Mechanic Wiki: Program Mitsubishi Mirage Attrage Key with LAUNCH X431

Learn how to program a Mitsubishi Mirage or Attrage key using a LAUNCH X431 scanner. DIY in 15 mins, save $100-200. Includes all-keys-lost procedure, troubleshooting, and FAQs.

Published: June 15, 2026

How to Program a Mitsubishi Mirage or Attrage Key with LAUNCH X431

Quick Answer: You can program a new or used key fob for a Mitsubishi Mirage or Attrage using a LAUNCH X431 scanner in under 15 minutes, typically without needing a locksmith or dealer visit. The process uses the scanner's immobilizer function via the OBD-II port to add, replace, or erase keys. Ensure your scanner has the latest Mitsubishi software and your vehicle battery is fully charged before starting.

Losing a car key or needing a spare is never convenient. For Mitsubishi Mirage and Attrage owners, the dealer visit can set you back $100 to $200, and a mobile locksmith isn't much cheaper. But if you own a LAUNCH X431 diagnostic scanner — or are thinking about getting one — you already have the power to program keys yourself. You just need to know the right steps.

In this guide, I'll walk you through the entire key programming procedure for a Mitsubishi Mirage or Attrage using the LAUNCH X431. Whether you're adding a spare or dealing with a complete key-loss situation, these instructions will save you time and money.

Before You Start: What You’ll Need

Before diving into the programming sequence, gather the following items. Skipping any one of them can cause the process to fail midway.

Required Tools and Materials

LAUNCH X431 scanner – Any model with Immobilizer/Key Programming capability (X431 PRO, PAD, V+, etc.) will work. If you don't own one, renting or borrowing one is also an option.
Working registered key – If you’re adding a spare, you need at least one key that already starts the car. For an all-key-lost scenario, you can still proceed — but you’ll need a programmable blank.
New key – The blade must be correctly cut to match your vehicle’s ignition cylinder, and the key must contain a compatible transponder chip. Aftermarket keys often work, but verify compatibility with your model year.
Fully charged 12V battery – A weak battery can interrupt communication between the scanner and the ECU. If your battery is borderline, connect a battery maintainer or jump pack.
Stable internet connection – Your X431 needs Wi-Fi to download the latest Mitsubishi software pack if you haven’t updated recently.

Software & Vehicle Compatibility Checklist

Before connecting the scanner, run through this checklist:

Update your X431 – Navigate to the software update section and download the latest Mitsubishi package. Newer model years may require updated protocols.
Confirm your vehicle – The LAUNCH X431 supports most Mirage and Attrage models from 2012 to present. Check your specific year in the scanner’s vehicle list.
Immobilizer system – All Mirage and Attrage models come with an immobilizer from the factory. This is the system you’ll be communicating with.

Common Safety Tips and Pitfalls

Do not interrupt the process – Keep hazard lights, the radio, and any other electrical loads off during programming. Interference can cause a failed write.
Hands off the key – Once the scanner begins communicating, don’t touch the key until instructed. Even a slight rotation can break the session.
Connection drops – If the scanner loses communication, wait at least 60 seconds before restarting the software. DO NOT turn the ignition off during this time.
Backup your existing keys – Before starting, note how many registered keys you currently have. If you accidentally erase everything, you’ll be stuck using the all-key-lost procedure — which is doable but takes a few extra steps.

Step-by-Step Key Programming Process

I’ve broken this down into five clear stages. Follow them in order, and you’ll have your new key working in 15–20 minutes.

1. Prepare the Scanner

Plug the LAUNCH X431 into the OBD-II port under the driver’s side dashboard.
Turn the ignition ON (engine off). All dashboard warning lights should illuminate.
Launch the LAUNCH X431 app and select Mitsubishi from the vehicle selection screen.
Choose Mirage or Attrage (they may appear as separate entries depending on your region). Confirm the correct model year.
Navigate to Special Functions > Immobilizer > Key Programming.

Pro tip: If you don’t see the Immobilizer menu, go back and select a different vehicle region (e.g., “China/Asia” instead of “USA”). Some import-market Mirage models require this tweak.

2. Enter the Immobilizer Menu

The scanner will read the vehicle’s VIN automatically. In some cases, it will also request a security access code (PIN).

Do you need a PIN?

Many Mirage and Attrage models do not require a manual PIN — the X431 can auto-calculate it.
If your model does need one and you have it (from a dealer or previous programming), enter it when prompted.
If you don’t have the PIN, the X431 can often retrieve it using a PIN Read function (may require a subscription or token).

Once inside the immobilizer menu, you’ll typically see options like Key Registration, Add/Delete Key, and Erase All Keys. The option you pick depends on your situation.

3. Register the New Key (Adding a Spare)

This is the most common scenario — you already have a working key and want to add a spare.

Insert the working registered key into the ignition and turn it to the ON position (engine off).
On the scanner, tap Start or Add Key.
The system will read the existing key data. This takes about 10–20 seconds. Wait for the confirmation beep.
Remove the working key from the ignition.
Insert the new key and turn the ignition ON.
The scanner will now write the new key’s transponder ID into the ECU. When you see “Key Registered Successfully” on the screen, you’re done with that key.
Test by turning the new key to START — the engine should crank and start.

Adding multiple keys? Repeat steps 1–6 for each additional key. The system can store up to 4–8 keys depending on the year.

3B. All Keys Lost Procedure

If you have no registered keys left (lost all keys, or bought a used car with only valet keys that won’t work), the procedure differs slightly:

In the immobilizer menu, select Erase All Keys first. This clears all stored key IDs from the ECU.
Select Register New Key.
Insert the new programmable blank key (must have a transponder chip — a cut-only metal key won’t work) and turn ignition ON.
The scanner will now program that key as a master/key. Only one key can be written per cycle. Repeat for additional keys.
A security PIN may be required for this procedure. Use the X431’s PIN Read function or retrieve the PIN from the dealer.

4. Program the Remote (Key Fob) – If Separate

On some Mirage and Attrage models, the key’s transponder and remote functions are handled separately. The transponder allows the engine to start, while the remote controls locking/unlocking.

If your new key fob has buttons and they don’t work after step 3, you need to sync the remote:

In the X431 menu, look for Key Fob / Remote Programming or BCM Programming.
Follow the on-screen prompts (usually: press LOCK or UNLOCK on the new remote).
The scanner will communicate with the Body Control Module (BCM) to learn the remote’s signal.
Test by locking and unlocking the doors with the fob.

5. Final Verification

Remove the scanner from the OBD-II port.
Start the engine using each programmed key. The immobilizer light on the dashboard should turn off after a few seconds.
Test all remote functions: lock, unlock, trunk release (if equipped), and panic button.
Check for any warning lights that remain illuminated. A flashing immobilizer light indicates a failed registration.

Troubleshooting Common Issues

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

Scanner Doesn’t Find Immobilizer Menu

Fix: Update your X431 software. Some model years require a newer database.
Fix: Change the vehicle region in the scanner settings (try “Asia/China” for import models).
Fix: Check OBD pin compatibility. Use a Mitsubishi-specific adapter if your scanner came with one.

“Key Not Detected” Error

This is the most frustrating error. Common causes:

The key is not in the ignition ON position (turned to the second click, not just ACC).
The transponder chip is damaged or missing. Aftermarket keys without a proper chip will not work.
The vehicle battery voltage is too low. Charge it or use a booster pack.
The antenna ring around the ignition cylinder has failed (rare but possible).

What to do: Try a known working key. If it also shows “not detected,” you likely have an antenna or ECU issue. If only the new key fails, replace the key.

Registration Count Limit Exceeded

The ECU can only hold a limited number of key IDs (usually 4–8). If you try to add a key when the system is full, the scanner will reject the request.

Solution: Use the Delete Key function to remove an old key you no longer need. You can also erase all keys and start fresh (but you’ll need to reprogram all your keys).

All-Keys-Lost Procedure Fails

If you followed the all-keys-lost steps but the scanner won’t write a new key:

Most likely the security PIN is required but missing. Use the X431’s PIN Read function (may cost extra). Alternatively, call a Mitsubishi dealer with your VIN — they can give you the PIN (usually free for owners).
The blank key may not be compatible. Ensure you have a programmable blank (e.g., for Mitsubishi transponder ID47 or ID4C depending on year).

Programming Successful but Engine Won’t Start

Check the immobilizer light. If it’s flashing rapidly or staying on, the key wasn’t fully registered.
Re-run the registration process. Occasionally, a weak scanner-to-ECU connection causes a partial write.
If the immobilizer light is off but the engine still doesn’t crank, you may have an unrelated issue (e.g., faulty starter or fuel pump relay). This is rare but possible.

Comparison: LAUNCH X431 vs. Dealer vs. Locksmith

Method	Cost	Time	Difficulty	Special Equipment
LAUNCH X431 (DIY)	$0 (if owned)	15–30 min	Medium	X431 + software
Mitsubishi Dealer	$100–$200	30–60 min	Easy (but costly)	Dealer-level tools
Mobile Locksmith	$80–$150	20–40 min	Low (they do it)	High-end key programmer

If you already own a LAUNCH X431, using it for key programming is essentially free. If you need to buy one, the cost may be higher than a single locksmith visit — but the scanner pays for itself if you work on multiple cars or plan to keep doing diagnostics.

Maintenance & Tips for Future Success

Remote battery replacement – The CR2032 battery inside your fob lasts 2–4 years. When the range drops, replace it before the remote dies completely.
Keep a spare key – Now that you’ve programmed one, it’s cheap to make another copy (just buy a blank and repeat the process). Keep it in a safe place.
Software updates matter – Mitsubishi occasionally updates immobilizer protocols on newer models. Check for X431 software updates once a month.
Write down your security PIN – During the first successful programming, the scanner may display a PIN code. Write it down and store it with your vehicle documents. This saves hours in an all-key-lost situation later.

Frequently Asked Questions

1. Do I need the original master key to program a new key? No. The LAUNCH X431 can add a new key even if you only have a working valet key (or any registered key). For an all-keys-lost situation, it can still program from scratch — you just need the PIN and a programmable blank.

2. Can I program a used key from another Mitsubishi? Yes, but the scanner will automatically erase the previous immobilizer data during registration (it “flashes” the transponder). However, some OEM-locked keys may refuse overwriting. In that case, buy a fresh blank — they’re inexpensive online.

3. How many keys can I program to a Mirage or Attrage? Most models support between 4 and 8 keys total. The scanner will show you your current count. If you hit the limit, delete an old key first.

4. Will programming a new key delete my existing keys? Only if you explicitly choose Erase All Keys. The standard Add Key function preserves all previously registered keys. For added safety, confirm how many keys are registered before starting.

5. What if the scanner says “Function Not Supported”? This usually means your software doesn’t cover that exact model year or region. Update the X431 to the latest Mitsubishi package. If it still fails, select a slightly different year (e.g., 2015 instead of 2016). For export models, try the “China/Asia” region setting.

Conclusion

Programming a key for your Mitsubishi Mirage or Attrage with a LAUNCH X431 is a practical and cost-saving DIY task. You don’t need to be a mechanic — just follow the steps carefully, keep your scanner updated, and test everything before buttoning up.

For the cost of a dealer visit, you could buy your own X431 and program keys for years to come. And if you ever find yourself locked out with no working keys, the all-keys-lost feature is a lifesaver. Practice once with an old key to build confidence. Then keep a spare programmed and ready — you’ll never pay for a locksmith again.

For more diagnostic and key programming guides, check out our article on [link to related guide on similar topic] or [link to another guide on LAUNCH X431 features].

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/

Program Mitsubishi Mirage Attrage Key with LAUNCH X431 | Step-by-Step Guide