2023 Kia Sportage Cooling System Performance TSB

Owners of certain 2023 Kia Sportage vehicles may experience an illuminated Multifunction Indicator Lamp (MIL) on their dashboard. This condition is often accompanied by specific diagnostic trouble codes (DTCs) related to the cooling system. This technical service bulletin (TSB) addresses the underlying cause and provides a repair procedure for the Kia Sportage cooling system performance issue. The TSB, identified as ENG259 (Rev 1), was issued in October 2025 and revised on November 6, 2025, to include additional information.

Symptoms

The most common symptom owners will notice is the illumination of the "Multifunction Indicator Lamp (MIL) 'ON'" on the instrument cluster. This warning light indicates that the vehicle's engine control system has detected a fault. Despite the warning, drivers typically will not experience any changes in how the vehicle drives, as Kia notes there are no drivability or other symptoms associated with this condition.

Fault codes / DTCs

When the Multifunction Indicator Lamp illuminates due to this issue, one or more of the following diagnostic trouble codes (DTCs) will be stored in the vehicle's Engine Control Module (ECM):

Code	Description
P218100	Cooling System Performance
P2181F0	Cooling System Performance
P2181F1	Cooling System Performance

These codes specifically point to a problem with the Kia Sportage cooling system performance, prompting the need for further diagnosis and repair.

Diagnosis / trigger conditions

The condition is triggered by the degradation of the diaphragm located inside the Integrated Thermal Management Module (ITM). When this degradation occurs, the Engine Control Module (ECM) detects a cooling system performance issue and stores the relevant DTCs, leading to the illumination of the "Multifunction Indicator Lamp (MIL) 'ON'". Technicians will confirm the presence of these DTCs to diagnose the issue, and a Vehicle Diagnosis Number (VDN) must be created before proceeding with parts ordering or repairs.

Important Warnings and Owner Information

Kia has provided several critical advisories for both technicians and owners regarding this service bulletin:

• No Customer Notification: This Technical Service Bulletin is a field fix repair program and Kia is NOT notifying consumers directly. Owners must be proactive in checking for this issue.
• VDN Requirement: A "Vehicle Diagnosis Number (VDN)" must be created for the stored DTCs prior to ordering parts and performing any necessary procedures. Failure to create a VDN will result in issues with parts ordering and warranty claim submission, and any claims for replacement parts will be subject to warranty review and chargeback.
• MIL 'ON' Confirmation: The bulletin should only be performed if the "Multifunction Indicator Lamp (MIL) 'ON'" is stated in the opening Repair Order (RO) and Claim Notes, along with the related DTCs.
• ITM Disassembly: Technicians are instructed to DO NOT disassemble the actuator and collector of the Integrated Thermal Management Module (ITM), as the new ITM is supplied as a complete assembly unit.
• ITM Connection Orientation: The ITM connection orientation changes with the new part; the locking tab will face the engine. Attempting to connect the new ITM in the same orientation as the original may damage the connector pins/terminals.
• ECU Programming Mode: The ECU and TCM MUST be programmed in Manual Mode ONLY using the KDS 2.0 download, not Auto Mode.
• Pre-Upgrade Checks: Before performing the ECM software upgrade, ensure the battery is fully charged (12.3 volts or higher) or use a jump starter box. The Kia Diagnostic System (KDS) Global Diagnostic System (GDS) must be at 60% charge or higher. All ECU upgrades require the ignition to be 'ON'.
• VCI-II Usage: Damaged VCI-II units should not be used and must be replaced. Technicians must be careful not to disconnect the VCI-II during the upgrade procedure.
• Engine Operation During Upgrade: DO NOT start the engine during the ECU upgrade.
• Ignition During Upgrade: DO NOT turn the ignition key 'OFF' or interrupt the power supply during the ECU upgrade. Once the upgrade is complete, turn the ignition 'OFF' and wait 10 seconds before starting the engine.
• Immobilizer System: Before any ECU upgrade, technicians must determine if the vehicle has an immobilizer security system. Failure to follow proper procedures may cause the PCM to become inoperative after the upgrade, leading to potential chargebacks for repair claims.
• Parts Availability: Replacement part numbers require a VIN entry for ordering and should NOT be ordered for stocking purposes. Supply is very limited, and technicians must confirm part availability before scheduling customers.

Repair procedure summary

The repair involves replacing the Integrated Thermal Management Module (ITM) and then upgrading the Engine Control Module (ECM) software. The procedure is as follows:

1. ITM Replacement: The Integrated Thermal Management Module (ITM), identified as component 'A' in the service manual diagrams, is replaced. Technicians must refer to the 'Engine Mechanical System → Cooling System → Integrated Thermal Management Module (ITM) → Repair procedures' section in the applicable Shop Manual on KGIS for detailed instructions. The bolts for the ITM should be tightened to a torque of 7.2 - 8.7 lb.ft (9.8 - 11.8 N.m).
2. Reinstallation: All removed parts are reinstalled in the reverse order of removal.
3. O-ring Installation: A new inlet pipe O-ring, marked as 'B' in the diagrams, is installed in the red-circled area shown in the service manual.
4. ECM Software Upgrade: After the ITM replacement is complete, the Engine Control Module (ECM) is upgraded with Event 854 software. This upgrade must be performed in Manual Mode only using the Kia Diagnostic System (KDS) tablet and VCI-II, following instructions in TSB SST081. Technicians will reference ROM ID tables to ensure the correct software is applied.
5. Verification: Finally, normal vehicle operation is verified.

Required tools or parts

To perform this repair, specific tools and parts are required:

• Diagnostic System: Kia Diagnostic System (KDS) with VCI-II interface (Part Number: N/A)
• Integrated Thermal Management Module (ITM): Part Number 25600 25650QQK (Quantity: 1)
• Water Inlet Pipe O-ring: Part Number 25462 2SOOOQQK (Quantity: 1)
• Coolant (Prediluted): Part Number UM020 CH263 (Quantity: 2 gallons)

Warranty Information

This repair is covered under warranty with the following details:

• Claim Type: V (Warranty)
• N Code: N99
• C Code: C99
• Causal Part Numbers: 39100 2S210 (for NQ5 Korea models) or 39100 2S226 (for NQ5a USA models)
• Repair Description: ITM Replacement & ECM Logic Improvement (CA2509)
• Labor Operation Codes: 250139RO (for NQ5 Korea) or 250A40RO (for NQ5a USA)
• Operation Time: 1.7 Man-Hours (M/H)
• Replacement Part Numbers: 25600 25650QQK (ITM), 25462 2SOOOQQK (O-ring), UM020 CH263 (Coolant)

If substitute transportation is provided to the customer, technicians should manually enter sublet code 'X2' for rental expense reimbursement or one roundtrip rideshare expense. This claim must be submitted at the time of the warranty expense.

Owner action

If your 2023 Kia Sportage is displaying the "Multifunction Indicator Lamp (MIL) 'ON'" and you suspect a Kia Sportage cooling system performance issue, it is recommended to visit your authorized Kia dealer. Ensure the dealer is aware of the illuminated MIL and any diagnostic trouble codes (DTCs) such as P218100, P2181F0, or P2181F1. The repair involves replacing the Integrated Thermal Management Module (ITM) and updating the Engine Control Module (ECM) software, which should be covered under Kia's Basic Limited Warranty Coverage. Remember that a Vehicle Diagnosis Number (VDN) is required by the dealer for proper processing of the repair and parts.

Source: NHTSA TSB ENG259 (Rev 1)