Changan Key Programming 

Program Changan CX70 Key with LAUNCH X431: Step-by-Step Guide

• May 31, 2026
Learn how to program a new key for the Changan CX70 using LAUNCH X431. Includes PIN code tips, troubleshooting, and immobilizer & remote coding steps.

How to Program a New Key for the Changan CX70 Using LAUNCH X431

Last Updated: June 1, 2026

Quick Answer: Can You Program a Changan CX70 Key with a LAUNCH X431?

Yes, the LAUNCH X431 series (including the X431 Pro, X431 V+, and X431 PAD VII) can program a new key fob for the Changan CX70. The tool handles the immobilizer (IMMO) protocol directly, but you need a valid 16-digit PIN code (obtained from the vehicle’s BCM or a paid database) and a blank, uncut transponder key compatible with the CX70’s frequency (315MHz or 433MHz). The process typically takes 10–15 minutes per key.

What You Need Before Starting

Before diving into the programming procedure, gather these essentials. Missing any one of them will stop the process cold.

Item Purpose Notes
LAUNCH X431 device Runs the immobilizer software Must have the latest Changan software pack installed
Working original key Required to enter programming mode Without it, you’ll need the “All Keys Lost” paid add-on
Blank transponder key New key to be programmed Must be a 46 or 4C chip; pre-cut hardware store keys won’t work
16-digit security PIN Unlocks the ECU for key learning Get it via the X431’s “Read PIN” function or from a database
Battery maintainer Prevents voltage drops during programming A sudden voltage dip can brick the ECU
OBD-II cable (included with X431) Connects tool to vehicle Ensure the pins are clean and the connection is secure

Warning: Do not skip the battery maintainer. Many DIYers fail because the vehicle’s battery voltage drops below 12.0V during the IMMO learning sequence, causing the ECU to lock up.

Step-by-Step: Programming a New Key (Immobilizer & Remote)

Follow these steps in order. The LAUNCH X431 will guide you with on-screen prompts, but knowing the sequence beforehand saves time.

1. Connect and Identify the Vehicle

  1. Sit in the driver’s seat with the working original key.
  2. Turn the ignition ON (engine off) using that original key.
  3. Connect the LAUNCH X431 to the OBD-II port — it’s under the dashboard, near the steering column.
  4. On the tool’s home screen, tap Diagnosis > Changan > CX70.
  5. Let the system read the vehicle’s VIN automatically. This takes 10–15 seconds.

If the VIN does not appear automatically, you can enter it manually. You’ll find it on the driver’s side door jamb sticker or on top of the dashboard near the windshield.

2. Navigate to the IMMO / Key Program Function

  1. From the main menu, select Immobilizer (IMMO) .
  2. Choose Key Programming or Learn New Key (the exact label varies slightly by software version).
  3. The tool will prompt you to enter the 16-digit Security PIN. Type it carefully — one wrong digit and the ECU may lock you out after three attempts.

Where do you get that PIN? If you don’t have it already, the X431 can often read it directly from the BCM. Select the “Read Security Code” option under the IMMO menu with a working key in the ignition. If that fails, you’ll need to buy the code from an online database (services like AutoKeyPro or CarDumps typically charge $5–$15).

3. Enter Programming Mode

  1. The LAUNCH will now display a sequence of instructions. Follow them exactly:
    • Insert Key 1 (original) → Turn ignition to ON → Wait 3 seconds → Turn to OFF.
    • Remove Key 1.
    • Insert Key 2 (the new blank) → Turn ignition to ON.
  2. Watch the dashboard’s immobilizer light — it’s the little key icon. It should either turn solid or blink rapidly, indicating the new key’s transponder is being learned by the ECU.
  3. Keep the new key in the ON position for about 10 seconds. The X431 will show a “Learning Successful” message.

Important: If you want to keep your original key working, you must re-program it too. The ECU clears the entire key list when you start the programming process. So before removing the new key, insert the original again and follow the same “insert → ON → wait” sequence. The X431 will allow you to add multiple keys in one session.

4. Program the Remote (Fob) Function

The immobilizer chip is done, but the remote buttons (lock, unlock, trunk) may not work yet. The LAUNCH will usually provide a Remote Key Code or a button-learning sequence after the immobilizer step.

If the tool’s automatic remote coding fails, try this manual method:

  1. Within 10 seconds of completing the immobilizer learning, press and hold the UNLOCK button on the new fob for 5 seconds.
  2. Release the UNLOCK button.
  3. Press LOCK + UNLOCK simultaneously for 3 seconds.
  4. Test the door locks by pressing LOCK once. If they respond, the remote is paired.

Some CX70 model years require you to cycle the ignition (OFF → ON → OFF) before the BCM accepts the remote code. If the manual method fails, turn the ignition OFF, wait 10 seconds, turn ON again, then repeat the button sequence.

5. Final Test and Exit

  1. Turn the ignition OFF.
  2. Remove the new key and test every function:
    • Engine start — Does the car crank and run?
    • Door locks — Does the remote lock and unlock all doors?
    • Trunk release — If your fob has a trunk button, test it.
  3. Reconnect the LAUNCH X431 and clear any Diagnostic Trouble Codes (DTCs) that were generated during programming. You’ll find this under the Diagnosis > Read Fault Codes menu.
  4. Disconnect the tool and the battery maintainer.

Troubleshooting: Why It’s Not Working

Even with the right tool and steps, things can go wrong. Here are the most common problems and how to fix them — I’ve seen each of these in real-world workshops.

“Wrong PIN” Error

This is the number one issue. The 16-digit code you entered is not what the ECU expects.

Solution: Use the LAUNCH’s “Read Security Code” function under the IMMO menu with a working key. If that fails, locate the BCM module (usually behind the glove box). Look for a white sticker with a 4- or 5-digit code printed on it — sometimes labeled “Code: 1234.” You can decode this into the 16-digit PIN using a Changan-specific algorithm accessible through the X431’s calculator tool. If you’re still stuck, purchase a fresh PIN from a reputable database.

“Communication Failure”

The tool cannot talk to the ECU.

Solution: Force a reconnect. Turn the ignition OFF, wait 10 seconds, then turn ON again. Also check the OBD cable — a loose or dirty connection will cause this error. If the problem persists, try a different OBD-II port (some CX70 models have two ports: one under the dash and one near the center console).

“Key Not Learned”

The tool accepted the PIN, but the new key’s transponder wasn’t written.

Solution: This usually means the blank key you bought is the wrong chip type. The CX70 requires a 46-type glass transponder (or sometimes a 4C chip in earlier models). If you bought a universal blank that claims to work with many cars, it may not have the correct chip. Buy a key specifically labeled “For Changan CX70 / CS35 / CS75” from a locksmith supplier. Also confirm the frequency: 315MHz for most Asian-market CX70s, 433MHz for some export versions.

Remote Works, But Car Won’t Start

The immobilizer chip was learned, but the remote fob coding failed — or vice versa.

Solution: The ECU recognizes the key’s transponder, but the BCM doesn’t recognize the remote signal. Re-run only the Remote Coding sub-menu (not the full IMMO procedure). Turn the ignition ON, go to IMMO > Remote Coding, and follow the on-screen button-press sequence again. This will not affect the already-learned immobilizer data.

“Procedure Failed — ECU Locked”

You entered the wrong PIN three times in a row.

Solution: Turn the ignition OFF and disconnect the battery for 15–20 minutes. This resets the ECU’s lockout timer on most Changan models. After reconnecting, start the process fresh with the correct PIN. If it locks again, you may need dealer-level software to unlock it — a locksmith can help.

Advanced Tips and Context

How to Get the PIN Code (If You Don’t Have It)

  • Method A (Easiest): Use the LAUNCH X431’s “Read Security Code” function under IMMO. This works as long as at least one working key is in the ignition. The tool reads the code from the BCM in about 30 seconds.
  • Method B (Manual): Physically remove the glove box (two screws at the top, then pull it out). Locate the BCM — a black box with multiple wiring harnesses. Look for a white sticker with a 4- or 5-digit number. That number is the “raw” security code. To convert it to the 16-digit PIN, use the X431’s “Changan Security Code Calculator” tool (under IMMO > Special Functions). The algorithm is model-year specific, so make sure your tool’s software is up to date.

Can You Program a Key Without Any Working Key?

For the CX70, the answer is no — unless you have the LAUNCH X431’s “All Keys Lost” function activated (a paid subscription) and the manufacturer-level dealer software add-on. Even then, it’s more complex and requires entering the PIN manually. For most users, you need at least one working key to enter programming mode. If you’ve lost all keys, call a professional locksmith who has the correct dealer-level tools.

What About the LAUNCH X431 “X431 Pro”?

The X431 Pro works identically to the PAD VII for this car. The steps in this guide apply to all X431 models that support “Immobilizer” functions — including the X431 V+, X431 PAD V, and X431 PAD VII. The only difference is screen size and user interface layout.

Does Programming Delete Old Keys?

Yes, for the immobilizer. When you program a new key, the ECU clears the authorized transponder list. You must re-program all keys you want to keep (including the original and the new one) in the same session. The remote fob coding, however, is separate — the BCM typically stores up to four remote codes, so adding a new one does not erase old ones (but it’s still a good idea to test all remotes after the procedure).

Can I Program a Used Key from Another CX70?

No. Transponder keys are “married” to the ECU they were first programmed to. A used key from another CX70 will still carry the old encryption data. Programming a used key requires specialized equipment (a transponder reader/writer) to erase and re-flash the chip — the standard LAUNCH X431 cannot do this. Always buy a new, blank key for programming.

Frequently Asked Questions (FAQ)

How much does it cost to program a Changan CX70 key with LAUNCH?

If you own the tool, your cost is just the blank key ($10–$30) plus any PIN code fee ($5–$15 from online databases). Locksmiths typically charge $100–$200 for this service.

Do I need a special blank key?

Yes. The CX70 uses a 46-type glass transponder for the immobilizer and a 315MHz or 433MHz remote frequency. Not all universal blanks work. Buy one specifically labeled for the Changan CX70 or CS models.

Will programming delete my old keys?

Yes, for the immobilizer. When you program a new key, the ECU clears the list of authorized transponders. You must re-program all keys you want to keep (including originals) in the same session.

What if the LAUNCH says “Procedure Failed – ECU Locked”?

This means you entered the wrong PIN too many times (usually 3 attempts). Turn ignition OFF for 15–20 minutes with the battery disconnected to reset the ECU’s lockout timer on most Changan models.

Can I program a used key from a different CX70?

No. Transponder keys are “married” to the ECU. Used keys must be fully erased and re-flashed, which requires specialized equipment not standard on the LAUNCH X431. Always buy a new, blank key.

For more details on LAUNCH X431 immobilizer features, check out our guide on [link to related guide on programming keys with LAUNCH X431]. If you’re new to diagnostic tools, our article on [link to beginner’s guide to OBD scanners] will help you get started.

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/

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