2025 Hyundai Tucson DCU Software Update

Why This Matters

Certain 2025 Hyundai Tucson (NX4M) vehicles may experience a Data Communication Unit (DCU) software error. This issue stems from the internal timer initialization logic not being properly implemented, which can lead to the DCU module shutting down telematics services after approximately one year of operation. This means essential connected car features may become unavailable.

What's Being Addressed

Hyundai has released Technical Service Bulletin (TSB) 25-01-060H, also identified as Service Campaign TDFB, to correct a specific software error within the Data Communication Unit (DCU) of the 2025 Hyundai Tucson (NX4M). The TSB outlines a procedure to perform a software update on the DCU module. This update ensures the internal timer initialization logic functions correctly, preventing the premature shutdown of telematics services.

Symptoms of the Hyundai Tucson DCU Error

Owners of affected 2025 Hyundai Tucson vehicles may notice a loss of telematics services after about one year of vehicle operation. This is a direct result of the Hyundai Tucson DCU error where the Data Communication Unit's internal timer initialization logic is not correctly implemented, causing the module to shut down.

Important Warnings for Owners

• Dealer Action: 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. Owners should ask their dealer to check for open campaigns.
• Over-the-Air (OTA) Update: The software update for this Hyundai Tucson DCU error may be available via an Over-the-Air (OTA) update for customers with active Bluelink Services subscriptions.
• Battery Condition: 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.
• During Update:
  • Turn OFF all lamps (do NOT leave head lamp switch in auto mode) and all accessories.
  • Perform the update with the ignition switch in the ON position.
  • 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.
• Update Failure: 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

Dealers will perform a software update on the Data Communication Unit (DCU) using the Global Diagnostic System (GDS). The procedure for Service Campaign 25-01-060H involves several key steps:

1. Preparation: Ensure the vehicle's battery is adequately charged (above 11.0 Volts) and the diagnostic tablet's battery is above 30%. All vehicle lamps and accessories must be turned off, and the ignition switch must be in the ON position.
2. Connection: Connect the diagnostic equipment (VCI 2 or VCI 3 with the Ethernet Communication Interface Kit) to the vehicle's OBD port and the tablet PC. Refer to TSB 23-GI-006H for Ethernet communication setup and TSB # 25-GI-011H for GDS-Smart ECU update procedures.
3. Software Update: The ECU update should initially be performed in Auto Mode. If the update fails in Auto Mode, it can be attempted in Manual Mode.
4. ROM ID Verification: Before proceeding, the technician will verify the current ROM ID against the latest available version (120.NA.012054.012054 for ECU Part Number 96510-N9140).
5. Post-Update: After the update reaches 100%, the ignition must be cycled OFF for at least 10 seconds (up to 30 seconds for some models) to reset the control unit. A screenshot of the