Mechanic Wiki: How to Add a Key to a GAC Trumpchi GS4 (2015

Step-by-step guide to program a spare key for a first-generation GAC Trumpchi GS4 (2015–2018) using a LAUNCH X431 diagnostic tool. Includes prerequisites, troubleshooting, and FAQs.

Last Updated: June 16, 2026

How to Add a Key to a GAC Trumpchi GS4 First Generation (2015–2018) with LAUNCH X431

Quick Answer: If you own a first-generation GAC Trumpchi GS4 (2015–2018) and need a spare key, you can program a new remote and transponder chip yourself using a LAUNCH X431 diagnostic tool. The process requires one working master key, the X431 tablet, and a compatible blank key. Connect the tool, navigate to the Immobilizer menu, select "Add Key," follow the on-screen prompts, and test both keys. If you’ve lost all keys, professional help is needed because this generation typically requires a master key present for the X431 to complete the programming.

Prerequisites & Preparation

Before you dive into the programming procedure, a little groundwork saves time and frustration. Here’s what you need and what to understand about your vehicle’s key system.

What You Need Before You Start

LAUNCH X431 diagnostic tool – Any version that supports GAC Trumpchi GS4 (Pad, Pro, V, or equivalent) will work. Make sure the software is up to date.
One working master key – This is mandatory for the "Add Key" function. Without it, you’re looking at a dealer or locksmith visit.
Blank transponder key – Must be compatible with the GS4. Typically, these use an ID46 or 4D-60 chip. Smart key blanks with 315 MHz or 433 MHz frequency are common (check your original key for the frequency). High-quality blanks from brands like Xhorse or Ili tend to have fewer compatibility issues.
Vehicle ignition access – You’ll need to turn the key to the ON position repeatedly.
Stable 12V battery – Low battery voltage is a common cause of programming failures. If your battery is weak, connect a charger before starting.
Stable internet connection – The X431 downloads necessary software and data in real time, so a Wi-Fi or cellular connection is essential.

Understanding Your Key System

Smart Key vs. Standard Remote: The GS4 uses a smart key fob with both remote functions (lock/unlock) and a transponder chip that enables the engine to start. The programming process handles both parts, but they are tackled in separate steps.

Key Generation Difference: The first-generation GS4 (2015–2018) runs an older immobilizer system compared to later models. This means the procedure is more manual—you’ll need to follow each prompt carefully, and there is no fully automatic "one-button" solution.

Step-by-Step Guide: Adding a Key with LAUNCH X431

Follow these instructions in order. Each step builds on the previous one, so skipping ahead can cause errors.

Step 1: Connect and Access the Vehicle

Plug the LAUNCH X431 into the OBD-II port located under the driver’s side dashboard.
Turn the ignition ON using the working master key (do not start the engine).
On the X431 home screen, select GAC.
Choose Trumpchi GS4 and then select the model year range 2015–2018.

The tool will automatically detect your vehicle and load the relevant software.

Step 2: Navigate to Immobilizer / Key Programming

Tap Diagnostics.
Look for Immobilizer or Anti-Theft system (it may be under a "Security" menu in some X431 versions).
Select Special Functions (sometimes labeled "Action Test" or "Service").

The X431 will now establish communication with the immobilizer control unit.

Step 3: Select "Add Key" – Not "Erase All Keys"

Critical Warning: Do not select "Erase All Keys" unless you have no working keys and understand you will need a dealer PIN code. The X431 may prompt you for a PIN number. For an "Add Key" function on this GS4 generation, the tool often generates the PIN automatically based on the VIN or other vehicle data. If not, you may need to obtain the PIN from GAC or a locksmith.

Confirm that you see Add Key or Learn Key as an option.
Select it and follow any confirmation prompts.

Step 4: Enter Key Learning Mode

The X431 will instruct you to turn the ignition OFF and then back ON using the master key.
Now, insert the new blank key into the ignition and turn it to the ON position. (If you have a smart key, place it in the backup slot inside the center console or near the steering column—check your owner’s manual for the exact location.)
Wait for the "Learn New Key" prompt to appear on the X431 screen.

Do not rush this step. The immobilizer system needs a moment to recognize the new key's presence.

Step 5: Program the Transponder Chip

Press Confirm on the X431.
The tool will communicate with the immobilizer and program the chip. The security light on the dashboard may flash rapidly or stay solid during this process.
Wait for the "Programming Successful" message.
Turn the ignition OFF and remove the new key.

If you receive a failure message at this point, check the troubleshooting section below.

Step 6: Program the Remote Functions

The X431 may automatically move to the remote coding step after transponder programming. If not:

From the Immobilizer menu, select Remote Programming.
Press the Lock and Unlock buttons on the new key fob simultaneously for 3 seconds.
Release the buttons. The X431 should confirm that the remote is coded.

Test the remote buttons immediately—press lock and unlock to see if the doors respond.

Step 7: Verify All Keys Work

Test the old master key to ensure it still starts the vehicle.
Test the new key to ensure it starts the engine AND all remote buttons function.
Clear any trouble codes from the immobilizer system using the X431’s Clear Codes function. This prevents false security warnings later.

Congratulations—you’ve successfully added a key!

Troubleshooting Common Issues

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

"Programming Failed" Error

Possible Causes: Weak battery, poor X431 connection, or an incompatible blank key.
Fix: Ensure the vehicle battery is fully charged (keep a charger on). Reconnect the X431. If the problem persists, try a different brand of blank key. The GS4 is known to be picky with cheap aftermarket blanks—stick with brands like Ili or JCI.

X431 Cannot Find the Immobilizer System

Possible Cause: Outdated software on the X431.
Fix: Before starting, update the X431 software via Wi-Fi. Also verify you selected the correct model year (2015–2018). Some early 2015 models may have slightly different immobilizer hardware.

New Key Starts the Engine but Remote Doesn’t Work

Possible Cause: The remote function was not coded properly in Step 6.
Fix: Repeat the remote programming step. This time, enter the Body Control Module (BCM) from the X431 diagnostics menu and look for Remote Key Coding function. Follow the on-screen prompts to program the lock/unlock buttons again.

Dash Security Light Stays On

Possible Cause: The transponder chip was not fully "learned" into the ECU.
Fix: The previous attempt may have only programmed the remote, not the chip. Run the Immobilizer – Learn Key sequence again from the beginning. Make sure the new key is in the ignition before confirming.

When to Call a Professional

Most DIY key programming goes smoothly, but there are situations where it’s smarter to hand the job to a specialist.

Zero Working Keys: If you’ve lost all keys, the X431 (for this generation) typically requires a factory PIN code from GAC. You cannot simply select "Erase All Keys" without that PIN. A locksmith with a dedicated key programmer (like Xhorse or Autel IM608) can read the PIN and program a new key faster—and often cheaper—than a dealer.
Tool Fails to Connect Mid-Programming: If the X431 loses connection while writing data to the immobilizer, you risk corrupting the system. Recovery requires specialized equipment. If this happens, stop immediately and call a professional.
You’re Not Comfortable with Electronics: If you’re unsure about any step, it’s better to pay a small fee than to risk a stranded vehicle.

Frequently Asked Questions

Can I use the LAUNCH X431 to program a key if I lost all keys for my 2016 Trumpchi GS4?

Generally, no for this first-generation model. The "Add Key" function requires a master key in the ignition. "Erase All Keys" exists, but the X431 may not automatically retrieve the 4-digit PIN code required by the GAC ECU. A dealer or locksmith with a PIN-reading tool is needed to recover access.

What type of blank key do I need for a 2015–2018 Trumpchi GS4?

For the first generation, you need a GAC Trumpchi GS4 Smart Key blank. The chip type is typically ID46 or 4D-60. Look for a key with a 315 MHz or 433 MHz frequency (check your original key). High-quality blanks from Xhorse or Ili work well. Avoid generic unbranded blanks—they often fail during programming.

Is there a manual method to add a key without a diagnostic tool?

No, not for the GS4. Unlike some older Toyota or Honda models where you can jumper certain pins, the GAC Trumpchi requires a diagnostic tool (X431, Autel, or dealer SDD) to enter the immobilizer programming mode. There is no manual bypass for this vehicle.

How long does the Key Programming process take?

The actual programming of the transponder takes about 30 seconds. The entire process, including connecting the tool, waiting for software to load, and testing, takes approximately 15–20 minutes. If you run into troubleshooting, add another 10–15 minutes.

Will programming a new key erase my existing keys?

No, if you select "Add Key" or "Learn Key" , your existing keys remain functional. Only selecting "Erase All Keys" will delete all keys from the ECU. So your working master key will still work after the process.

Can I use a used key from another Trumpchi GS4?

You can, but it must be a virgin key (unused) or a blank key. A used key from another car is already linked to its old ECU and cannot be programmed to your vehicle without being "re-synchronized," which often requires a locksmith with a specialized chip programmer. It is easier and more reliable to buy a new blank key.

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 Key to a GAC Trumpchi GS4 (2015–2018) with LAUNCH X431