Terms of service

Last Updated: November 11, 2026

Welcome to 4J Tuning ("Company," "we," "us," or "our"). These Terms and Conditions ("Terms") govern access to and use of our website, https://4jtuning.com, and the purchase, licensing, delivery, and use of our products and services.

4J Tuning provides automotive calibration solutions, ECU/TCU tuning files, calibration definitions, proprietary software, diagnostic utilities, and related automotive hardware.

By accessing our website, placing an order, downloading a product, activating a software license, or using our services, you agree to these Terms to the extent permitted by applicable law.

If you do not agree, please refrain from purchasing or using our products and services.

1. Eligibility and Authorized Use

To purchase or use our products and services, you must:

  • Be at least 18 years of age or the age of legal majority in your jurisdiction.

  • Provide accurate and complete purchase information.

  • Be the legal owner of the vehicle or have authorization from its owner to perform the requested services.

  • Possess the necessary knowledge, equipment, and authorization to perform ECU/TCU programming or calibration modifications.

  • Comply with all applicable federal, state, and local laws.

We reserve the right to refuse or cancel orders where we reasonably suspect fraudulent activity, unauthorized access, unlawful use, or violations of these Terms, subject to applicable consumer protection laws.

2. Legal Compliance and Vehicle Modifications

4J Tuning provides automotive calibration products and services for applications permitted by applicable law.

Certain products may be intended for specialized motorsport, competition, research, diagnostic, or off-highway applications. However, labeling a product for off-road or competition use does not automatically make an otherwise prohibited vehicle modification legal.

Customers are responsible for determining whether their intended purchase, installation, and use comply with applicable requirements, including:

  • Federal, state, and local emissions regulations

  • Environmental protection requirements

  • Vehicle registration and inspection requirements

  • Road safety and transportation laws

  • Applicable motorsport and competition regulations

4J Tuning does not authorize or endorse unlawful emissions tampering, the illegal disabling of emissions control systems, or the installation or use of prohibited defeat devices.

We reserve the right to decline requests for products or services that would violate applicable laws.

Customers must not use our products to circumvent legal requirements. No disclaimer in these Terms should be interpreted as permission to perform otherwise unlawful modifications.

3. Digital Products and Calibration Files

4J Tuning offers digital products that may include:

  • ECM and TCM calibration files

  • Custom tuning and performance calibration files

  • XDF and A2L calibration definition files

  • ECU/TCU map packs and definition resources

  • Digital conversion and calibration utilities

  • Software applications and license keys

  • Other downloadable automotive calibration resources

Digital products are generally non-refundable once delivered, made accessible for download, or once custom development has begun, subject to our Refund & Return Policy and applicable law.

By purchasing a digital product, you acknowledge that:

  • Digital files can be downloaded, copied, and retained after delivery.

  • Compatibility requirements may vary depending on ECU/TCU hardware, operating system, software version, and flashing equipment.

  • Purchasing an incorrect or incompatible file does not automatically qualify an order for a refund.

  • Products must be used in accordance with their intended functions and applicable licensing terms.

We will make reasonable efforts to correct verified errors attributable to 4J Tuning.

4. Customer-Provided Files and Vehicle Information

Customers requesting calibration services may be required to provide original ECU/TCU files, software identifiers, VIN information, or vehicle specifications.

By submitting these materials, you represent that:

  • You own the submitted materials or have the necessary authorization to provide and use them.

  • You are authorized to request the modifications or services involved.

  • The information supplied is accurate and complete to the best of your knowledge.

  • Your submission and requested use do not violate applicable laws or third-party rights.

Customers are responsible for verifying vehicle specifications, modifications, hardware compatibility, and operating system information.

4J Tuning is not responsible for errors resulting solely from inaccurate or incomplete customer-provided information.

Additional charges may apply when customer errors require substantial rework after custom calibration development has begun. Any additional charges will be disclosed before the additional paid work proceeds.

Errors directly attributable to 4J Tuning will be corrected at no additional charge, subject to the remedies described in our Refund & Return Policy.

5. Intellectual Property and Ownership

All proprietary software, original calibration definitions, custom-developed content, application interfaces, algorithms, documentation, branding, and other intellectual property created or owned by 4J Tuning remain the exclusive property of 4J Tuning or its applicable licensors.

Purchasing a digital product grants a limited right to use that product under the applicable license. It does not transfer ownership of the underlying intellectual property.

Unless expressly authorized in writing, customers may not:

  • Resell, redistribute, sublicense, or publicly share purchased digital files.

  • Upload purchased XDF, A2L, map packs, or proprietary software to public repositories, forums, or file-sharing services.

  • Repackage or commercially distribute proprietary 4J Tuning products as their own.

  • Remove or alter copyright notices, licensing information, or ownership identifiers.

  • Reproduce or distribute substantial portions of our proprietary software or definitions without permission.

Legitimate calibration work is permitted. Subject to applicable laws and product-specific licensing restrictions, purchasers may use licensed calibration definitions and tools to develop vehicle calibrations for themselves or their customers.

This permission does not authorize redistribution of the underlying purchased definitions, software, or proprietary source materials.

Ownership of customer-submitted files and third-party intellectual property remains with their respective rights holders. These Terms do not claim ownership of customer-provided materials solely because they were uploaded to our website.

6. Software Licensing and Activation

Certain 4J Tuning applications, including DTC Toolbox and other proprietary utilities, require a valid software license.

Depending on the product and edition, licenses may be offered as lifetime, annual, subscription-based, or otherwise time-limited licenses.

Unless a product-specific license states otherwise:

  • Each license is issued to the original purchaser or authorized license holder.

  • Licenses may be associated with a particular user account, computer, or hardware identifier.

  • Unauthorized license sharing, duplication, resale, or transfer is prohibited.

  • License activation and verification may require an internet connection.

  • Hardware changes, operating system changes, or computer replacement may require license reactivation.

  • License transfers and additional activations are subject to the applicable product's published licensing terms.

A lifetime license refers to a one-time license for the specified software product or edition, subject to its applicable terms. It does not necessarily include unlimited future feature upgrades, perpetual cloud service availability, or unlimited hardware transfers unless expressly advertised.

Annual and time-limited licenses provide access for the purchased license period.

We may suspend or revoke licenses when there is substantiated evidence of fraud, unauthorized distribution, license circumvention, or material violations of these Terms, subject to applicable law and any required notice or opportunity to resolve the issue.

Legitimately purchased licenses will not be revoked arbitrarily.

7. Software Protection and Unauthorized Access

4J Tuning software may incorporate proprietary algorithms, licensing systems, activation controls, and security mechanisms designed to protect our intellectual property.

Except where expressly permitted by applicable law or written authorization, users may not:

  • Reverse engineer, decompile, or disassemble proprietary software to obtain protected source code or algorithms.

  • Bypass, disable, or manipulate software licensing and activation systems.

  • Modify application binaries to remove licensing restrictions.

  • Distribute modified or unauthorized copies of our software.

  • Use automated or unauthorized methods to compromise licensing infrastructure.

  • Access restricted software functions without the appropriate license.

We reserve the right to investigate suspected licensing abuse and take proportionate protective measures, including restricting unauthorized access and pursuing available legal remedies.

Nothing in these Terms restricts rights to interoperability, security research, or other activities that cannot lawfully be prohibited.

8. Software Updates, Compatibility, and Support

4J Tuning may release software updates to improve compatibility, functionality, security, and supported controller coverage.

We do not guarantee:

  • Compatibility with every ECU/TCU variant or software revision.

  • Compatibility with all future operating systems, flashing tools, or third-party applications.

  • That every software feature will remain unchanged indefinitely.

  • That every requested vehicle or controller will receive future support.

Software functionality and supported platforms are defined by the product descriptions and documentation applicable at the time of purchase.

We may modify or discontinue features when reasonably necessary for security, technical compatibility, legal compliance, or product maintenance.

Material changes affecting existing paid entitlements will be handled in accordance with applicable licensing commitments and consumer protection laws.

Technical support is available through support@4jtuning.com.

9. Subscriptions and Renewals

Certain software products may be offered through recurring subscriptions or fixed-term licenses.

The billing period, renewal terms, price, and cancellation procedures will be disclosed before purchase.

Where automatic renewal is offered:

  • Customers must be informed of recurring charges before subscribing.

  • Recurring billing requires the customer's affirmative authorization.

  • Customers may cancel future renewals using the available account or billing management method or by contacting support.

  • Cancellation prevents future charges after it takes effect but does not automatically entitle the customer to a refund for the current billing period.

  • Access generally continues through the paid subscription period unless otherwise disclosed or legally required.

Fixed-term licenses that do not automatically renew expire at the end of their purchased term unless renewed by the customer.

Subscription refunds and cancellation remedies are governed by our Refund & Return Policy and applicable law.

10. Product Compatibility and Customer Responsibilities

Customers must verify that purchased products are appropriate for their vehicle, controller, software version, and intended application.

Before purchasing or using a product, customers should confirm:

  • Vehicle year, make, model, and engine specifications

  • ECU/TCU hardware and software identifiers

  • Operating system and calibration compatibility

  • Supported flashing equipment and communication interfaces

  • Availability of appropriate backup and recovery procedures

Customers are responsible for preserving original calibration files and following the instructions provided with purchased products.

Improper flashing, interrupted programming, incompatible files, or unauthorized modifications may result in vehicle malfunctions or controller damage.

4J Tuning is not responsible for losses caused by misuse, unauthorized alterations, or incompatible equipment outside our reasonable control, except where liability cannot legally be excluded.

Customers are encouraged to use qualified professionals when performing advanced vehicle programming procedures.

11. Performance, Reliability, and Vehicle Warranty Disclaimer

Automotive calibration changes can affect engine performance, transmission operation, fuel consumption, component wear, emissions, and overall vehicle reliability.

Actual results depend on vehicle condition, mechanical configuration, modifications, environmental conditions, and the quality of installation and calibration.

Unless expressly stated in a product description, 4J Tuning does not guarantee:

  • Specific horsepower or torque increases

  • Fuel economy improvements

  • Particular acceleration or performance results

  • Compatibility with every vehicle configuration

  • Preservation of manufacturer warranties

  • Freedom from all mechanical or electronic failures

Customers acknowledge that vehicle modifications may affect manufacturer warranty coverage, inspection eligibility, or vehicle operation.

We recommend ensuring that vehicles are mechanically sound before installing calibration modifications.

12. Third-Party Products and Services

Some 4J Tuning products may be designed for use with third-party hardware, software, or flashing platforms.

References to third-party products are provided for identification and compatibility purposes.

Unless explicitly stated, 4J Tuning is not affiliated with, sponsored by, or endorsed by the manufacturers of those products.

Third-party products may be subject to separate licenses, warranties, activation requirements, and usage restrictions.

We are not responsible for independent changes made by third-party providers that affect compatibility or service availability.

13. Physical Products and Hardware

Physical products, including tuning devices, interfaces, and related accessories, may be subject to manufacturer registration, activation, or vehicle-association restrictions.

Customers should verify product compatibility before purchase.

Returns, cancellations, defective hardware claims, and warranty matters are governed by our published Refund & Return Policy and any applicable manufacturer warranty.

Some activated, registered, or vehicle-linked products may be ineligible for discretionary returns.

Nothing in these Terms limits statutory remedies for defective, incorrectly supplied, or misrepresented goods.

14. Pricing, Payments, and Order Acceptance

Unless otherwise stated, all prices displayed on our website are in United States Dollars (USD).

Payment must be successfully completed before products are delivered or services begin, unless another arrangement is expressly agreed upon.

We accept payment through the payment methods made available at checkout.

We reserve the right to correct obvious pricing or listing errors before accepting an order.

If an order cannot be fulfilled, we will notify the customer and issue an appropriate refund for any payment collected.

Applicable taxes, shipping charges, and other required fees will be displayed before order confirmation where required by law.

An order confirmation acknowledges receipt of an order and does not necessarily guarantee acceptance of a transaction that is fraudulent, unlawful, or impossible to fulfill.

15. Product Delivery and Processing Times

Digital products may be delivered through email, direct download, customer accounts, license activation, or another electronic distribution method.

Instant-download products are generally made available after successful payment processing.

Custom tuning and calibration services require additional preparation.

Custom calibration orders are generally processed within 1–3 business days, depending on complexity, workload, and whether all required information has been received. This is an estimate, not a guaranteed deadline unless expressly stated.

Customers are responsible for providing a valid email address and reviewing delivery instructions.

If a purchased product is not received, customers should contact support@4jtuning.com.

Delivery failures attributable to 4J Tuning will be investigated and resolved through redelivery, correction, or another appropriate remedy.

16. Refunds, Returns, and Order Disputes

Refund eligibility, returns, cancellations, and corrections are governed by our published Refund & Return Policy, which forms part of these Terms.

Digital products and custom services are subject to the restrictions described in that policy, including applicable exceptions for verified defects, delivery failures, and legally required remedies.

Customers experiencing purchase or product issues are encouraged to contact our support team before initiating a payment dispute so we have an opportunity to investigate and resolve the concern.

Nothing in these Terms limits a customer's lawful rights to contact their payment provider, challenge unauthorized transactions, or exercise statutory consumer protections.

17. Limited Warranties and Disclaimer

To the maximum extent permitted by applicable law, software and digital calibration products are provided without warranties beyond those expressly stated in their product descriptions, applicable license agreements, or required by law.

We do not warrant uninterrupted software availability, universal compatibility, or that all products will satisfy every customer's specific requirements.

Where a verified defect or failure to provide the product as described occurs, we will offer a remedy consistent with our Refund & Return Policy and applicable law.

Nothing in these Terms excludes warranties or consumer rights that cannot lawfully be disclaimed.

18. Limitation of Liability

To the maximum extent permitted by applicable law, 4J Tuning shall not be liable for indirect, incidental, special, or consequential damages arising from the use or misuse of our products or services, including lost business opportunities, lost profits, or downtime, where such exclusions are legally permitted.

We are not responsible for damage resulting solely from:

  • Improper or unauthorized installation

  • Incorrect or incompatible flashing procedures

  • Customer modifications to supplied files

  • Failure to follow provided instructions

  • Inaccurate customer-submitted information

  • Third-party equipment failures outside our control

For claims where a contractual liability limitation is legally permitted, our aggregate liability relating to a purchased product or service will generally not exceed the amount paid to 4J Tuning for the specific product or service giving rise to the claim.

These limitations do not apply where prohibited by law, including liability or remedies that cannot legally be excluded or restricted.

19. Customer-Submitted Content and Privacy

Customers may submit calibration files, vehicle information, technical records, or other materials required for services or technical support.

By submitting these materials, customers grant 4J Tuning a limited right to access, process, store, and modify them as reasonably necessary to provide purchased services, deliver support, investigate technical issues, and fulfill legal obligations.

We do not acquire ownership of customer-provided materials solely through their submission.

Personal information is handled in accordance with our published Privacy Policy.

Customers should avoid submitting information unrelated to the requested service.

20. Account Security and Service Restrictions

Customers are responsible for maintaining the security of their account credentials and software licenses.

Unauthorized account access, fraudulent payment activity, attempts to compromise our systems, or material violations of these Terms may result in account restrictions or suspension.

Where reasonably practicable, we will provide notice and an opportunity to resolve account or licensing issues before permanent termination, except where immediate action is necessary to prevent fraud, security threats, or unlawful activity.

Any cancellation or termination will remain subject to applicable refund rights and licensing commitments.

21. Changes to Products and Terms

4J Tuning reserves the right to update these Terms to reflect changes in business operations, products, technology, or legal requirements.

Updated Terms will be published on our website with a revised effective or last-updated date.

Material changes affecting existing purchases or ongoing subscriptions will be communicated as required by applicable law.

Changes will generally apply prospectively and will not retroactively eliminate rights already established under a completed purchase or existing agreement.

Continued use of services after a validly communicated update may constitute acceptance where permitted by law.

22. Dispute Resolution

We aim to resolve customer concerns through direct communication and reasonable investigation.

Customers are encouraged to contact support@4jtuning.com with their order number and a description of the issue.

We will review disputes in good faith and work toward an appropriate resolution.

Nothing in these Terms prevents either party from exercising legal rights or pursuing remedies available under applicable law.

If any provision of these Terms is determined to be invalid or unenforceable, the remaining provisions will continue in effect to the extent legally permitted.

23. Contact Information

For questions regarding these Terms, software licensing, digital products, calibration services, or purchases, please contact:

4J Tuning

Website: https://4jtuning.com

Email: support@4jtuning.com

By purchasing, downloading, activating, or using 4J Tuning products or services, you acknowledge that you have reviewed these Terms and agree to the provisions applicable to your transaction, subject to applicable law.