Mechanic Wiki: How to Program a Ram ProMaster Key (2020-2024) with LAUNCH X431 & Security Gateway Bypass

Step-by-step guide to program a new key for a 2020-2024 Ram ProMaster using a LAUNCH X431 scanner and Security Gateway Bypass. Save time and money with this DIY method.

Last Updated: June 16, 2026

Quick Answer

Yes, you can program a new key for a 2020–2024 Ram ProMaster using a LAUNCH X431 diagnostic scanner (like the X431 V+, PAD VII, or Pro3) together with a Security Gateway Bypass Module. After installing the bypass between the OBDII port and the vehicle harness, the X431 performs an Auto VIN scan and selects "Program Key" under the Immobilizer menu. The whole process takes about 10–15 minutes and saves you a trip to the dealership.

Understanding the 2020–2024 Ram ProMaster Key Programming Challenge

If you’ve tried plugging a standard OBD scanner into a modern Ram ProMaster, you already know the frustration: the tool gives a “Communication Error” or just won’t talk to the Body Control Module (BCM). That’s not a hardware failure — it’s by design.

Why the Security Gateway Exists

Starting with the 2018 model year, Fiat Chrysler Automobiles (now Stellantis) introduced a Security Gateway Module (SGM) on most vehicles. This module sits between the OBDII port and the main vehicle networks (CAN‑Bus). Its purpose is straightforward: block unauthorized aftermarket tools from writing or modifying critical data like key programming, ECU tuning, or BCM configurations.

Federal anti‑theft regulations pushed manufacturers to make vehicle electronics harder to hack. The downside? Even legitimate diagnostic tools — like your LAUNCH X431 — cannot directly communicate with the BCM or PCM on a 2020+ ProMaster without bypassing this gateway.

What Is a Security Gateway Bypass?

A security gateway bypass is a physical adapter that plugs between the factory OBDII connector and your scanner. It essentially “emulates” the factory gateway’s handshake protocol, granting the X431 the same access a dealer tool would have.

Important note: Installing a bypass module for the programming session does not void your factory warranty — as long as you remove it afterward. The bypass only passes signals; it doesn’t modify any vehicle software or hardware permanently.

Prerequisites: Tools and Preparation

Before you start, gather everything you need. Missing a single item can turn a 10‑minute job into an afternoon of frustration.

Required Hardware

Tool	Notes
LAUNCH X431 Scanner	Any model with the “Immobilizer” function: X431 V+, Pro3, PAD VII, etc.
Security Gateway Bypass Module	Must be compatible with Stellantis/FCA 12+8 pin config. Common brands: AutoAuth, Smart Safe, or OEM equivalent.
Blank Proximity Key	Use the correct FCC ID: M3N-40821302 for 2020–2021, M3N-40821303 for 2022–2024. Check the original fob’s lid for the ID.
Working Key	You need at least one existing key to enter programming mode on most ProMaster variants.

Software Check

Update your X431 to the latest firmware through LAUNCH Pro or the X431 app. Anything older than the 2023 software may lack the Stellantis SGW protocol.
Download the Chrysler/Stellantis diagnostic package under “Immobilizer.” The X431 will prompt you if it’s missing.

Step-by-Step Key Programming Process

Follow these steps in order. The X431 will guide you through most of it, but understanding each stage helps you troubleshoot if something goes wrong.

Step 1: Install the Security Gateway Bypass

Locate the OBDII port under the driver’s side dashboard, right next to the hood release.
Unplug the factory OBDII connector from the vehicle’s harness. You’ll see a rectangular 16‑pin connector.
Plug the bypass module into the vehicle’s harness — not into the scanner yet. The module should click firmly into place.
Plug your LAUNCH X431 scanner into the bypass module’s pass‑through port.
Turn the ignition ON (engine off). Watch the X431’s screen: you should see “Communication OK” or a green connection indicator. If not, the bypass isn’t seated correctly or your module may be incompatible with the 2023+ ProMaster (some need “SGW Bypass v2”).

Step 2: Connect and Identify the Vehicle

Open the X431 Diagnostics app on the scanner.
Select Diagnostics → Auto VIN Scan. The scanner will read the vehicle identification number automatically.
If Auto VIN fails, manually choose Ram → ProMaster → select the correct model year (2020–2024).
The system will then detect the BCM (Body Control Module) and PCM (Powertrain Control Module). This confirms that the bypass is working.

Step 3: Access the Immobilizer Menu

Navigate to Immobilizer or Anti-Theft System in the diagnostics list.
The X431 will ask: “Does this vehicle have a Gateway Module?” — select Yes. This tells the software that you already have the bypass installed.
From the submenu, choose Program Key or Add Key. (Avoid “Erase All Keys” unless you want to re‑program all your existing keys from scratch.)

Step 4: Enter Programming Mode

Depending on whether you have a working key or not, the procedure splits into two paths.

Method A (No working keys / lost all keys):
The scanner will ask for a 4‑digit security PIN.
Where to get it: This PIN is usually stamped on a card in the owner’s manual, or it can be retrieved from the vehicle’s radio or BCM via the X431’s “PIN Retrieval” feature (requires an internet connection). If that fails, contact a dealer or a locksmith who can pull the code from the VIN.
Method B (Adding a key with one working key present):
Insert the working key into the ignition, turn it to the RUN position, and follow the on‑screen prompts. The X431 will then authenticate the existing key and prepare to accept a new one.

Step 5: Write the New Key

Insert the new blank key into the ignition. Turn it to the RUN position (do not crank the engine).
Wait for the X431 to display: “Programming in progress… Do not remove key or scanner.” This usually takes between 30 and 60 seconds.
Once finished, the scanner will beep and show: “Key learned successfully.”

Step 6: Test All Functions

Remove the new key, then reinsert it and start the engine. It should crank and run normally.
Test the remote functions: lock, unlock, panic, and power liftgate (if equipped).
If the engine starts but the remote buttons don’t work, you may need to run a separate Remote Key Synchronization routine (sometimes called “Fob Sync” or “RKE Programming”) from the same Immobilizer menu. Some 2022+ ProMasters split the immobilizer and remote functions into different modules.

Troubleshooting Common Issues

Even with the right tools, things can sometimes go wrong. Here are the most frequent problems and how to fix them.

“Communication Error” or “No Vehicle Found”

Most likely cause: The bypass module isn’t connected to the vehicle side correctly. Double‑check that it’s between the harness and the scanner, not between the scanner and the bypass.

Fix: Reboot the X431 (hold the power button for 10 seconds) and reseat the bypass. On 2023+ ProMasters, make sure the bypass explicitly supports “SGW Bypass v2” — older modules may not work with the latest CAN‑Bus architecture.

“Security Access Denied” or “Invalid PIN”

Cause: The PIN you entered doesn’t match the one stored in the BCM, or the X431 failed to retrieve it.

Fix: Run the PIN Retrieval function again while connected to the internet. If that still fails, call LAUNCH support (they can help you generate the code from the VIN) or take the truck to a dealer for a code lookup. Free alternatives: some locksmiths can pull the PIN for a small fee.

Key Starts the Engine but Remote Doesn’t Work

Cause: On certain 2022+ ProMasters, the immobilizer (key chip) and the Radio Frequency (RF) hub are separate modules. Programming the key via the immobilizer doesn’t automatically teach the remote functions.

Fix: Return to the Immobilizer menu and select “Remote Key Programming” or “Fob Sync.” Follow the same procedure but with the scanner in the remote programming mode. It usually requires turning the ignition on and off in a specific sequence.

Only One Key Works After Programming

Cause: You accidentally selected “Erase All Keys” instead of “Add Key.” The X431 then replaced the entire key list, and only the newly programmed key is stored.

Fix: Re‑program both keys again, making sure to choose “Add Key” each time. When you add a second key, the scanner will prompt you to insert the first key, then the second.

Cost Comparison: DIY vs. Dealer

Method	Estimated Cost	Time
DIY (X431 + Bypass + Blank Key)	$50–$100 (if you already own the scanner)	15 minutes
Locksmith (with X431)	$120–$200	30 minutes
Dealership	$180–$300	1–2 hours (plus scheduling wait)

Note: If you don’t own a LAUNCH X431, you can rent one from AutoZone or a local tool library for about $50 per day. The bypass module pays for itself after one key replacement.

FAQ: Ram ProMaster Key Programming

Q: Can I program a key without the security gateway bypass?

A: No. Without the bypass, the LAUNCH X431 cannot talk to the BCM on 2020–2024 ProMasters. The bypass is mandatory for any programming or immobilizer work.

Q: Do I need two working keys to program a third?

A: No. The LAUNCH X431 can add a key even if you only have one working key. You just need at least one working key to enter the programming routine. (If you have zero keys, you’ll need to retrieve the security PIN first.)

Q: What blank key do I buy?

A: Look for a Stellantis/Mopar “Smart Proximity Key” with the correct FCC ID. For 2020–2021 it’s M3N-40821302; for 2022–2024 it’s M3N-40821303. Avoid cheap generic fobs without the proper antenna frequency — they won’t sync reliably.

Q: Does the bypass module drain my battery?

A: No. The bypass only draws a tiny current when the scanner is actively communicating. It won’t drain the battery if left plugged in overnight, though I still recommend unplugging it after you’re done, just to be safe.

Q: Will this work for a 2019 Ram ProMaster?

A: Yes. The 2019 model also uses the Security Gateway, and the process is identical. For 2017 and older ProMasters, you do not need the bypass module — the X431 can connect directly.

Q: Can I use a different scanner (e.g., Autel, Snap-On)?

A: The steps are similar, but menu names and required passwords may differ. The LAUNCH X431 is widely considered the most “DIY‑friendly” tool for Mopar key programming because of its straightforward Immobilizer interface and built‑in PIN retrieval. If you use an Autel, expect a slightly different workflow.

Is the DIY Route Worth It?

Programming a key on a 2020–2024 Ram ProMaster comes down to having the right two tools: a LAUNCH X431 and a Security Gateway Bypass. The bypass module costs between $30 and $60 — a one‑time purchase that saves you over $150 compared to a dealership visit. The scanner itself, if you don’t own one, can be rented or borrowed.

Before you start, double‑check your bypass module’s compatibility with your specific model year (especially the 2023–2024 models that need “v2”). Keep your original working key safe as a backup, and always perform the test steps before closing up the dashboard.

Got stuck? Drop your specific error code in the comments below, or contact LAUNCH technical support — they offer free remote assistance for scanner users. For more background on choosing the right bypass module, check out our guide on [link to guide on choosing a security gateway bypass]. If you’re shopping for a new diagnostic tool, see our [link to LAUNCH X431 review].

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/