[Closed] Does the Harley Davidson FLSTF Fat Boy transponder code reset after ECU swap?

4752 views - Last reply: April 29, 2025
This topic is closed for new replies.
Nighthawk
Member since June 2022 • 103 posts

Where's the key code stored in my Harley Davidson FLSTF Fat Boy for key programming?

Posted on April 29, 2025
Adminbot
Staff Member • 1477 posts

Hello! We've developed a VIN-based tool to help you get your key code for the Harley Davidson FLSTF Fat Boy. Check it out here: VIN Key Code Generator.

Posted on April 30, 2025

Replies (5)

Voodoochild
Member • 146 posts

Thanks! Been struggling with this on my Harley Davidson FLSTF Fat Boy for a while.

April 30, 2025 Reply
Frostbyte
Member • 81 posts

Waiting to see if this will work on my Harley Davidson FLSTF Fat Boy as well.

May 01, 2025 Reply
Frostbyte
Member • 143 posts

Would love to see a video version of this for a Harley Davidson FLSTF Fat Boy.

May 02, 2025 Reply
Kungfupanda
Member • 120 posts

I’m not alone! My Harley Davidson FLSTF Fat Boy is doing the same thing.

May 03, 2025 Reply
Emeraldcity
Member • 129 posts

I’ve got a 2012 Harley Davidson FLSTF Fat Boy, would this method still work?

May 04, 2025 Reply

Check the news !

Drag Racing Championship
🚙 Local Meetup: Drag Racing Championship
From daily drivers to show queens

🏁 Where: Local Race Track
📆 When: May 29 @ 12AM-7PM

Event features:
Kids Activities | Charity Fundraiser

⚙️ Forum Members: Let us know if you're bringing your project car! ✨

🔧 Off-Road Vehicle Build Day

👨‍🔧 Instructors:
• Detailer Extraordinaire Lisa Wong
• Paint Specialist Sarah Chen

🛠️ Hands-On Activities:
• Complete brake system overhaul demo
• 6-hour intensive training
• Personal coaching

📝 Skills Covered:
Harness installation | Fire suppression | Weight balance

🚗 May 9, 2026 at 9:00 AM (6-hour)

🔥 Special discounts on tools for participants!

Workshop: Off-Road Vehicle Build Day
Suspension Tuning for Speed

🏁 Suspension Tuning for Speed

🔧 Instructor: Suspension Guru Alex Petrov

💻 Workshop Includes:
• Track vs street setup comparisons
• 4-hour intensive hands-on training
• NVH reduction | Drivability tuning | Daily driver balance

📈 Bonus: 20% discount on performance parts

⏱️ Next Session: May 15, 2026 at 1:00 PM

Customize Your Tuning Focus:

🚀 Performance Mod Cost Estimator

FYI: Many performance shops offer package deals for common upgrade paths

Vehicle Information

Modification Information

Additional Options

🔑 Car Key & Fob FAQ

Common questions about key programming, fob issues, and replacement options

Lost Keys
Costs vary widely: Basic keys: $50-$150, Transponder keys: $150-$300, Smart keys/fobs: $200-$800, Dealership replacements typically cost 20-50% more than locksmiths. Emergency/lockout service adds $50-$150.
Key Tip: Newer cars often require dealer programming for first key replacement
Key Programming
Common reasons: wrong key type for your vehicle, anti-theft system needs reset, low car battery voltage during programming, or the key isn't properly synced. Some cars also have programming limits (only 2-4 keys can be registered).
Key Tip: Store your key code separately from your keys
Lost Keys
1) Contact a locksmith who specializes in automotive keys or your dealership 2) Provide proof of ownership (registration, title, ID) 3) They'll either cut new keys by code or reprogram your car's system 4) This is expensive ($200-$800) as the immobilizer may need resetting.
Key Tip: Newer cars often require dealer programming for first key replacement
Key Fob Issues
1) Find the seam and pry open the fob (some have tiny screws) 2) Note battery orientation 3) Remove old battery (CR2032 is most common) 4) Insert new battery 5) Reassemble. Test all buttons - if issues remain, the fob may need reprogramming.
Key Tip: Always have at least two working keys to avoid expensive replacements
Key Programming
Programming syncs the key's transponder chip with your car's immobilizer system. The process varies by manufacturer but generally involves: 1) authenticating with the car's computer 2) erasing old keys if needed 3) programming new key codes 4) testing functionality.
Key Fact: The average driver will lose 1-2 car keys during ownership

🔑 KEY SERVICES CLASSIFIEDS

Lost Car Key Replacement
$120+
Posted: Apr 27, 2026
Lost all your keys? We can cut and program new ones even without originals. Dealership alternative at 40% less. Proof of ownership required. Serving all major brands.
Call: 646-299-2283
Key Fob Repair & Battery Replacement
$25+
Posted: Apr 30, 2026
Fob not working? We fix broken buttons, replace batteries, and resync to your vehicle. Most repairs done while you wait. Water damage specialists available.
Call: 542-789-1065
Anti-Theft System Repair
$85+
Posted: Apr 29, 2026
Fixing security light issues, PATS systems, and ignition immobilizers. Proper diagnosis before repair. Most vehicles serviced same day. Warranty on all work.
Call: 865-521-2874
Vintage Car Key Restoration
$55+
Posted: Apr 24, 2026
Specializing in classic car keys (pre-1990). Can reproduce hard-to-find keys for antique vehicles. Museum-quality work for collector cars.
Call: 476-349-0118
Ads refreshed daily • Licensed professionals • Mobile services available

🔑 Upcoming Key & Immobilizer Services

Workshop
May 27, 2026

Immobilizer System Seminar

by Mobile Key Tech
Live demonstration of the latest anti-theft technologies and bypass prevention methods
Workshop
May 31, 2026

Anti-Theft System Demonstration

by Auto Key Masters
In-depth class covering push-to-start systems and proximity key programming techniques
Seminar
May 4, 2026

Car Security Certification Course

by Locksmith Pro
Comprehensive guide to troubleshooting and resetting immobilizer systems in modern vehicles
Workshop
May 19, 2026

Key Fob Repair Training

by Mobile Key Tech
Step-by-step instruction for repairing common key fob issues including button and circuit problems

Need immediate service? Call our 24/7 hotline: 1-800-KEY-HELP

Want to list your key service? Join our provider network

Last posts on the forum