Service bulletin TSB_ENG225

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10186043
Published by NHTSA	2021-02-02
Manufacturer's number	TSB_ENG225
Manufacturer's date	2021-01-22
NHTSA component	ENGINE AND ENGINE COOLING; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY

NHTSA's summary

TECHNICAL SERVICE BULLETIN: SERVICE ACTION: CENTER AND REAR MUFFLER INSPECTION AND REPAIR (SA461) - This bulletin provides the procedure to inspect the center muffler on some 2021MY Sorento (MQ4a HEV) vehicles equipped with 1.6L T-GDI engine, produced from September 02, 2020 through December 30, 2020, which may exhibit a poor engine start up due to freezing of condensation in the muffler(s) after parking the vehicle for an extended period of time in cold/freezing temperature. The issue does not affect drivability once the vehicle is started.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Equipment and accessories

Vehicles listed
KIA SORENTO HYBRID	2021 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
2022531	2022-09-20. Accessories

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
TSB_ENG257	2025-12-10. Service bulletin. TECHNICAL SERVICE BULLETIN: ITM REPLACEMENT AND ECM & TCM LOGIC IMPROVEMENT (CA2508) - This bulletin provides information to replace the Integrated Thermal Management Module (ITM) and then upgrade the Engine Control Module ‘ECM’ and (if applicable) the Transmission Control Module ‘TCM’ system software on certain 2021-2023MY Sorento (MQ4a) vehicles produced from September 09, 2020 through December 19, 2023. The affected vehicles may experience an illuminated Multifunction Indicator Lamp (MIL) ‘ON’ with DTC(s) P218100, P2181F0, and/or P2181F1 stored. This condition may occur due to degradation of the diaphragm inside the ITM. There are no drivability or other symptoms associated with this condition.
TSB_ELE271_R3	2025-07-23. Service bulletin. TECHNICAL SERVICE BULLETIN: SERVICE ACTION: INVERTER COOLANT/DEBRIS FLUSHING /REPLACEMENT FOR CLUSTER MESSAGE “REFILL INVERTER COOLANT” (SA515) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to flush out the inverter low-conductivity coolant (BSC-1) on certain 2021-2022MY Sorento HEV (MQ4 HEV) vehicles produced from September 2, 2020 through September 29, 2021 and Sorento PHEV (MQ4 PHEV) vehicles produced from June 29, 2021 through October 1, 2021, which may exhibit a “Refill inverter coolant” message displayed on the instrument cluster due to poor flow of coolant/antifreeze inside the low-conductivity coolant pipe. In most cases, the inverter reservoir tank coolant may be filled to normal level and no diagnostic trouble codes (DTC)s are stored due to an increase operation of the electric water pump (EWP) that is 2,800 RPMs or more when checked.
TSB_ ENG256	2025-07-09. Service bulletin. TECHNICAL SERVICE BULLETIN: CONTINUOUS VARIABLE VALVE DURATION (CVVD) ACTUATOR OIL SEAL REPLACEMENT - This bulletin provides information to replace the Continuous Variable Valve Duration (CVVD) Actuator seal on some 2021-2022MY Sorento P/HEV (MQ4 P/HEV) vehicles produced from September 02, 2020, through February 24, 2022. The affected vehicles may experience a slow oil leak coming from the CVVD actuator oil seal and potentially associated oil smell due to the oil seal material degrading over time.
TSB_ENG222_R8	2025-04-18. Service bulletin. TECHNICAL SERVICE BULLETIN: EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information on diagnosing and/or repairing some 2011-2024MY vehicles (refer to the table on pages 9 and 10 for applicable models and engine), which may exhibit a symptom of excessive oil consumption.
TSB_ENG222_R7	2025-03-04. Service bulletin. TECHNICAL SERVICE BULLETIN: EXCESSIVE OIL CONSUMPTION NU/GAMMA/THETA/KAPPA ENGINES - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information on diagnosing and/or repairing some 2011-2024MY vehicles (refer to the tables on pages 8-9 for applicable models and engine), which may exhibit a symptom of excessive oil consumption.
TSB_ELE320	2024-01-06. Service bulletin. TECHNICAL SERVICE BULLETIN: AVN 5.0 WIDE SCREEN FREEZING OR MAP DELAY WITH WIRED APPLE CARPLAY - This bulletin provides information to update the software on 5th Generation AVN wide on certain 2020-2023MY Kia vehicles to remedy an inaccurate map location, freezing AVN screen, or experiencing a delay when using Google Maps or Waze through wired Apple CarPlay.
TSB_ELE271_R2	2023-11-03. Service bulletin. TECHNICAL SERVICE BULLETIN: SERVICE ACTION: INVERTER COOLANT/DEBRIS FLUSHING/REPLACEMENT FOR CLUSTER MESSAGE "REFILL INVERTER COOLANT" (SA515) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to flush out the inverter low-conductivity coolant (BSC-1) on certain 2021-2022MY Sorento HEV (MQ4 HEV) vehicles produced from September 2, 2020 through September 29, 2021 and Sorento PHEV (MQ4 PHEV) vehicles produced from June 29, 2021 through October 1, 2021, which may exhibit a "Refill inverter coolant" message displayed on the instrument cluster due to poor flow of coolant/antifreeze inside the low-conductivity coolant pipe. In most cases, the inverter reservoir tank coolant may be filled to normal level and no diagnostic trouble codes (DTC)s are stored due to an increase operation of the electric water pump (EWP) that is 2,800 RPMs or more when checked.
CS2304_TSB_R6	2023-11-03. Service bulletin. TECHNICAL SERVICE BULLETIN: CUSTOMER SATISFACTION: ANTI-THEFT S/W LOGIC UPGRADE & DECAL INSTALLATION (CS2304) - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides the procedure to upgrade the software logic of the Integrated Body Control Unit (IBU) or Body Control Module (BCM), or Intelligent Integrated Platform Module (IPM) system on certain 2011-2015MY Sorento (XMa), 2016-2020MY Sorento (UMa), and 2021-2022MY Sorento (MQ4a) vehicles produced within the dates outlined on page 10, which may not be equipped with an immobilizer. This logic upgrade will add anti-theft ignition start logic to the vehicle's system operation which activates when the vehicle is locked.
TSB_ELE303_R1	2023-10-01. Service bulletin. This bulletin provides information to update the software on 5th Generation AVN wide on certain 2020-2024MY Kia vehicles (refer to model list on page 3) to remedy a 'non-responsive' or 'inoperative' radio (FM, AM, SXM, etc. ) concern. The affected AVN unit on the vehicles may not respond when pressing the 'RADIO' hard key/button on the AVN unit or when selecting the 'RADIO' icon on the AVN menu screen.
TSB_ELE229_R4	2023-08-02. Service bulletin. TECHNICAL SERVICE BULLETIN: DISPLAY AUDIO 2.0 VALUE SOFTWARE UPDATE FOR WIRELESS CARPLAY IMPROVEMENT - This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides the procedure to update the head unit software on some 2021MY K5 (DL3a), Sorento (MQ4a), and Sorento Hybrid (MQ4 HEV) vehicles equipped with a Display Audio 2.0 Value head unit, which may exhibit a wireless CarPlay connectivity issue with Apple phones running iOS14 software version.