2021 Hyundai Tucson ECU Software Update for Emissions

Hyundai Motor America (HMA) has re-launched Service Campaign 9C2 to address a potential issue with elevated engine-out emissions in certain vehicles equipped with Theta II engines. This campaign specifically targets the Engine Control Module (ECM) with a software update. Owners of affected vehicles, including the 2021 Hyundai Tucson, should be aware of this important service action.

This service campaign is detailed in Technical Service Bulletin (TSB) 26-01-013H-1, which provides comprehensive instructions for dealerships to perform the necessary software update. The bulletin was posted on March 5, 2026, and is crucial for ensuring vehicles meet emissions standards and operate optimally.

Why This Update Is Necessary

Certain Hyundai Santa Fe, Santa Fe Sport, Sonata, and Tucson vehicles equipped with Theta II engines may exhibit elevated engine-out emissions. This condition can impact the vehicle's environmental performance and potentially its long-term reliability. The Hyundai Tucson emissions update is designed to recalibrate the ECM to mitigate these elevated emissions.

The Fix: ECU Software Update

The primary remedy for the elevated engine-out emissions is an Engine Control Module (ECM) software update. This update is identified as software event 1383 and involves specific procedures using the Global Diagnostic System (GDS). The update also includes associated Warranty, ROM ID, and Manual Mode Password information for technicians.

Technical Service Bulletin (TSB) 26-01-013H-1 outlines the precise steps for updating the ECM software. This ensures that the vehicle's engine management system is properly calibrated to reduce engine-out emissions. The Hyundai Tucson emissions update is a critical step to maintain compliance and performance.

Important Notes for Owners

After the software update is performed, an Emissions Label will be required for all vehicles. Additionally, a Vehicle Emission - Proof of Correction Card may be necessary, depending on applicable state regulations. Your Hyundai dealer will provide these documents as part of the service procedure.

What Owners Should Do

If you own a 2021 Hyundai Tucson or any of the other models mentioned, it is recommended to contact your authorized Hyundai dealership. They can confirm your vehicle's eligibility for Service Campaign 9C2 by checking your VIN. Once eligibility is confirmed, the dealership will follow the procedures detailed in TSB 26-01-013H-1 to update the ECM software. This Hyundai Tucson emissions update will be performed free of charge under the service campaign.

Superseded Bulletins and Documents

Technical Service Bulletin (TSB) 26-01-013H-1 supersedes the existing TSB 26-01-013H. This update adds the 2015 model year Sonata (LFA) and new software event information. Furthermore, the dealer notification for this campaign also supersedes an existing document, ensuring that dealerships have the most current information for this service action.

Source: NHTSA ID 11029941