NHTSA ID Number: 11033845
Manufacturer Communication Number: 26-HA-002G TSB
TSB/Document Date: 2026-06-16
Summary
Some Genesis
vehicles (listed below) equipped with Lambda-III 3.5T-GDI engines may exhibit reduced heater performance due to engine coolant deposits clogging the heater core. This bulletin provides instructions to verify the concern and to replace the front and rear heater core (if applicable).
Heater Temperature Difference Check
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
- Preparation
1.
Connect GDS.
2.
Turn ON the IG switch.
3.
Select Data Analysis (A) on the Genesis
Smart home screen.
A
4.
Select ENGINE (B) and press OK.
B
TSB #: 26-HA-002G
Page 5 of 12
SUBJECT:
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
5.
Check the Water Temperature Value (C).
6.
Maintain the engine RPM at 2000-3000 until
the Water Temperature Value is 194°F (90°C)
or higher.
C
7.
Set HVAC temperature to HI (D), fan speed to
4 (E), recirculation mode ON (F), and direct
the airflow to the face vents.
F
D
E
For GV80 (JX1) 7-Passenger models, do the
same settings for the 3rd row.
TSB #: 26-HA-002G
Page 6 of 12
SUBJECT:
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
Heater Temperature Difference Check and Heater Core Replacement
G80 (RG3) , G90 (RS4) , GV70 (JK1, JK1A) , GV80 (JX1 , 5-Passenger )
i
-
Information
For 7-Passenger GV80 (JX1) vehicles, follow the procedure starting on page 9.
1.
Using a thermometer, measure the
temperatures at the front center vents on the
driver side (A) and passenger side (B).
i
Front Center Vents
A
B
Information
Allow adequate time for the vent
temperatures to stabilize.
2.
DIGITAL
DOCUMENTATION
Using the STUI camera function, take a
photo clearly showing the temperature
readings on BOTH thermometers.
Upload the photo to STUI.
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
3.
•
If the temperature difference between the
front center vents is less than 18°F, then
Use OP Code 40D158R0 to finish this
inspection procedure. The service
procedure is now complete.
•
If the temperature difference between the
front center vents is 18°F or higher, then
proceed to step 4 for front heater core
replacement.
TSB #: 26-HA-002G
Page 7 of 12
SUBJECT:
4.
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
Replace the front heater core (C).
Refer to the shop manual:
• Heating, Ventilation and Air
Conditioning > Heater > Heater Core >
o Replacement OR
o Repair procedures OR
o Removal and Installation
C
5.
DIGITAL
DOCUMENTATION
Using the STUI camera function, take a
clear photo of the OLD heater core
removed next to the NEW heater core on
top of the box with the “QQH” label
showing.
NEW
Upload the photo to STUI.
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
5.
Reinstall all components in reverse order of
the removal process.
6.
Perform air bleeding of the coolant.
OLD
Refer to the shop manual:
• Engine Mechanical System > Cooling
System > Coolant >
o Replacement OR
o Repair procedures OR
o Refill
7.
Start the engine and confirm proper vehicle
operation.
TSB #: 26-HA-002G
Page 8 of 12
SUBJECT:
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
Heater Temperature Difference Check and Heater Core/Rear Heater Core Replacement
GV80 (JX1, 7-Passenger)
1.
Using a thermometer, measure the
temperatures at the front center vents on the
driver side (A) and passenger side (B).
i
-
Front Center Vents
B
A
Information
Allow adequate time for the vent
temperatures to stabilize.
2.
Using a thermometer, measure the
temperatures at the rear vents in the 3rd row
on the LH (C) and RH (D) sides.
Rear/3 rd Row Vents
LH SIDE
C
RH SIDE
D
TSB #: 26-HA-002G
Page 9 of 12
SUBJECT:
3.
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
DIGITAL
DOCUMENTATION
Using the STUI camera function, take a
photo clearly showing the temperature
readings on BOTH thermometers for the
front vents.
Upload the photo to STUI.
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
4.
DIGITAL
DOCUMENTATION
L H SIDE
Using the STUI camera function, take a
photo clearly showing the temperature
readings on BOTH thermometers for the
rear vents with a note describing “LH” or
“RH” side.
Upload the photo to STUI.
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
RH SIDE
TSB #: 26-HA-002G
Page 10 of 12
SUBJECT:
5.
REDUCED HEATER PERFORMANCE
•
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
If the temperature difference between the vents in BOTH locations – front center and
rear/3rd row – is less than 18°F, then use OP Code 40D158R1 to finish this inspection
procedure. The service procedure is now complete.
If the temperature difference between the front center vents is 18°F or higher, then
proceed to step 6 to replace the front heater core.
If the temperature difference between the rear vents is 18°F or higher, then proceed to
step 8 to replace the rear heater core.
•
•
i
Information
If the temperature difference between the vents in BOTH locations (front center and rear) is
18°F or higher, then BOTH front and rear heater cores must be replaced.
6.
Replace the front heater core (E).
Refer to the shop manual:
• Heating, Ventilation and Air
Conditioning > Heater > Heater Core >
Repair procedures
E
7.
DIGITAL
DOCUMENTATION
FRONT HEATER CORE
NEW
Using the STUI camera function, take a
clear photo of the OLD front heater core
removed next to the NEW heater core on
top of the box with the “QQH” label
showing and a note designating “Front”.
Upload the photo to STUI.
OLD
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
•
If the rear heater core is to be replaced,
proceed to step 8.
•
If only the front heater core needs
replacing, proceed to step 10.
TSB #: 26-HA-002G
Page 11 of 12
SUBJECT:
8.
REDUCED HEATER PERFORMANCE
– TEMPERATURE CHECK & HEATER CORE REPLACEMENT
Replace the rear heater core (F).
F
Refer to the shop manual:
• Heating, Ventilation and Air
Conditioning > Rear Air Conditioner >
Rear Heater Core > Repair Procedures
i
Information
To prevent coolant spillage inside the
cabin when removing the rear heater
core, place an absorbent material in
the surrounding area. Discard
absorbent material appropriately after
repairs are completed.
9.
DIGITAL
DOCUMENTATION
REAR HEATER CORE
Using the STUI camera function, take a
clear photo of the OLD rear heater core
removed next to the NEW heater core on
top of the box with the “QQH” label
showing and a note designating “Rear”.
NEW
Upload the photo to STUI.
NOTE: If the STUI camera function is
NOT used, write the last 6 digits of the
VIN and date of repair on a piece of
paper to include in the photo.
10.
Reinstall all components in reverse order of
the removal process
11.
Perform air bleeding of the coolant.
OLD
Refer to the shop manual:
• Engine Mechanical System > Cooling
System > Coolant > Repair procedures
12.
Start the engine and confirm proper vehicle
operation.
TSB #: 26-HA-002G
Page 12 of 12
- Formulated to replace the OEM fluid in Asian make vehicles...
- 5 year/150, 000 mile . Silicate-free, long-life, phosphate...
- The long life formula provides protection for all cooling...
- Meets the following OEM and industry specifications: JIS K...
- Note: Please check the vehicle specification before...
If the PDF is very large, it may not load in the preview below.
Some older TSBs had multiple PDFs — visit the NHTSA Website to view all PDFs.
If the TSB PDF does not show, download or view it on the NHTSA Website.
Click on the (+) Plus Sign
Then Click on Associated Document(s)
Search NHTSA Database for Recalls
Search NHTSA Database for Vehicle Investigations
View Latest Vehicle Investigations
Search NHTSA Database for Vehicle Complaints
View Latest Vehicle Complaints
TSB/Document ID: 26-HA-002G TSB
Replacement Service Bulletin Number:
MFR Communication Date: 2026-06-10
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
- [Notice] When you receive a used device, it may be a customer return resold by Amazon without inspection. You can exchange it for a new one through Amazon. As this situation is unavoidable, we sincerely apologize. For any issues, contacting us via Amazon's "Messages" is the best way. THINKSCAN 689BT Bidirectional Scan Tool Can Be Used Immediately After It is Turned On, Without Complicated Registration Process, Which is More Convenient & Quick.
- Full Bi-Directional Control & 3000+ Active Tests: Take control and test components like actuators, fuel injectors, relays, and cooling fans in real time. You’ll quickly see if the problem is in the part itself or the control module — saving you hours of guesswork and frustrating trial-and-error.
- Advanced ECU Coding Capabilities: Handle module matching and hidden feature activation with confidence. When you replace an ECU or want to customize settings, this obd2 scanner diagnostic bi directional tool gives you the professional-level capabilities you need without the dealership price tag.
- 34+ Useful Reset and Maintenance Functions: Complete everyday service tasks smoothly with a wide range of helpful reset and maintenance functions. Whether you’re keeping up with regular upkeep or tackling a specific job, this scanner makes maintenance simpler and less stressful for both DIYers and pros.
- Comprehensive Full System Diagnostics: Diagnose every major system — Engine, Transmission, ABS, SRS, TPMS, and more — all in one place. Finally stop wondering if you’re missing something important; get the full picture and clear codes with ease.
- Top Reasons to Choose the D7S OBD2 Scanner: XTOOL D7S car scan tool, an upgrade of XTOOL D7, offers comprehensive features for automotive technicians, workshops, and DIY enthusiasts 1. Upgraded Hardware: 2+64GB memory, rear camera, intuitive interface, foldable bracket 2. Complete Diagnostics: FCA
Autoauth, OE-level all system scan, 39+ maintenance services, 4K+ bidirectional, CANFD/DoIP protocol 3. Advanced Capabilities: ECU c0ding, PMI functions 4. Wide Compatibility: Support 10,000+ models, covering 99% vehicle brands 5. Multi-language: Available in 22+ languages, No IP Restrictions 6. 3-Year Updates: Save 300 bucks on software updates for the latest features and optimizations - 2026 Upgraded D7S Car Scanner Features: The newly 2026 D7S V2.0 scanner for car brings exciting features for advanced vehicle diagnostics and enhanced user experience 1. FCA AutoAuth: Now supports FCA SGW module for Chrysler, for Jeep, for Dodge (2018+), for Fiat (2017+), enabling faster vehicle communication without gateway restrictions 2. PMI (Offline ECU Pr0gramming): Allows for Ford, for Lincoln, and for Mazda ECU pr0gramming for new modules 3. Optimized Diagnostic Report 2.0: Personalized reports with logos and customer info for auto shops. Note: Compatibility varies by cars, please check before order
- 39+ Services/Resets/Adaptations/Relearns/Calibrations: XTOOL D7S full system car scanner diagnostic tool tackles 99% of common car issues through its 36+ special functions, including Oil Reset, EPB, SAS, BMS, Throttle Reset, Injector C0ding, ABS Bleed, TPMS Reset, Power Balance, etc and also covers specific-vehicle functions like Crank Sensor Relearn, ABS Initialization, Cylinder Power Balance, Fuel Trim Reset, Idle Relearn etc. This car diagnostic scanner enhances efficiency, making repairs and maintenance hassle-free. Tip: DO NOT for All vehicles, please check compatibility first
- Cost-effective ECU C0ding Scan Tool for Specific Brands: Enhance your vehicle's performance with XTOOL D7S! This obd2 scanner all systems bidirectional offers advanced capabilities at an affordable price, supports online for BMW, for Benz and offline for BENZ, for MIT, along with PMI functions for Ford, for Mazda, and for Lincoln. Ideal for technicians and DIY enthusiasts, this automotive scanner diagnostic tool optimizes vehicle performance and enhances the driving experience. Note: Not for all cars and modules, please send car VIN to check the compatibility before purchase
- OE All System Diagnostic & 8 Pids Graphing: XTOOL D7S is a comprehensive all system bi directional obd2 scanner that delivers dealer-level diagnostics, completely controlling over your vehicle’s performance and health. This automotive scan tool can read and clear DTCs, view live data and ECU information, retrieve freeze frames, and perform active tests and full obd2 functions. This bi-directional scan tool can can identify your vehicle's make, model, and year information with just one click and show up to 8 PIDs live data with options for CSV viewing, playback, and recording for in-depth analysis. It is easy-to-use for both professionals and beginners, helping pinpoint issues efficiently
- 【✅Compared to BOSSCOMM IF742, IF745 Offers Full-System Diagnostics】The BOSSCOMM IF745 car diagnostic scanner is an upgraded model of IF742. In addition to supporting all OBD2 Code Reader functions and 6 reset options (ABS/EPB/SAS/BMS/Oil/Throttle), it expands diagnostics from 4 systems (Check Engine/ABS/SRS/Transmission) to vehicle All systems, including Steering, Suspension, and Body Electronics. This provides deeper, more comprehensive diagnostic capabilities.
- 【✨10 OBD2 Functions】The BOSSCOMM IF745 scan tool’s DTC Lookup instantly translates fault codes into user-friendly explanations, its I/M Readiness feature streamlines emissions testing with a single tap, and Freeze Frame lets you pinpoint the exact moment of a fault for in-depth root-cause diagnosis. Combined with a live data dashboard and advanced diagnostics (O2S, OBMon, EVAP), it delivers comprehensive insights for confident troubleshooting.
- 【✨Deep Diagnostics for All Vehicle System Modules】Beyond code reading/clearing and ECU information retrieval, our all-in-one data stream feature lets you inspect all current fault codes and their locations across the vehicle’s systems. This vehicle code reader helps you turn off dashboard warning lights and perform a comprehensive self-check of your car at home—no more back-and-forth trips to the repair shop or hefty inspection fees.
- 【✨6 Essential Resets: ABS Bleeding, Oil, EPB, SAS, Throttle, BMS】The BOSSCOMM IF745 obd2 scanner diagnostic tool swiftly purges air from brake lines to restore braking sensitivity, fine-tunes maintenance cycles to eliminate false alerts, resolves parking brake issues with one-click control, recalibrates steering sensors for stability, optimizes engine idling/acceleration for smoother performance, and deeply resets battery systems to extend lifespan and range via precise parameter adjustments.❗NOTE: Does NOT support bidirectional control, coding, or programming.
- 【✨10,000+ Car Models, AutoVIN, 13 Languages】The BOSSCOMM IF745 vehicle scanner diagnostic tool covers 73+ global car brands and offers support in 13 languages, making it perfect for DIYers, auto mechanics, or as a thoughtful gift. With a single-click AutoVIN feature, it instantly retrieves vehicle serial numbers, streamlining diagnostics for users globally. This adaptable tool balances user-friendliness with precision, catering to both personal and professional requirements.✅Unsure about compatibility? Compatibility will vary on vehicles' model and year, pls reach us via 📧 [email protected] 📧 before purchase.
This product presentation was made with AAWP plugin.