2024-2025 Hyundai Sonata, Tucson DTC P2B59F0 TSB

Owners of certain 2024-2025 Hyundai Sonata (DN8) and Tucson (NX4/NX4A/NX4M) vehicles equipped with the 2.5L Theta III GDI engine may encounter a warning lamp illumination and the storage of Diagnostic Trouble Code (DTC) P2B59F0. This issue is attributed to a logic error within the Integrated Thermal Management Module (ITM) circuit. To correct this condition, Hyundai has issued TSB 26-EM-009H, which provides instructions for an Engine Control Module (ECM) software update.

This bulletin specifically addresses the Hyundai Tucson DTC P2B59F0 and similar issues in affected Sonata models, aiming to improve the ITM logic through a software revision.

Important Warnings for Owners and Technicians

Hyundai emphasizes several critical points regarding this service bulletin:

• This field action requires a confirmed customer concern and a verified symptom related to the TSB before any repair work can begin. Claims submitted without meeting these justification requirements may be subject to debit.
• The vehicle's battery charge must be above 11.0 Volts, and the diagnostic tablet's battery charge must be above 30% before performing the software update to prevent update failure.
• During the update, ensure all lamps are turned OFF, and do NOT leave the headlamp switch in auto mode. All accessories should also be off.
• Do NOT disconnect any cables connected to the vehicle or the scan tool during the update process.
• Do NOT start the engine or place the vehicle in "Ready" mode while the update is in progress.
• Do NOT turn OFF the ignition switch during the software update.

Symptoms

Owners may notice a warning lamp illuminated on their instrument cluster. This warning is typically accompanied by the storage of a specific Diagnostic Trouble Code (DTC).

Fault Codes / DTCs

The primary diagnostic trouble code associated with this issue is:

Code	Description	Module
P2B59F0	Engine Coolant Flow Control Valve Control Circuit/Open	ECM

Diagnosis / Trigger Conditions

Diagnosis for the Hyundai Tucson DTC P2B59F0 requires a customer concern and a confirmed symptom. Technicians will utilize the GDS e-Report system, which automatically uploads DTCs during diagnosis, to verify the issue. The presence of DTC P2B59F0 indicates a logic error within the Integrated Thermal Management Module (ITM) circuit, necessitating an ECM software update.

Repair Procedure Summary

The repair involves updating the Engine Control Module (ECM) software using a Hyundai diagnostic tool. The general steps are:

1. Ensure the vehicle and tablet battery charge levels meet the specified minimums (vehicle > 11.0 Volts, tablet > 30%).
2. Perform the ECM software update in Manual Mode. Technicians should refer to TSB 25-GI-011H, "ECU Update Procedure for Tablet-Based GDS-Smart," for detailed instructions on using the diagnostic tool.
3. Verify the current ROM ID of the vehicle's ECM by scanning the ENGINE system and compare it to the ROM ID information provided in the TSB to ensure compatibility before proceeding with the update.
4. If the update fails, remove the power connector from the in-cabin fuse box for at least 5 seconds, then reassemble and retry.
5. After the update reaches 100% completion, follow the on-screen prompts to cycle the ignition OFF for 10 to 30 seconds to reset the control unit.
6. Take a screenshot of the ECU Update "Success" screen for digital documentation.
7. Perform an "All Systems Fault Code" search and erase any DTC history that may have incidentally occurred during the update process.
8. Start the engine to confirm proper vehicle operation.

Required Tools or Parts

Technicians will need specific tools to perform this software update:

• VCI 3 (Tool Number: GOVHNNN06)
• VCI 2 (Tool Number: G1XDDMN001): While VCI 2 can be used for these updates, it is no longer available for order.

Specific causal part numbers for warranty claims include 39104-2S205, 39110-2S356, 39110-2S364, and 39104-2S440.

ROM ID Information

The TSB includes extensive tables detailing current and latest ROM IDs for various ECU part numbers across different models and event numbers. These tables are crucial for technicians to verify the correct software version for the ECM update. For example, for the Tucson (NX4) with event 1255, ECU part numbers like 39110-2S356, 39104-2S403, and others are listed with their corresponding ROM IDs (e.g., NXFVD5GMAXXX1Q2A to NXFVD5GMAXXX1Q6A). Similar detailed information is provided for Sonata (DN8) models.

Warranty Information

This field action is covered under the 8-year / 80,000-mile Emissions Warranty. Claims must be submitted as a "Campaign" type. Prior to any repair work, technicians must ensure that the affected parts and repair procedures fall within the emissions warranty coverage, considering mileage and warranty start date. If the parts are out of warranty, retailers may submit a Prior Approval (PA) Request for goodwill consideration on a case-by-case basis.

Owner Action

If your 2024-2025 Hyundai Sonata or Hyundai Tucson DTC P2B59F0 warning lamp is illuminated, or you suspect an issue related to the Engine Coolant Flow Control Valve or Integrated Thermal Management Module, contact your authorized Hyundai dealership. Inform them of the symptoms you are experiencing and reference TSB 26-EM-009H. The dealership will diagnose the issue and perform the necessary ECM software update.

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Source: NHTSA ID: 11030329