Step-by-step guide to program a spare remote key for GAC Trumpchi (GS4, GS8, GA6) using LAUNCH X431. Save $150–$400 with DIY OBD key programming.

Quick Answer

To add a remote key to a GAC Trumpchi using a LAUNCH X431 scanner without dealer access, you need to navigate to the Immobilizer or Key Programming function, select "Add Key" (not "Erase All"), and follow the on-screen prompts after entering security access codes. The process typically takes 10–20 minutes and requires the X431 device, your original keys, and the new blank key. Ensure the X431 has the latest software updates and a stable OBD connection before starting.

Introduction

If you own a GAC Trumpchi (like the popular GS4, GS8, or GA6) and need a spare remote key, you’ve likely faced two options: pay the dealership hundreds of dollars or find a DIY solution. The good news is that professional-grade diagnostic tools like the LAUNCH X431 can handle this task right from your garage — no dealer appointment required.

Why does this matter? Because losing a key or needing a spare shouldn’t mean a trip to the dealership and a hefty bill. With the right equipment and a clear process, you can add a remote key to a GAC Trumpchi yourself, saving time and money. Dealership key programming can cost anywhere from $150 to $400 depending on the model and region. A LAUNCH X431 scanner, by contrast, is a one-time investment that pays for itself after a few uses.

But before you start, you need to confirm compatibility. The LAUNCH X431 supports a wide range of GAC Trumpchi models, including the GS4 (2015–present), GS8 (2017–present), GA6 (2016–present), and many others. However, some newer models may require firmware updates or additional subscriptions. I’ll cover how to verify your specific vehicle below.

Tools and Preparation

Equipment Checklist

Before diving into the programming steps, gather everything you need. Missing any single item can derail the entire process.

LAUNCH X431 device – Recommended models include the X431 V+, X431 Pro, X431 PAD series, or any current-generation scanner with GAC/Trumpchi coverage. Older entry-level models may lack the Immobilizer function.
Blank remote key – This must match your Trumpchi’s frequency (typically 315 MHz or 433 MHz) and transponder chip type (commonly 48-bit crypto or 4C chip). Check the FCC ID on your original key fob or consult a reputable supplier.
Original working key – At least one programmed key is mandatory for the “Add Key” procedure. If you have lost all keys, you will need a locksmith or dealer.
Stable internet connection – The X431 needs to download the latest GAC Immobilizer database and security access codes.

Pre-Programming Checks

A few simple checks will prevent frustration halfway through the procedure.

Verify vehicle battery voltage – Use a multimeter or the X431’s built-in battery test. You need at least 12.6V (engine off). Low voltage can cause communication failures during key programming. If your battery is weak, charge it or run the engine for a few minutes (but keep it off during programming).
Inspect the OBD2 port – It’s usually under the dashboard, driver’s side. Make sure it’s clean and not obstructed by debris or aftermarket accessories.
Update the X431 software – Connect your device to Wi-Fi, open the update center, and install the latest GAC/Trumpchi Immobilizer database. This is critical because vehicle immobilizer logic changes across model years. Never skip this step.

Step-by-Step: Adding a Remote Key via OBD

Now let’s walk through the actual procedure. I’ve performed this on multiple Trumpchi models, and the steps are very similar. Follow them in order, and don’t rush.

Accessing the Immobilizer Function

Connect the LAUNCH X431 to the OBD2 port – Plug it in firmly. Turn the ignition to the ON position (engine off). The scanner should power on automatically.
Select the vehicle brand – On the X431 home screen, choose “GAC” or “Trumpchi” from the brand list. If you see “Trumpchi” as a sub-brand under GAC, select it.
Choose the correct model and year – The scanner will present a menu. For example, “Trumpchi GS4 2018 1.5T.” If you’re unsure, use the VIN auto-detect feature — the X431 can read the VIN and pull up the exact variant.
Navigate to Immobilizer or Anti-Theft System – This is usually found under “System Selection” or “Special Functions.” On most Trumpchi models, it’s labeled “Immobilizer” or “Key Programming.”

If the scanner fails to read the vehicle, double-check the OBD connection and try selecting “Diagnosis” first, then manually enter the VIN.

Entering Security Access

This is the step where many DIYers get stuck. Modern GAC Trumpchi immobilizers require a security access code (sometimes called a PIN or SA code) before they allow key addition. Here’s how to handle it.

Automatic code retrieval – The X431 may fetch the security code automatically from an online server. This works if your scanner subscription includes the necessary data. For example, LAUNCH’s “Cloud” or “Online” immobilizer function often retrieves codes for common models.
Manual code entry – If automatic retrieval fails, you’ll need to enter the code yourself. Where do you get it? Some options:
- Your X431 subscription may offer a “Code Calculation” service for an additional fee (usually $10–$30 per use).
- Third-party services (e.g., auto locksmith forums, key code providers) can supply codes if you provide the VIN.
- Dealership-level login (VCX or J2534 pass-through) is another route, but that defeats the “without dealer access” goal.

Important: If you don’t have the security access code and cannot retrieve it, you will not be able to proceed. Check your X431’s subscription level before starting — the basic package may not include code retrieval for all models.

Key Addition Procedure

Once the security access is granted, the scanner will display a menu with options like “Add Key,” “Erase All Keys,” “Key Replacement,” etc. Choose “Add Key” unless you intend to program a full set of new keys and delete old ones.

Here’s the typical flow:

Insert the original working key – The scanner will ask you to place the original key in the ignition and turn it to ON. Do this and confirm on the screen. The immobilizer will “learn” that this key is authorized.
Follow ignition commands – The scanner may ask you to turn the key OFF, then ON again within a few seconds. This timing must be precise. Pay attention to the on-screen prompts.
Program the new blank key – The scanner will instruct you to remove the original key and insert the new blank key. Turn it to ON. The immobilizer will attempt to write the transponder data. Wait for a confirmation message (usually “Key Learned Successfully” or similar).
Verify all programmed keys – The scanner will prompt you to test each key. Turn the ignition ON with the newly programmed key — the engine should crank (don’t start yet). Then test the remote functions: lock, unlock, trunk, remote start (if equipped).

If you have more than one new key to add, the scanner will usually allow you to repeat steps 2–3 for up to 4 keys (depending on the model).

A word of caution: Never select “Erase All Keys” unless you are prepared to program a full set of keys from scratch. If you erase all keys without having at least two programmed keys ready, you may lock yourself out of the vehicle.

Troubleshooting Common Issues

Even with careful preparation, things can go wrong. Here are the most common problems and how to fix them.

X431 Fails to Connect or Recognize Vehicle

Update firmware and software – This is the number one cause. Go to “System Update” and install any pending GAC/Trumpchi updates.
Try a different OBD2 adapter or cable – If you’re using an extension cable or a Bluetooth adapter, bypass it. Plug the X431 directly into the OBD2 port.
Manually enter VIN – If auto-detect fails, the scanner may allow you to type the 17-character VIN manually. This often forces it to load the correct database.

Security Access Code Not Provided

Check your subscription level – Basic subscriptions may not cover immobilizer functions. Log in to your LAUNCH account and verify. You may need to upgrade to a “Pro” or “Key Programming” pack.
Use backup methods – If the scanner cannot fetch the code, you can purchase a code from a third-party provider. Be cautious: some providers are unreliable. Stick to well-known auto locksmith resources.
Try “Learn Mode” (if supported) – A few GAC Trumpchi models have a “Learn Mode” that bypasses the security code when a certain sequence is performed (e.g., turning ignition on/off rapidly). Check your vehicle’s service manual or online forums. This is rare for modern models.

Key Programming Fails Mid-Process

Ensure the new key is correct – Double-check the transponder chip type. For example, some Trumpchi GS4 models use a 48-bit crypto chip, while others use a simple 4C. The wrong chip will not program. Also verify the remote frequency (315 MHz vs 433 MHz) matches the vehicle.
Minimize interference – Move the vehicle away from other cars, electronic devices, or metal structures. Remove any RFID-blocking key pouches from the keys. Try holding the new key closer to the ignition ring (where the antenna is located).
Try “Key Replacement” instead – If you only have one working key and the scanner fails with “Add Key,” choose “Key Replacement” (or “All Key Lost”) if your subscription supports it. This will program one or two new keys by erasing all old ones (but requires the security code).

Only Some Functions Work (e.g., remote lock but no start)

This indicates the transponder chip was not programmed successfully, even though the remote part worked.

Repeat the programming with extended ignition time – Turn the ignition ON with the new key and leave it for 10 seconds before turning it OFF. This can help the immobilizer finalize the chip learning.
Check if your vehicle requires an antenna booster – Some GAC Trumpchi models have a weak immobilizer antenna. If the new key fails to start, you may need to hold it directly against the start button (for push-to-start models) or wrap a copper wire around the key slot to boost the signal.

Tips for Success

Based on my experience helping technicians and DIYers with LAUNCH X431 key programming, here are a few insider tips that can save you time:

Always have at least two programmed keys before using “Erase All Keys.” If you accidentally erase everything and only have one key, you might be stuck with a non-starting vehicle.
Test all key functions (lock, unlock, trunk, remote start) before closing doors. I’ve seen cases where a key seems to program fine, but then the owner closes the hood and realizes the trunk button doesn’t work. Test everything while you’re still connected.
Write down the security access code once you retrieve it. Store it in a safe place — you’ll need it again if you ever have to reprogram keys. Most X431 scanners will display the code on screen; take a photo or write it down.
Keep the X431 connected until you’ve verified the engine starts. If you disconnect too early, the immobilizer may not fully finalize the key.
For push-to-start Trumpchi models, the procedure is similar but the ignition commands are replaced with “Press Start button without brake” and “Press Start button with brake.” Follow the on-screen prompts carefully.

Frequently Asked Questions (FAQ)

Can I use any blank remote key?
No, it must match your Trumpchi's frequency (typically 315 MHz or 433 MHz) and transponder chip type. Check your original key's FCC ID or consult a dealer.

Do I need dealer authorization or subscription for X431?
Basic immobilizer programming is included in most X431 subscriptions, but security access codes may require additional payment or a dealer-level login.

How many keys can I program in one session?
Usually 2–4 keys depending on model. The scanner will state the maximum allowed.

What if I lose all working keys?
You will likely need dealer assistance or a professional locksmith, as "Add Key" requires at least one existing programmed key for this model.

Will this void my vehicle warranty?
No, OBD programming is a standard diagnostic procedure. However, incorrect use could cause immobilizer issues that require dealer reset.

How long does the process take?
Typically 10–20 minutes, plus preparation time for software updates.

Can I program a key from another manufacturer?
No, only GAC Trumpchi-compatible keys will work. Using incompatible keys can damage the immobilizer module.

Conclusion

Adding a remote key to a GAC Trumpchi using a LAUNCH X431 is a practical, money-saving skill that puts you in control. You avoid dealership wait times and hefty fees while gaining the independence to manage your vehicle’s keys yourself. The key steps are straightforward: prepare your tools, update the scanner, access the immobilizer function, enter the security code, and follow the “Add Key” prompts.

By now you should have a clear roadmap. Just remember: patience is your best tool. If you hit a snag, double-check the basics — battery voltage, key compatibility, and software updates. And if you’re ever in doubt, the LAUNCH X431 has robust online help and community forums.

Have you successfully programmed a key on your Trumpchi? Or do you have additional questions? Drop a comment below — I’d love to hear your experience or help troubleshoot. For more vehicle diagnostics guides, check out our [article on common OBD error codes and how to fix them]. And if you’re in the market for a LAUNCH X431, we have a [full comparison of models and subscription plans] to help you choose the right tool for your needs.

Published: June 16, 2026

About the Author: Erwin Salarda is an Automotive Service Equipment Technician based in the Philippines, specializing in computerized automotive diagnostic equipment such as OBD scanners and wheel alignment systems. Since 2012, he has been actively providing technical support, equipment installation, troubleshooting, after-sales service, and hands-on training for automotive service equipment used by workshops and automotive professionals.

He has received specialized training from international suppliers and manufacturers, including Launch X431 in Shenzhen, China, Lawrence Engineering Company in Guangzhou, China, and 3Excel Wheel Alignment Company in Shenzhen, China. Through these trainings, he developed advanced expertise in automotive diagnostics, calibration, wheel alignment systems, and computerized automotive service technologies.

Erwin Salarda provides professional after-sales support and technical training for automotive diagnostic and wheel alignment equipment, helping clients maximize the performance and proper use of their tools and systems. His experience covers equipment setup, software updates, calibration procedures, troubleshooting, and operational guidance for automotive workshops and service centers.

With more than a decade of experience in the automotive equipment industry, Erwin Salarda continues to support automotive businesses by delivering reliable technical expertise and practical training solutions.

For inquiries and equipment purchases, please visit https://carlifterph.com/

How to Add a Remote Key to a GAC Trumpchi Using LAUNCH X431 (No Dealer)