.
• Ensure the vehicle's battery charge is above 11.0 Volts and the tablet's battery charge is above 30% before performing a software update to avoid update failure.
• Turn OFF all lamps (do NOT leave head lamp switch in auto mode) and all accessories.
• Do NOT disconnect any cables connected to the vehicle or scan tool during the update.
• Do NOT start the engine during the update.
• Do NOT turn OFF the ignition switch during the update.
• Technicians must check the current ROM ID version and compare it to the ROM ID Information table before attempting to perform the software update.
• If the update fails, remove the power connector from the in-cabin fuse box for at least 5 seconds, or disconnect the negative (-) 12V battery terminal then wait at least 5 seconds. Reassemble and retry the update.

Repair Procedure Summary

The repair for the Hyundai Tucson DCU error involves a software update to the Data Communication Unit (DCU) module. The general procedure for technicians is as follows:

1. Configure Ethernet Communication: This involves connecting the Ethernet Communication Interface (ECI) DLC cable to the OBD connector, then connecting the VCI DLC cable to the ECI. The appropriate tablet cable is then connected to the ECI and the tablet PC. This step may require referring to TSB 23-GI-006H for detailed setup information.
2. Perform ECU Update: The update is initially performed in Auto Mode using the GDS system. Technicians may need to consult TSB 25-GI-011H for guidance on the ECU Update Procedure for Tablet-Based GDS-Smart.
3. Verify ROM ID: Before proceeding, the current ROM ID is checked against the latest available versions to ensure the update is necessary and correct.
4. Ignition Cycle: After the update reaches 100% completion, the ignition must be cycled OFF for 10 to 30 seconds to reset the control unit.
5. OTA Initialization: The Over-the-Air (OTA) initialization should occur automatically. If it fails, it must be performed manually through the S/W Management menu, specifically under CCU_CCNF (Central Communication Unit) > OTA Initialization.
6. Documentation and Fault Code Clearing: A screenshot of the