Peugeot Key Programming 

How to Recover All Keys Lost on Peugeot 308 with LAUNCH X431 IMMO

• June 03, 2026
Step-by-step guide to program a new key for a Peugeot 308 with zero keys using LAUNCH X431 IMMO. Includes prerequisites, troubleshooting, and FAQs.

Published: June 3, 2026

Quick Answer

Yes, you can recover a Peugeot 308 that has zero keys using a LAUNCH X431 IMMO tool. The process uses the "All Keys Lost" function to bypass the immobilizer and program a new blank key from scratch. Expect 15–30 minutes of work, but you’ll need a compatible blank key, stable battery voltage above 12.5V, and at least one paid LAUNCH credit token to complete the job.

Why the "All Keys Lost" Scenario Is Different

Losing every key to your Peugeot 308 is a stressful situation. Without any working key, you can’t start the engine, and even a standard locksmith may struggle because the immobilizer system is locked tight. The car’s Built-in Systems Interface (BSI) stores the unique transponder IDs of all authorized keys. When none exist, the BSI refuses to cooperate with any new key unless you use a specialized tool that can break into that encrypted data.

That’s where the LAUNCH X431 IMMO software shines. Unlike a simple "Add Key" routine (which needs one working key to copy from), the "All Keys Lost" function sends a bypass signal directly to the BSI, allowing you to teach it a brand-new transponder. This is not a DIY job for a generic OBD scanner—only high-end diagnostic platforms like the LAUNCH X431 Pro, V+, or V5.0 with the IMMO module can pull it off.

Prerequisites and Preparations

Before you plug anything in, gather these three essentials. Skipping any one of them can turn a 20-minute job into a tow to the dealership.

Stable Battery Voltage (12.5V or Higher)

Programming the immobilizer draws significant current. If the battery voltage drops below 12.5V during the process, the X431 may lose communication with the BSI, corrupting the data. Connect a battery maintainer or a smart charger to the car’s battery terminals before you begin. Don’t rely on a trickle charger that can’t keep up with the load.

A Compatible Blank Key

You need an unprogrammed transponder key that matches your Peugeot 308. The most common chip type is the PCF7935 (ID44), but some newer models use a T5 or even a crypto chip. Check your vehicle’s year and region. For best results, use a genuine Peugeot blank or a high-quality aftermarket equivalent from a reputable supplier. A cheap generic key may fail to program or drop out later.

Tip: If you’re unsure of the chip type, the LAUNCH X431 can sometimes read the required key information when you start the "All Keys Lost" procedure.

LAUNCH X431 Credits

The "All Keys Lost" function typically consumes one paid token from your LAUNCH account. These credits cost between $20 and $50, depending on your subscription plan and region. Log into your X431 account and verify you have at least one credit available before connecting to the vehicle. Running out mid-session will leave you stuck.

Step-by-Step: Recovering All Keys Lost on a Peugeot 308

Follow this procedure exactly. The menu names may vary slightly depending on your X431 software version (V5.0, V+, or V9.0), but the logic is the same.

1. Connect and Identify the Vehicle

  • Plug the LAUNCH X431 into the OBD-II port under the dashboard (driver’s side, near the steering column).
  • Turn the ignition ON (dashboard lights up). Do not attempt to start the engine.
  • On the X431, navigate to: Diagnostic > Peugeot > 308.
  • Select the correct model year or choose Auto Detect VIN to let the tool identify the car automatically.

2. Access the Immobilizer Menu

  • From the main diagnostic screen, tap Immobilizer (IMMO) .
  • Look for a submenu labeled All Keys Lost, Emergency Start, or Key Learning. The exact wording depends on your X431 firmware version.
  • Important: Do not accidentally select "Add a Key" – that function requires at least one working key to proceed.

3. Enter the All Keys Lost Mode

  • The tool will ask you to confirm that zero keys are available for programming. Select Yes.
  • You’ll be prompted to enter the vehicle’s security PIN (also called the immobilizer code). This is a 4‑ or 5‑digit number unique to your car.
    • Option A – Known PIN: If you have the code (from the car’s manual, a previous owner, or a locksmith), enter it manually.
    • Option B – Auto Retrieval: Most LAUNCH X431 units include an Auto Code Retrieval function that reads the PIN directly from the BSI via the OBD port. This works on the majority of Peugeot 308s built up to around 2015–2016.

4. Retrieve the PIN (If Using Auto Retrieval)

  • If you choose auto retrieval, keep the ignition ON. The X431 will communicate with the BSI and display the security code.
  • Write this code down immediately. You may need it again if the programming fails or if you ever need to add a key later.
  • Enter the code when the tool prompts you.

5. Program the New Key

  • The X431 will now send a bypass signal to the BSI, telling it to accept a new transponder.
  • You will see a message such as: "Insert new key into ignition and turn to position M (ON)."
  • Insert your blank key into the ignition and turn it to the ON position (just before the engine crank). Do not start the engine.
  • The tool will display "Programming..." for about 30 to 90 seconds. Do not touch the ignition, the key, or the scanner during this time. Any interruption can corrupt the BSI memory.

6. Confirm and Test

  • A success message will appear: "Learning Complete. 1 Key(s) Programmed."
  • Turn the ignition OFF and remove the key.
  • Test the key: re-insert it and start the engine. If the engine fires up, your recovery is complete.
  • If the engine does not start, leave everything connected, wait 60 seconds, and repeat Step 5 using the same key. Sometimes the BSI needs a second attempt to fully register the transponder.

Common Problems and How to Fix Them

Even when you follow every step, issues can arise. Here’s a quick troubleshooting reference.

Symptom Likely Cause Solution
"ECU Not Responding" Low battery voltage or poor CAN bus connection. Recharge the battery with a maintainer, check OBD pins for corrosion, or try a different X431 cable.
"Wrong Security Code" The auto-retrieved PIN is incorrect or corrupted. Use a third-party service (e.g., "Peugeot PIN by VIN") to get the official code from the manufacturer database.
"Failed to Program Key" The transponder chip is faulty or the key is the wrong type. Replace the blank key with a genuine Peugeot part or a verified PCF7935 compatible blank.
"Tool Won’t Enter IMMO Menu" The LAUNCH software needs an update or credits are missing. Update the X431 firmware via Wi-Fi, then buy a new credit token from your account.
Car starts but immobilizer light stays on The key is partially programmed or BSI data is corrupted. Clear diagnostic trouble codes using the X431, then run a "BSI Reset" (if available) and repeat the key learning step.

Going Deeper: What You Need to Know Beyond the Basics

Understanding a few surrounding topics will help you avoid costly mistakes and get the most out of your LAUNCH X431.

Why "All Keys Lost" Costs a Credit While "Add Key" Is Free

When you have one working key, the LAUNCH tool can simply read its transponder ID and duplicate it to a new blank via the "Add Key" menu. That process is straightforward and doesn’t require breaking the BSI’s encryption lock. In contrast, "All Keys Lost" forces the tool to bypass the immobilizer’s security countermeasures, which consumes a paid token. That token covers the cost of the server-side decryption that the X431 communicates with during the procedure.

Peugeot 308 BSI Lockout Risks

Modern Peugeots (especially 2010+) track how many key programming attempts you make. If you fail multiple times in one session, the BSI can enter a lockout mode that prevents any new key learning for 24 to 48 hours. Worse, a sudden voltage drop during PIN extraction can erase the BSI’s memory entirely, turning your car into a brick that only a dealer can recover. That’s why using a battery maintainer and following the steps precisely is non-negotiable.

After Programming: Cutting the Key and Pairing the Remote

The LAUNCH X431 IMMO procedure only links the transponder chip inside your key to the car’s immobilizer. It does not cut the metal blade or program the remote door-lock buttons.

  • Key cutting: Take the newly programmed key to an automotive locksmith. They can cut the blade to match your door and ignition lock cylinders based on your VIN.
  • Remote fob pairing: To make the lock/unlock buttons work, go back to the X431’s BSI menu and look for a Remote Programming or Key Fob Pairing function. Follow the on-screen instructions to sync the fob with the BSI. This step typically requires the ignition to be cycled a specific number of times.

Comprehensive FAQ

1. Can I use the LAUNCH X431 Pro or X431 V+ for this?

Yes. The procedure is identical across the X431 Pro, V, V+, and V5.0. The key requirement is that the IMMO software is installed and you have active credits. For newer models (2018+), you might need a bypass module like the X10 or KC501—check the tool’s compatibility database before starting.

2. Is it possible to recover keys without the original PIN code?

Yes. The LAUNCH X431 usually has a built-in PIN retrieval feature that pulls the code directly from the car’s BSI. This works about 90% of the time on Peugeot 308 models up to 2015. For newer vehicles, you may need to obtain the PIN from a dealer or a third-party VIN-decoding service.

3. What if the LAUNCH tool fails in the middle of programming?

Do not remove the tool or turn off the ignition. This is the most critical rule. Leave everything connected and call LAUNCH technical support or your equipment supplier immediately. Forcing a reset—even by disconnecting the battery—can corrupt the BSI’s flash memory. If possible, let the car’s battery drain (you are on a maintainer, so it won’t) rather than unplugging the scanner.

4. How many keys can I program during an "All Keys Lost" session?

Typically, you can only program one key per session because the BSI expects to learn a single master key. If you need two keys, you have two options: program the second key immediately after the first while the BSI is still in learning mode (check your X431 manual for this feature), or repeat the entire "All Keys Lost" procedure (which consumes another credit).

5. Will this work on a 2018 or newer Peugeot 308?

For models after 2016, the direct "All Keys Lost" support can be limited due to stricter encryption. You may need a bypass module like the LAUNCH X10 or KC501 to access the BSI. Always verify the supported model years in your X431’s software database before purchasing credits.

6. Can a locksmith do this cheaper than a dealer?

Absolutely. An automotive locksmith with a LAUNCH X431 can usually perform an "All Keys Lost" recovery for $100 to $250, including key cutting and programming. A Peugeot dealership may charge $300 to $600, plus towing fees if the car isn’t drivable. Going through a locksmith is often the most cost-effective route.

7. My engine starts but the steering lock doesn’t release. Is this normal?

Yes. The LAUNCH X431 IMMO process does not typically program the electronic steering lock (ELV) actuator. You may need to run a separate diagnosis on the steering lock module using the X431’s system scan, or manually rotate the steering wheel left and right while starting the engine to disengage the lock.

For more details on the full range of LAUNCH X431 IMMO functions, check out our guide on [link to related guide on LAUNCH X431 IMMO functions].

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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