# Service campaign 25\-01\-018H\-1 TSB

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service campaign
- NHTSA id: 11018574
- Published by NHTSA: 2025\-05\-27
- Manufacturer's number: 25\-01\-018H\-1 TSB
- Manufacturer's date: 2025\-05\-08
- Campaign id or software version: 9C0
- NHTSA component: ELECTRICAL SYSTEM

## NHTSA's summary

Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink functions. This may be due to an occasional disconnection on Verizon’s communication network. Follow the procedures in this bulletin to verify Bluelink Data Communication Unit \(DCU\) network connection and if needed, reset the DCU in Dealer Mode to resolve the connection.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11018574-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11018574-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system

## Vehicles listed

- 2025 HYUNDAI IONIQ 5
- 2025 HYUNDAI IONIQ 5 N
- 2024 to 2025 HYUNDAI KONA
- 2024 to 2025 HYUNDAI KONA ELECTRIC
- 2025 HYUNDAI SANTA CRUZ
- 2024 to 2025 HYUNDAI SANTA FE
- 2024 to 2025 HYUNDAI SANTA FE HYBRID
- 2024 to 2025 HYUNDAI SONATA
- 2024 to 2025 HYUNDAI SONATA HYBRID
- 2025 HYUNDAI TUCSON
- 2025 HYUNDAI TUCSON HYBRID
- 2025 HYUNDAI TUCSON PLUG\-IN HYBRID

## Recalls for the same vehicles and component

- [26V400000](/recalls/nhtsa/26V400000.md), 2026-06-23: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [26V068000](/recalls/nhtsa/26V068000.md), 2026-02-05: ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY
- [26V047000](/recalls/nhtsa/26V047000.md), 2026-01-26: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [2025529](/recalls/tc/2025529.md), 2025-10-02: Electrical
- [25V659000](/recalls/nhtsa/25V659000.md), 2025-10-02: ELECTRICAL SYSTEM:STARTER ASSEMBLY
- [25V482000](/recalls/nhtsa/25V482000.md), 2025-07-23: ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY
- [25V064000](/recalls/nhtsa/25V064000.md), 2025-02-06: AIR BAGS:SIDE/WINDOW; ELECTRICAL SYSTEM:WIRING
- [2024708](/recalls/tc/2024708.md), 2024-11-20: Electrical
- [24V877000](/recalls/nhtsa/24V877000.md), 2024-11-20: ELECTRICAL SYSTEM:WIRING
- [24V843000](/recalls/nhtsa/24V843000.md), 2024-11-07: ELECTRICAL SYSTEM:WIRING:SWITCHES/KNOBS/BUTTONS; VISIBILITY:SUN/MOON ROOF ASSEMBLY

## Other bulletins for the same vehicles and component

- [26\-01\-082H TSB](/bulletins/11038467.md), 2026-10-14, Warranty extension: ELECTRICAL SYSTEM. Certain IONIQ 5 \(NEA EV\) vehicles may experience Malfunction Indicator Lamp \(MIL\) illumination and false battery overtemperature fault diagnosis caused by water ingress into the high voltage battery system. This condition may cause unnecessary fail\-safe activation, potentially resulting in reduced vehicle performance or limited vehicle operation if the vehicle is continually driven. This bulletin provides the service procedure to update the Battery Management System \(BMS\) software to optimize the fail\-safe activation logic to prevent false activation. Additionally, diagnostic criteria for DTC P1AD300 “Hybrid/EV Battery Abnormal Performance: MISD” has also been improved to enhance diagnostic accuracy.
- [26\-01\-082H DCS](/bulletins/11038466.md), 2026-10-14, Warranty extension: ELECTRICAL SYSTEM. Certain IONIQ 5 \(NEA EV\) vehicles may experience Malfunction Indicator Lamp \(MIL\) illumination and false battery overtemperature fault diagnosis caused by water ingress into the high\-voltage battery system. This condition may cause unnecessary fail\-safe activation, potentially resulting in reduced vehicle performance or limited vehicle operation if the vehicle is continually driven.
- [26\-BE\-025H TSB](/bulletins/11037232.md), 2026-09-09, Service bulletin: ELECTRICAL SYSTEM. Some Tucson \(NX4, NX4A, NX4M\), Tucson Hybrid \(NX4 HEV\), and Tucson Plug\-In Hybrid \(NX4 PHEV\) vehicles may exhibit a 12\-volt battery drain due to the passive entry feature of the Digital Key 2 premium causing repeated wakeup of the vehicle. This bulletin provides instructions to perform software updates for the Ultra\-Wide Band \(UWB\) and Body Domain Control \(BDC\) modules.
- [26\-BE\-026H TSB](/bulletins/11036624.md), 2026-09-02, Service bulletin: ELECTRICAL SYSTEM. Some Santa Fe \(MX5A\) and Santa Fe Hybrid \(MX5A HEV\) vehicles may exhibit a 12\-volt battery drain due to the passive entry feature of the Digital Key 2 premium causing repeated wakeup of the vehicle. This bulletin provides instructions to perform software updates for the Ultra\-Wide Band \(UWB\) and Body Domain Control \(BDC\) modules.
- [LA29\-LA30 DCS](/bulletins/11035142.md), 2026-07-21, Warranty extension: ELECTRICAL SYSTEM. Certain 2024\-2026MY Sonata \(DN8\) and 2024\-2026MY Sonata Hybrid \(DN8 HEV\) vehicles may exhibit intermittent battery discharge condition due to the air conditioning controller not fully powering down after the vehicle is turned off and parked. Technical Service Bulletins \(TSB\) 26\-01\-051H \& 26\-01\-052H provide the procedure to update the ATCU \(Air Temperature Control Unit\) software; the revised logic improves controller shutdown to prevent battery drain and corrects a condition where the HVAC control display may appear blank when climate remote start is activated via Bluelink. Over\-the\-Air \(OTA\): This update can also be conducted via OTA. Customers can complete on their own if they have an active subscription to Hyundai Bluelink. A visit to the dealership is not required. Deployment of the OTA to Bluelink customers is planned to start the week of 07/13/26.
- [26\-01\-052H TSB](/bulletins/11035141.md), 2026-07-21, Warranty extension: ELECTRICAL SYSTEM. Certain Sonata Hybrid \(DN8 HEV\) vehicles may exhibit intermittent battery discharge conditions due to the air conditioning controller not fully powering down after the vehicle is turned off and parked. This bulletin provides the procedure to update the Air Temperature Control Unit \(ATCU\) software; the revised logic improves controller shutdown to prevent battery drain and corrects a condition where the HVAC control display may appear blank when climate remote start is activated via Bluelink.
- [7/13/2026 TSB](/bulletins/11035140.md), 2026-07-21, Warranty extension: ELECTRICAL SYSTEM. Certain Sonata \(DN8\) vehicles may exhibit intermittent battery discharge condition due to the air conditioning controller not fully powering down after the vehicle is turned off and parked. This bulletin provides the procedure to update the ATCU \(Air Temperature Control Unit\) software; the revised logic improves controller shutdown to prevent battery drain and corrects a condition where the HVAC control display may appear blank when climate remote start is activated via Bluelink.
- [26\-FL\-003H TSB](/bulletins/11034847.md), 2026-07-08, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Some Kona \(SX2\) vehicles equipped with the 1.6L T‑GDI engine may exhibit false “engine left idling” notifications in the MyHyundai app, even when the engine is not running, due to a logic error associated with the front oxygen \(O₂\) sensor. This condition may also illuminate the Malfunction Indicator Lamp \(MIL\) and set DTC P223700 \(O₂ Sensor Pumping Current Circuit/Open \[Bank 1 Sensor 1\]\). This bulletin provides instructions to perform an ECU software update to correct the O₂ sensor logic and resolve the condition.
- [Z14 OL](/bulletins/11034111.md), 2026-06-27, Warranty extension: FUEL/PROPULSION SYSTEM; ELECTRICAL SYSTEM. Certain 2022 – 2024 model year IONIQ 5, 2024 model year IONIQ 5 Robotaxi, and 2023 – 2025 model year IONIQ 6 vehicles may require a replacement of the Integrated Charging Control Unit \(ICCU\) and ICCU Fuse. At Hyundai, we are committed to providing vehicles of outstanding quality and value. In an effort to meet this commitment, the warranty coverage for the Integrated Charging Control Unit \(ICCU\) and ICCU Fuse Replacement has been extended to 15 years/ 180,000 miles from the date of original retail delivery or date of first use \(whichever occurs first\) and is valid for original and subsequent owners.
- [26\-EE\-007H TSB](/bulletins/11034027.md), 2026-06-23, Service bulletin: ELECTRICAL SYSTEM. Some Palisade \(LX2\), Tucson \(NX4\), and Tucson Hybrid \(NX4 HEV\) vehicles may experience battery drain due to continuous operation of the cooling fan after vehicle ignition has been turned off, potentially resulting in a no\-start condition. The continuous cooling fan operation is caused by a stuck relay in the engine room PCB block. This bulletin provides instructions to replace the engine room PCB block to ensure the proper operation of the cooling fan.

JSON: [/v1/bulletins/11018574](/v1/bulletins/11018574)

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