Chery Car Programming 

How to Reset Immobilizer on Chery Arrizo 5 Using LAUNCH X431 (2026 Guide)

• June 17, 2026
Step-by-step guide to reset the immobilizer and relearn keys on a Chery Arrizo 5 using a LAUNCH X431 scanner. Includes PIN retrieval, troubleshooting, and expert tips.

Published: June 15, 2026

Quick Answer: How to Reset the Immobilizer on a Chery Arrizo 5

If your Chery Arrizo 5 won’t start or displays a “Key Not Detected” error, you likely need an immobilizer reset and key relearn. Using a LAUNCH X431 scanner, the process takes about 10 minutes:

  1. Connect the X431 to the OBD-II port and turn the ignition ON.
  2. Navigate to Chery > Arrizo 5 > Immobilizer (or BCM) system.
  3. Select Special Functions > Security Access (enter the correct PIN/Code via the X431 database or direct login).
  4. Choose Immobilizer Reset or Key Learning.
  5. Follow on-screen prompts to insert and turn the key to “ON” until the system confirms “Key Learned.”
  6. Turn ignition OFF for 10 seconds, then test the start function.

Note: You need the original master key and the correct security PIN; if unknown, the X431 often reads it automatically.

Understanding the Immobilizer System in the Chery Arrizo 5

What is an Immobilizer and Why Does It Fail?

The immobilizer is an electronic anti-theft system that prevents the engine from starting unless the proper transponder-equipped key is detected. In the Arrizo 5, the key contains a tiny chip that communicates with the Body Control Module (BCM) or Engine Control Unit (ECU). When you turn the ignition, the BCM sends a random challenge to the key, and the key responds with a matching code. If the codes don’t align, the ECU cuts fuel and ignition—leaving you stranded.

Common failure scenarios include:

  • A dying key fob battery or a damaged transponder chip.
  • Replacing the ECU or BCM after an accident or electrical failure.
  • A completely dead car battery causing the security module to lock out.
  • Adding a new spare key without properly syncing it.

I’ve seen many cases where a simple low-voltage jump-start causes the immobilizer to freak out because the BCM loses its volatile memory. That’s when a reset becomes necessary.

Critical: When to Perform a Reset vs. a Relearn

This is where many DIYers get stuck. There’s a difference between a full reset and a key relearn:

Procedure When to Use It What It Does
Immobilizer Reset After replacing the ECU, BCM, or key module. Wipes the old key data and returns the system to a “blank slate” state.
Key Relearn (Key Match) When adding a new key to an existing, functional system. Programmes the transponder ID of the new key into the BCM without erasing existing keys.

If you install a new ECU, you must do the reset first, then perform a key relearn. If you’re just adding a spare key and still have one working key, skip the reset and go straight to the relearn.

Tools and Preparation: Do Not Start Without This

The Right Scanner: LAUNCH X431 (V, Pro, PAD, or X)

A generic OBD-II code reader won’t cut it. The Chery immobilizer requires a bi-directional diagnostic tool that can initiate “Security Access” and “Write Key” commands. The LAUNCH X431 series is ideal because it supports the specific Chinese protocols used by Chery. Many of these protocols are not found in off-the-shelf scanners from big-box stores.

To perform the procedure, your X431 must have the Chery software package version V49.80 or higher. If you’re not sure, update the scanner over Wi-Fi before starting. The software includes the login module that retrieves the security PIN automatically—a huge time-saver.

What You Actually Need

  • Physical Key: The transponder chip inside the key must be within 2 inches of the ignition ring. Even a key fob with a dead remote battery can still work if the chip is intact.
  • VIN Number: If the scanner can’t read the PIN live, you’ll need the VIN to calculate it via the X431 database or an external generator.
  • Stable Vehicle Battery: I cannot stress this enough—the voltage must be 12.5V or higher. Low voltage during the write process will corrupt the key data and may brick the BCM. If your battery is weak, connect a battery maintainer.

Step-by-Step: Immobilizer Reset and Key Relearn Procedure

Step 1: Vehicle Connection and Scanner Setup

  1. Plug the X431 into the OBD-II port located under the driver’s side dashboard.
  2. Turn the ignition to ON (engine off). Do not start the car yet.
  3. On the X431, select Diagnosis > Chery > Arrizo 5 (or Arrizo 5 Pro/Ex, depending on the model year).
  4. Choose Auto Scan to let the scanner identify all modules. Look for the IMM (Immobilizer) or BCM (Body Control Module) entry.

Step 2: Entering the Immobilizer System

  • Manually select Immobilizer System if Auto Scan doesn’t find it. On some Arrizo 5 variants, it may be listed under BCM.
  • Critical Action: When the system prompts for a “Security Code” or “Login,” you are at the make-or-break point. Look for an option called Security Access.
  • Pin Retrieval:
    • Option A: Let the X431 read it automatically—select “Read Security Code.” Most X431 units with updated Chery software can pull the PIN directly from the BCM.
    • Option B: If that fails, use the VIN to calculate the PIN. Common factory PINs for early Arrizo 5 models include 1234, 0000, or the 4-digit code from the physical key tag (if you still have it).

Step 3: Performing the Immobilizer Reset (For New ECU/BCM)

Only follow this step if you’ve replaced the ECU or BCM. Otherwise, skip to Step 4.

  1. Navigate to Special Functions > Immobilizer Reset.
  2. A warning will appear: “Resetting… Do not turn off ignition.” Press OK.
  3. Wait at least 30 seconds. The scanner will display “Successful” or “Work Completed.”
  4. Turn the ignition OFF and back ON to confirm the reset.

Step 4: Key Relearn (Matching Keys to the ECU)

  1. Still inside the IMM menu, select Key Learning or Key Match.
  2. Prompt Action: Insert the Master Key into the ignition and turn it to ON (do not start the engine). The X431 will flash “Learn Master Key…” and then confirm “Key Learned.”
  3. Add a Second Key (if needed): Remove the Master Key. Immediately insert the second key and turn to ON. The scanner confirms “Key 2 Learned.”
  4. Confirm Quantity: The system counts keys. If you own three keys, program all three in one session. Once you leave the menu, any key not learned will be erased.

Step 5: Final Verification

  • Turn the ignition OFF. Wait 10 seconds.
  • Remove the X431 scanner.
  • Insert any programmed key and start the engine. The immobilizer light (a car icon with a key inside) should go off after a few seconds. If the Check Engine light remains steady, it’s likely a separate issue—not the immobilizer.

Detailed Troubleshooting: “Why Won’t It Work?”

Failure #1: “Security Access Denied” / Wrong PIN

Cause: The 4-digit PIN you entered is incorrect, or the BCM has entered a lockout mode after multiple failed attempts.

Fix: Do not brute force—you can lock the BCM for hours. Disconnect the scanner, turn the ignition OFF for at least 5 minutes, then retry using the VIN-based PIN from Chery’s server (requires an active X431 subscription). Some X431 units have a “Try All Possible Codes” function, but I only recommend that as a last resort.

Failure #2: “Key Learning Failed” Mid-Process

Cause: Signal interference, a weak transponder, or poor key-to-ignition proximity.

Fix: Hold the key physically closer to the ignition ring. In some Arrizo 5 models, the transponder reader is not right on the keyhole but under the steering column. Try placing the key on top of the BCM module (located behind the glovebox) if the ignition point fails.

Failure #3: The Scanner Does Not Find the “Immobilizer” Menu

Cause: Outdated X431 software or selecting the wrong model year.

Fix: Update the X431 via Wi-Fi. Alternatively, select a different Arrizo 5 model year (2016–2018 vs. 2019+). I once had to use Arrizo 5 Pro instead of the base model to access the immobilizer menu. If it still doesn’t appear, look under Chassis > Anti-Theft instead of Engine.

Comprehensive FAQ Section

Q: Do I need the original key to perform a relearn?

A: Yes. Most Chery Arrizo 5 systems require at least one valid, programmed master key to authenticate the learning process. If you have zero working keys, you need a “Key Lost” function (found on the X431 under Special Functions) or a dealer-level visit.

Q: Can I use a generic OBD-II scanner for this procedure?

A: No. The Chery immobilizer requires a bi-directional scanner like the LAUNCH X431. Generic code readers cannot perform the “Security Access” or “Write Key” functions.

Q: How long is the immobilizer reset process?

A: The software process takes approximately 5–10 minutes. However, locating the correct PIN or updating the X431 can add time.

Q: Will this reset clear my ECU tune or other coding?

A: No. The immobilizer reset only affects the anti-theft memory. It will not erase engine maps, transmission adaptations, or radio codes.

Q: Does the Arrizo 5 have a separate Immobilizer module?

A: In most Arrizo 5 models (2016–2023), the immobilizer function is integrated into the BCM (Body Control Module). In some early models, it is in the ECU.

Q: What should I do if the car starts but the immobilizer light stays on?

A: The key was likely learned, but there is a communication fault. Try a System Reset on the BCM via the X431 (Diagnosis > BCM > Special Functions > Reset BCM). If it persists, the coil around the ignition switch may be failing.

Final Expert Tips for a Successful Relearn

  • Battery Voltage is King: If your car battery is below 12V, the ECUs may refuse to write data. Connect a battery maintainer if necessary.
  • Key Quantity is Critical: The system counts keys. If you only program 1 key when you own 2, the second key will be erased. Program all keys in one session.
  • Be Patient with PINs: Many failures come from rushing the “Security Code” entry. If the X431 fails to read it automatically, check the physical yellow key tag (if you still have it) for a 4-digit number.

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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