Mechanic Wiki: How to Program a Geely MK Key Using LAUNCH X431

Learn how to program a Geely MK key with a LAUNCH X431 scanner. Includes PIN retrieval, key programming steps, troubleshooting tips, and FAQs. Works for spare or lost keys.

Published: May 30, 2026

Quick Answer: Programming a Geely MK Key with LAUNCH X431

To program a new or additional key for your Geely MK using a LAUNCH X431 scanner, you must first read the vehicle’s anti-theft PIN code (usually via the immobilizer system) and then perform a key programming procedure. The process typically takes 10–20 minutes and requires a working key (if programming a spare) or the scanner alone (if all keys are lost). Always ensure battery voltage is above 12.5V and the scanner has the latest software.

Understanding Your Geely MK’s Immobilizer System

Every Geely MK comes equipped with an electronic immobilizer system designed to prevent theft. Here’s how it works:

Transponder chip: Inside your key is a small chip that communicates with the vehicle’s Engine Control Unit (ECU) via a ring antenna around the ignition cylinder.
PIN code: A unique 4- or 5-digit code links the key to the ECU. Without this PIN, you cannot program a new key.
Why a PIN is mandatory: The immobilizer checks the chip’s ID against a stored list. If the ID doesn’t match, the ECU cuts fuel and spark. Programming a new key requires telling the ECU to accept the new chip, and that authorization requires the PIN.

Where can you find the PIN? On some Geely MK models, it’s printed on a small plastic tag attached to the key ring or inside the owner’s manual. If you don’t have that, your LAUNCH X431 can retrieve it directly from the immobilizer module — which is the method we focus on here.

Prerequisites & Preparation

Before you begin, gather the following:

A LAUNCH X431 scanner (any current model like X431 V, PAD, Pro, or Pro Mini — as long as it has Geely software installed and updated).
A new blank key with the correct transponder chip. Most Geely MK models use an ID46 or ID48 chip. Check your model year or consult a locksmith to confirm.
A working key (if you only want to add a spare) — not required if you’re starting from scratch with all keys lost.
Stable internet connection to update the scanner software before starting.
A fully charged battery (above 12.5V). Low voltage can cause communication errors during programming.

Vehicle safety: Turn off the ignition, close all doors, and make sure no accessories (lights, radio) are on while you work.

Scanner preparation:

Connect the scanner to Wi-Fi.
Go to the “Software Update” section and install the latest Geely package.
Select “Geely” → “MK” from the vehicle list to confirm the immobilizer function is available.

Step-by-Step Guide to Program a Geely MK Key

Follow these steps in order. The LAUNCH X431 will guide you, but knowing what to expect prevents confusion.

1. Connect the LAUNCH X431 Scanner

Plug the OBD-II connector into the vehicle’s diagnostic port — located under the dashboard on the driver’s side, near the hood release or fusebox. Turn the ignition ON (engine off) so the instrument panel lights illuminate. Power on the scanner and wait for it to establish communication with the ECU. You should see a screen confirming “Connection Established.”

2. Access the Immobilizer / Anti-Theft System

From the main menu, tap “Diagnostics” → “Geely” → “MK” (or let it auto-detect the model). Then select “Immobilizer System” or “Anti-Theft System”. Depending on your scanner software version, this might also appear under “Body Control Module” or “Engine Management.”

First, run “Read System Information” to confirm the ECU part number and immobilizer type. This step also ensures the scanner is talking to the correct module.

3. Retrieve the PIN Code

Navigate to “Security Access” or “PIN Code Read” — some scanner versions call it “Read Key Code” or “Get PIN.” Follow the on-screen prompts:

If asked for a security access code, try default values like 0000 or 1234 first. Many aftermarket scanners accept these.
The scanner will then display a 4- or 5-digit PIN. Write it down immediately. You’ll need it in the next step.

Note: If the scanner cannot read the PIN, try an alternative method. Some Geely MK models have the PIN stored on a sticker on the immobilizer box itself (behind the glovebox). You can also use a dedicated PIN retrieval tool. If you hit “Security Access Failed,” wait 15 minutes before retrying — the immobilizer locks after multiple incorrect attempts.

4. Perform Key Programming

Now you’re ready to program a Geely MK key. Select “Key Programming” or “Add/Erase Key” from the immobilizer menu.

If you have at least one working key: Choose “Add Key”. This adds the new key while keeping existing keys active.
If all keys are lost: Choose “Program All Keys”. This erases all old keys and programs only the keys you present during the procedure.

When prompted, enter the PIN code you retrieved. Then:

Insert the new blank key into the ignition but do not turn it yet.
Follow the scanner’s on-screen instructions — typically: “Turn ignition ON for 3 seconds, then OFF.”
Repeat this for each key you want to program (if doing multiple).
The scanner will confirm with a message like “Key Learned” or “Key Programming Successful”.

5. Verify the New Key Works

After the scanner says programming is complete, remove the scanner from the OBD port. Turn the ignition off and wait 10 seconds. Test the new key by starting the engine. If it starts and runs, you’re done. Also test any existing keys to ensure they still work if you used “Add Key.”

If the engine doesn’t start, don’t panic — proceed to the troubleshooting section.

Troubleshooting Common Issues

Issue	Possible Cause	Solution
Scanner cannot read PIN	Outdated software; wrong model selection; low battery	Update scanner; verify vehicle model; charge battery or use booster
“Security Access Failed”	Incorrect PIN; immobilizer locked	Use another method to retrieve PIN; wait 15 minutes before retrying
Key not programmed after procedure	Transponder chip incompatible; distance too far	Ensure key has correct chip (ID46/ID48); hold key close to ignition ring
Engine starts then stalls	Immobilizer not recognizing key	Re-run programming; check if antenna ring is faulty
Scanner freezes during process	Bluetooth/wired connection issue	Restart scanner and vehicle; use wired connection if possible

If you’ve exhausted these fixes, refer to the scanner’s built-in help guide or visit online Geely owner forums for model-specific advice. For more on using your LAUNCH X431 for other vehicle systems, check out our guide on [link to guide on using LAUNCH X431 for diagnostics].

Frequently Asked Questions (FAQ)

Do I need a working key to program a new one on a Geely MK?

Not necessarily. If you have the PIN, you can program a new key even if all original keys are lost — use the “Program All Keys” function. However, some older Geely MK models require at least one working key for the “Add Key” feature. The LAUNCH X431 will tell you which option is available.

Can I use any LAUNCH X431 model?

Yes, any current X431 model (e.g., X431 V, PAD, Pro, Pro Mini) works, provided it has the Geely software package installed and updated. Older models like the X431 Diagun may also work but with limited functions. For the smoothest experience, use a model that supports pass-through programming.

What if my LAUNCH scanner does not have a Geely MK immobilizer option?

Try selecting a different Geely model (e.g., Geely MK1, MK2, or MK Cross). Some scanners group models under a generic “Geely” entry. Alternatively, use the “Automatic Model Identification” feature. If the option is still missing, contact LAUNCH support via their official website for a software update — [link to LAUNCH official support].

How do I obtain the PIN code without a scanner?

For some years, the PIN is printed on a small plastic tag attached to the key ring or inside the owner’s manual. If lost, a locksmith can read the PIN directly from the immobilizer box (located behind the glovebox or near the steering column). You can also remove the immobilizer module and read its EEPROM using a programming tool, but that’s more advanced.

Will programming a new key erase the existing keys?

It depends on the selected mode. “Add Key” preserves existing keys. “Program All Keys” erases all old keys and programs only the keys present during the procedure. Always confirm the on-screen warning before proceeding. If you accidentally erase keys, you’ll need to re-program them using the same PIN.

My engine still doesn’t start after programming. What else should I check?

Verify the new key’s transponder is working — use a transponder tester if available. Check for blown fuses, especially the ECU fuse or ignition fuse. Also ensure the scanner process completed fully — some Geely MKs require a 30-second wait after the last key is learned before turning the ignition off. As a last step, disconnect the battery for 5 minutes to force a full system reset, then test again.

Final Tips & Best Practices

Always keep the scanner connected until the procedure is fully completed. Disconnecting early can corrupt the programming.
If you encounter an “Error Code” during PIN reading, look up the code in the scanner’s help guide or online forum — it may point to a specific hardware fault.
For Geely MK vehicles with a passive immobilizer (no chip in the key), the programming method is completely different. Contact a dealer if you suspect your car has this setup.
After successful programming, test all keys immediately. Some models require a 5-minute ignition-off reset for the immobilizer to fully sync. Drive the car for a short trip to confirm everything works.
Keep a record of your PIN code in a safe place. You’ll need it if you ever need to replace a key in the future.
For more insights on immobilizer systems on Chinese vehicles, read our article on [link to related guide on similar topic].

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 Program a Geely MK Key Using LAUNCH X431 | Step-by-Step PIN Guide