Step-by-step guide to read the PIN code of a BYD Yuan Plus EV using the LAUNCH X431 IMMO Elite. Includes prerequisites, troubleshooting, and FAQs for key programming.

How to Read the PIN Code of a BYD Yuan Plus EV Using LAUNCH X431 IMMO Elite

Last Updated: May 26, 2026

Quick Answer

To read the PIN code of a BYD Yuan Plus EV using the LAUNCH X431 IMMO Elite, connect the tool to the vehicle’s OBD-II port, select BYD and the Yuan Plus model, navigate to the immobilizer menu, and choose “Read PIN Code.” The tool communicates with the Body Control Module and displays a 4- to 6-digit PIN within 30–60 seconds. Ensure the X431 has the latest software, the ignition is ON, and the 12V battery is fully charged.

What Is the PIN Code and Why It Matters for BYD Yuan Plus EVs

Think of the PIN code as the master password to your EV’s security system. Without it, you cannot program a new key fob, replace the Body Control Module (BCM), or add a remote key after losing all copies. The BYD Yuan Plus uses a high-security immobilizer that stores this unique code inside the BCM or the keyless go module. Each vehicle has its own PIN tied directly to the VIN – no two cars share the same code.

You will need this PIN in several real-world scenarios:

You lost all keys and need to program a new one.
You bought a used Yuan Plus and want to erase old keys and pair your own.
The BCM failed and you’re installing a replacement unit.
The key fob battery died and the emergency key does not start the car.

Without the PIN, a dealership visit (or expensive replacement of the entire BCM) becomes your only option. That’s why having a tool like the LAUNCH X431 IMMO Elite – and knowing how to use it – saves time and money.

Prerequisites and Preparations

Before you plug in the X431, a little preparation prevents frustrating errors.

Required Tools and Equipment

LAUNCH X431 IMMO Elite with an active subscription that covers BYD protocols. The IMMO Elite is specifically designed for immobilizer work, but you still need the right package enabled.
Stable internet connection – needed only during the initial software download. After that, the tool works offline.
Vehicle OBD-II port – on the BYD Yuan Plus, it sits under the dashboard on the driver’s side, near the steering column. It’s a standard 16-pin female connector.
Vehicle registration documents – some software versions prompt you to enter the VIN manually. Ownership proof may be required by the tool’s security policy.

Software and Firmware Requirements

The X431 IMMO Elite ships with a base firmware, but you must update it to the latest version for BYD support.

Connect the tool to Wi-Fi.
Tap System Update or Software Upgrade on the home screen.
Install all available updates.
Open the Immobilizer app and check if “BYD” appears in the make list. If not, download the BYD package from the Software Download menu.
Specifically look for “BYD Yuan Plus EV” or “BYD Yuan Plus” under the electric vehicle section.

Pro tip: Update the tool the night before you plan to use it. Updates can take 10–20 minutes.

Safety and Precautions

Check the 12V battery voltage. The Yuan Plus uses a small auxiliary battery for the electronics. It should read between 12.4V and 12.8V. Below 12.0V, the BCM may not communicate properly. Use a multimeter or the tool’s built-in voltage display.
Do not interrupt the connection while the tool is reading or writing data. A sudden disconnection can corrupt the BCM’s memory, leading to a no-start condition.
Turn the ignition ON but do not start the engine. On the Yuan Plus, press the start button once without pressing the brake pedal. The dashboard lights should illuminate. If the car has a keyless system, bring the key fob close to the steering column area.

Step-by-Step Guide: Reading the PIN Code

Follow these steps in order. If you miss a step, the tool may not connect or the PIN read may fail.

Step 1 – Connect the X431 IMMO Elite to the Vehicle

Action: Locate the OBD-II port under the dashboard. Plug the X431’s OBD-II cable firmly into the port. You will hear a click when it seats correctly.
Outcome: The tool powers on automatically. A green indicator light on the cable confirms power.
Check: Turn the ignition ON (push-to-start once without brake). The tool’s screen should show a “Connecting” message.

If the screen stays black, the OBD-II port may not be receiving power. Try turning the ignition to ACC first, then ON. If still no power, charge the 12V battery.

Step 2 – Access the Immobilizer Menu

Action: On the home screen, tap Immobilizer (the icon with a key symbol). Depending on your software version, it may be labeled Key Programming or IMMO.
Action: From the make list, tap BYD.
Action: Scroll to find BYD Yuan Plus or BYD Yuan Plus EV. If you see multiple model years, select the correct one (the tool usually lists a range like 2022–2025). Confirm the engine type as Electric.
Outcome: The tool loads the immobilizer functions for this specific model.

Step 3 – Execute the PIN Code Read Function

Action: In the immobilizer menu, tap Read PIN Code or Get PIN. Some versions label it Read Security Code.
Action: The tool will display a prompt: “Please turn ignition ON.” Confirm that the ignition is already ON (dashboard lights, no engine running). Tap Start or Next.
Outcome: The X431 now communicates with the BCM. You will see a progress bar and a message like “Communicating with ECU…”. Wait 30 to 60 seconds.
Outcome: A 4- to 6-digit number appears on the screen. For example: 123456 or 7890. Write it down immediately. The screen may not show it again after you exit.

Important: Some X431 versions allow you to tap “Save” or “Copy” – use that feature if available. Otherwise, snap a photo with your phone.

Step 4 – Verify the PIN (Optional but Recommended)

Action: In the same immobilizer menu, look for PIN Verification or Test PIN.
Action: Enter the PIN you just wrote down. Tap Start.
Outcome: The tool confirms whether the PIN is valid. If verification fails, do not assume the PIN is wrong. Re-read the PIN using Step 3. Occasionally, a communication glitch gives a false value. A second read usually corrects it.

Troubleshooting Common Issues

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

Problem 1 – Tool Does Not Connect to Vehicle

Possible causes: The OBD-II cable is loose, ignition is off, or the 12V battery is weak.

Solution: Re-seat the cable firmly. Verify ignition is ON (not just ACC). Measure the battery voltage – if below 12.0V, charge it with a battery maintainer for 30 minutes before retrying.

Problem 2 – Menu Does Not Show BYD Yuan Plus

Possible causes: Software not updated, or the BYD package is missing.

Solution: Connect the X431 to Wi-Fi, go to System Update, install all updates. Then open Software Download and manually download the “BYD Immobilizer” package. If the Yuan Plus still does not appear, select a generic “BYD Yuan EV” – the protocol is identical.

Problem 3 – PIN Read Fails or Returns “Error”

Possible causes: The BCM is in a security lockout mode. This happens after three failed read attempts in a row. The tool may also trigger a lockout if it tries incompatible communication protocols.

Solution: Turn the ignition OFF. Wait 60 seconds, then turn it ON again. Retry. If the error persists, wait 30 minutes (the BCM’s internal lockout timer) and try again with a fully charged 12V battery. Also, ensure the X431 IMMO Elite has the latest firmware – older versions have protocol bugs for the Yuan Plus.

Problem 4 – Display Shows “No PIN Found” or “0”

Possible causes: The PIN is stored in a location the tool cannot access, or the model selection is wrong.

Solution: Exit the immobilizer menu. Go back and select a slightly different model version – for example, if you chose “2023 Yuan Plus EV”, try “2022–2024 Yuan Plus.” Alternatively, manually enter the VIN when prompted (the tool may then re-identify the vehicle). If nothing works, contact LAUNCH technical support. In rare cases, the BCM firmware is so new that the tool needs a protocol update.

Advanced Tips and Context

Once you have the PIN, your work is only halfway done. Here is what experienced technicians know.

Handling Multiple PIN Attempts

The BYD BCM enforces a security lockout after three failed PIN reads within a short period. The lockout lasts 5 minutes. Track your attempts – if you get an error twice, wait before trying a third time. Better yet, use the verification feature to confirm a successful read rather than repeating the read function.

Alternative PIN Sources

If the X431 fails completely, check the vehicle’s key tag. Some BYD Yuan Plus models ship with a small plastic card that has the 4-digit PIN printed on it. This card is often stored in the owner’s manual wallet. If you have access to the original key fob but the car does not start, this card is your backup.

Comparison with Other Tools

The LAUNCH X431 IMMO Elite is the go-to tool for BYD EVs because it uses native Chinese manufacturer protocols. Other tools like the Autel IM508 or IM608 can also read the PIN, but they often require separate adapter cables (e.g., GBox or GProbe) for the Yuan Plus. The X431 works with its standard OBD-II cable. If you already own an Autel, it will do the job, but the X431 is more straightforward for this specific vehicle.

What to Do After Getting the PIN

With the PIN in hand, you can:

Program a new key fob using the Key Learning function in the immobilizer menu.
Replace the BCM and pair it to the vehicle.
Add or delete remote keys.

Each of these procedures requires the PIN again during the process. Write it on a sticky note and place it inside the owner’s manual for future reference – just keep it away from anyone who should not have access.

Frequently Asked Questions

Q1: Can I read the PIN code of a BYD Yuan Plus without the LAUNCH X431 IMMO Elite?

Only authorized BYD dealers or specialist immobilizer tools (like Autel IM508, Xhorse VVDI Pro) can read the PIN. The vehicle may have a printed PIN on a key tag – check your owner’s manual wallet first.

Q2: Is the PIN code the same for all BYD Yuan Plus models?

No. Each vehicle has a unique PIN tied to its VIN. You cannot use a PIN from another Yuan Plus.

Q3: What if I lose the PIN after reading it?

You can re-read it with the same tool as long as the BCM has not been replaced. Write it down securely – a note in the glovebox works, but a digital password manager is better.

Q4: The tool shows “Communication Error” – what should I do?

Check the OBD-II connector for bent pins. Ensure the ignition is ON. Try a different OBD-II cable if you have one. If the error persists, contact LAUNCH support for a vehicle-specific protocol file – they will email it to you after verifying your tool serial number.

Q5: Can the PIN read damage the vehicle’s electronics?

No. The tool only reads data; it does not write anything during the PIN read. However, if you accidentally disconnect the cable while the tool is communicating, you could cause a temporary glitch. Always follow the steps carefully, and avoid turning the ignition off mid-read.

Q6: Do I need an internet connection during the PIN read?

No. Internet is only needed for the initial software download. Once the BYD package is installed, the tool works offline.

Q7: The PIN is 4 digits – does the X431 show 6 digits sometimes?

BYD typically uses 4-digit PINs, but some models use 5 or 6 digits. The tool displays the exact length. Ignore any leading zeros – if the tool shows “0456,” the PIN is 456.

Q8: What do I do if the PIN read succeeds but key programming later fails?

The PIN is likely correct, but the key transponder type may be wrong. Confirm the key’s frequency (usually 433 MHz for the Yuan Plus). You may also need an additional security code – some models require a separate transponder password that the X431 can read after the PIN. Check the “Read Transponder Password” function in the same immobilizer menu.

Conclusion

Reading the PIN code of a BYD Yuan Plus EV with the LAUNCH X431 IMMO Elite is a straightforward job when you prepare properly. Update the tool, check the 12V battery, and ensure the ignition is ON before you start. Follow the step-by-step process – connect, select the model, read the PIN, and verify it. If you run into trouble, the troubleshooting guide covers the most common issues.

Once you have the PIN, you can program keys, replace the BCM, or perform other immobilizer tasks with confidence. Keep the PIN safe – it is your key to the car’s security system.

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 Read PIN Code of BYD Yuan Plus EV Using LAUNCH X431 IMMO Elite