Mechanic Wiki: How to Program BMW G11/G12 Keys with LAUNCH X431 IMMO Plus (2026)

Step-by-step guide to program a new key for BMW 7 Series G11/G12 (2015-2019) using LAUNCH X431 IMMO Plus. Includes S-Code retrieval, troubleshooting tips, and FAQ.

Let me write the blog post following your detailed instructions, including the date, author bio, active voice, step formatting, and FAQ with natural language questions.Published: May 28, 2026

Quick Answer: Programming a BMW G11/G12 Key with LAUNCH X431 IMMO Plus

The LAUNCH X431 IMMO Plus can program a new key for a BMW 7 Series G11/G12 (2015-2019) without needing the original master key, provided you have the 20-digit security code (S-Code) or can retrieve it via the tool’s online database. The core process involves connecting the X431 to the vehicle’s OBD-II port, navigating to the IMMO or Key Programming function, entering the security code, and then following the on-screen wizard to learn the new key. For a full procedure, including troubleshooting "Key Not Recognized" errors and handling CAS4/CAS5 modules, follow the detailed steps below.

Prerequisites and Tool Preparation

Before you dive into the programming sequence, you need to gather the right tools and understand the BMW’s security system. Skipping any of these preparation steps often leads to failed attempts or, worse, a corrupted CAS module.

What You Need to Start

LAUNCH X431 IMMO Plus – Make sure you have the latest software update installed. An outdated firmware can cause the tool to freeze or misread key data. Connect the tablet to a stable Wi-Fi network and run the update check before you begin.
Original key (if you are adding a key) – For a key addition, you still need at least one working key to authenticate the process. If you have lost all keys, you will need a Pen Type EEPROM Programmer to read the CAS module directly.
20-Digit Security Code (S-Code) – This code is unique to your vehicle’s CAS module. You can retrieve it automatically using the X431’s online function, or you can enter it manually if you obtained it from a dealer or a previous diagnostic session.
Stable 12V Battery Charger – I cannot overstate this: a voltage drop below 12.0V during the write EEPROM phase can permanently corrupt the CAS module. Always connect a battery maintainer or a smart charger to the jump-start terminals under the hood before you start.

Identifying Your BMW G11/G12 Security System

The G11 and G12 generations use a CAS (Car Access System) module, not the older EWS system found in earlier BMWs. The most common versions you will encounter are:

CAS3+ (rare on G11/G12, but possible on early 2015 models)
CAS4 (most common on 2015–2017 models)
CAS4+ (common on 2017–2019 models)

To identify your exact module, locate the CAS unit behind the glovebox or under the driver’s side dashboard. It is a small black box with a multi-pin connector. The label will show something like "CAS4+ 0.9.0". Knowing this version helps you choose the correct programming path in the X431 menu.

Step-by-Step Key Programming Process

Step 1: Connect and Enter IMMO Functions

Plug the LAUNCH X431 into the vehicle’s OBD-II port. On the G11/G12, you will find the port under the driver’s side footwell, usually covered by a small plastic flap.
Power on the tool. Select BMW from the main menu, then choose Auto Detect to let the tool identify the vehicle. Alternatively, manually enter the vehicle model (e.g., 7 Series G11).
Once the vehicle is recognized, navigate to IMMO (Immobilizer) from the function list.
From the IMMO submenu, select Key Programming. The tool will now attempt to communicate with the CAS module.

Step 2: Retrieve or Enter the Security Code (S-Code)

This step is the most critical. Without the correct 20-digit S-Code, the X431 cannot authorize key learning.

Option A – Automatic Retrieval: Select Read Security Code. The tool will try to calculate the S-Code from the VIN and the CAS module data. This process usually takes 2–3 minutes and requires an active subscription or diagnostic credits. If the tool succeeds, it will display the 20-digit code on screen. Write it down or take a photo – you may need it again later.
Option B – Manual Entry: If you already have the S-Code (from a dealer invoice, a previous diagnostic session, or a sticker inside the glovebox), select Enter Security Code and input the 20-digit number carefully. One wrong digit will cause the "Key Not Recognized" error.

A common mistake I see: many technicians skip the automatic retrieval and try to enter the code without verifying its accuracy. Always double-check the code if you are typing it manually.

Step 3: Perform the Key Learning Procedure

From the Key Programming menu, select Learn Key.
Insert the original working key into the ignition slot (or place it on the Comfort Access reader pad if your model uses push-to-start without a physical slot). Turn the key to position "1" (accessory power). The X431 will read the key data and display the number of keys already programmed (typically 2–4).
Remove the original key and insert the new, virgin key fob. Turn it to position "1" as well. The tool will detect the new key and prompt you to start the engine.
Press the start button (or turn the key to the start position) and let the engine run for about 3 seconds. The dashboard should show "Key Recognized" or the tool will display a success message.
Turn off the ignition and remove the new key. Repeat the process for any additional keys you want to program (you can program up to 6 keys total).

Step 4: Verify Remote Functions

Exit the IMMO menu and go back to the main diagnostic screen.
Test the new key’s lock and unlock buttons. Check all doors and the trunk.
If your car has Comfort Access (keyless entry), touch the door handle to verify it locks and unlocks without pressing any buttons.
Important: If the remote functions fail but the key starts the engine, you need to perform a Body Domain Controller (BDC) reset. Go to the X431’s Special Functions menu, select BDC Reset, and follow the prompts. This syncs the key’s remote signal with the car’s body module.

Advanced Troubleshooting and Common Pitfalls

Even with the right tools, you may run into issues. Here are the three most common problems I have encountered and how to solve them.

Issue: "Key Not Recognized" Error on Screen

Cause: This error usually means the S-Code is incorrect, the battery voltage dropped during learning, or the CAS module entered sleep mode.
Fix:
- Re-read the S-Code using the EEPROM method. This requires removing the CAS module from the vehicle, opening its case, and using the X431 IMMO Plus EEPROM Adaptor to read the 95080 or 95160 memory chip. The tool will then extract the S-Code directly from the chip.
- Connect a battery charger and ensure the voltage stays above 12.5V throughout the entire procedure.
- Manually wake the CAS module by pressing the start button without touching the brake pedal. The dashboard lights should come on. Then repeat the learn key process.

Issue: Key Learned, but Engine Won't Start

Cause: This happens when the immobilizer sync between the CAS and the DME (engine control unit) fails. It is common after a battery disconnect or a CAS replacement.
Fix: Use the X431 to perform a CAS Synchronization. Navigate to IMMO > Special Function > CAS Sync. Run the procedure – it takes about one minute. Then re-learn the key following Step 3 again. After syncing, the engine should start immediately.

Issue: Tool Freezes During "Reading Key Data"

Cause: An outdated X431 firmware or a poor OBD-II connection (bent pins, loose cable).
Fix:
- Update the LAUNCH X431 software to the latest version via Wi-Fi before any key programming attempt. The update typically takes 10–15 minutes.
- Use a high-quality OBD-II extension cable. The G11/G12’s OBD port is sometimes recessed, and the tool’s connector may not seat fully without an extension. A loose connection causes intermittent communication that freezes the tool.

Post-Programming Verification and Tips

Once the key starts the engine and remote functions work, you are not quite done. A few final checks ensure the job is fully successful.

Completing the Setup

Check for fault codes: After programming, scan the CAS and BDC modules for any IMMO-related codes, such as "Key Voltage Low" or "Invalid Transponder". Clear them using the X431’s diagnostics feature.
Program additional keys: If you have more than one new key, repeat the learning process for each key one at a time. Do not try to program multiple keys in one session – the system handles them sequentially.
Test all doors: Walk around the car and verify that the key operates the driver’s door, passenger door, and trunk release. Also check that the panic button functions correctly.

Why You Should NOT Skip the Battery Charger

I mentioned it earlier, but it deserves its own spotlight. During the Write EEPROM phase, the X431 sends data to the CAS module’s memory. If the voltage drops below 12.0V even for a split second, the module can become corrupted. Replacing a CAS module costs well over $500, plus the cost of dealer coding. A $50 battery charger is cheap insurance. Always connect it.

For a deeper dive into battery management during diagnostics, check out our guide on [link to related guide on maintaining battery voltage during ECU programming].

FAQ

Can I program a used BMW G11/G12 key from another car?

No. Used keys are permanently linked to the previous vehicle’s CAS module. You must buy a new, virgin key fob that has never been programmed. Using a used key will result in a "Key Not Recognized" error every time.

Do I need the original key to program a new one with LAUNCH X431 IMMO Plus?

Not necessarily. However, you need the 20-digit security code. The X431 can retrieve this code from the car’s computer automatically, but this may not work for all CAS versions. If automatic retrieval fails, you will need to read the EEPROM chip directly, which does not require the original key.

How long does the key programming process take?

Typically 10 to 20 minutes, including tool setup and security code retrieval. If you need to read the EEPROM via chip removal, add another 15 minutes.

Will this affect my BMW warranty?

No. Using a professional diagnostic tool like the LAUNCH X431 to program a key is a non-invasive procedure and does not void the warranty. It only modifies the key storage in the CAS module. The dealer cannot detect that a third-party tool was used – the vehicle’s programming remains manufacturer-standard.

What if I lose all keys? Can the X431 still help?

Yes, but the process is more complex. You will need to remove the CAS module from the car and use the X431’s IMMO Plus EEPROM Adaptor to read the module’s data and reset the key memory. This requires technical expertise and may void module seals. If you are not comfortable removing and opening the CAS module, consider hiring a professional automotive locksmith.

For more details on all-keys-lost procedures, see our article on [link to related guide on BMW CAS module EEPROM reading].

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/