[Update] Fob reprogram failed on BMW 840ci - need key code

4454 views - Last reply: December 27, 2024
This topic is closed for new replies.

Where do they get the key code to program BMW 840ci keys at the dealer?

Hello! We've developed a VIN-based tool to help you get your key code for the BMW 840ci. Check it out here: VIN Key Code Generator.

Replies (3)

I think my BMW 840ci has the same issue. Good to know I'm not alone.

Anyone try this on a BMW 840ci with push-button start?

Been stuck with my BMW 840ci for weeks. This might be the fix.

Check the news !

Car Audio & Customization Show
🏎️ Local Meetup: Car Audio & Customization Show
Show off your ride and meet fellow car lovers

🗺️ Where: Fairgrounds Parking Lot
When: May 27 @ 10AM-4PM

Event features:
Car Audio Competition | Model Car Show

🔩 Forum Members: Post in the thread to reserve your spot! 👍

🧰 Off-Road Vehicle Build Day

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

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

📅 Skills Covered:
Torque specs | Bleeding procedures | Pad selection

🚙 May 17, 2026 at 10:00 AM (6-hour)

✨ Special discounts on tools for participants!

Workshop: Off-Road Vehicle Build Day
Street to Strip Tuning Workshop

🏁 Street to Strip Tuning Workshop

🔧 Instructor: Factory ECU Engineer Dr. Sophia Chen

💻 Workshop Includes:
• Common tuning mistake avoidance
• 4-hour intensive hands-on training
• Cam profiles | Compression ratios | Octane requirements

📈 Bonus: Live Q&A replay available

⏱️ Next Session: May 5, 2026 at 3:00 PM

Customize Your Tuning Focus:

🚀 Performance Mod Cost Estimator

Did you know? Proper tuning can add 20-30% more power from the same hardware

Vehicle Information

Modification Information

Additional Options

🔑 Car Key & Fob FAQ

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

Key Programming
Some vehicles allow DIY key programming using specific sequences (like turning ignition on/off with original keys). However, most modern cars require specialized equipment only locksmiths or dealers have. Check your owner's manual for your specific model.
Key Tip: Some locksmiths offer mobile key programming services
Key Programming
Most transponder keys and smart keys can be reprogrammed if they haven't been damaged. Basic mechanical-only keys (no chip) can't be reprogrammed - they must be physically cut to match your locks.
Key Tip: Newer cars often require dealer programming for first key replacement
Cost & Options
Locksmiths are typically 30-50% cheaper than dealerships for key replacement and programming. However, some newer models (especially luxury brands) may require dealer-only programming tools. Always get quotes from both.
Lost Keys
Yes, a skilled auto locksmith can extract the broken key and make a replacement. They can often do this without damaging the ignition cylinder. The new key will need programming if it has a transponder chip.
Lost Keys
Locksmiths or dealers can: 1) Decode your door or ignition lock to determine key cuts 2) Access your car's key code through manufacturer databases (with proof of ownership) 3) Program new transponder keys using diagnostic equipment.
Key Fact: Some luxury car keys can cost $800+ to replace at dealerships

🔑 KEY SERVICES CLASSIFIEDS

Key Fob Repair & Battery Replacement
$25+
Posted: Apr 26, 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: 795-738-7572
Immobilizer System Reset
$95+
Posted: Apr 21, 2026
Fix "key not detected" errors and immobilizer issues. Dealer-level diagnostic equipment. Can often repair without replacing entire system. Free estimates.
Call: 806-596-5977
Transponder Key Duplication
$65+
Posted: Apr 21, 2026
Get spare keys made before you lose yours! Cuts and programs most transponder keys on the spot. Cheaper than dealerships. 15+ years experience.
Call: 671-689-6941
Fleet Key Programming
Call
Posted: Apr 23, 2026
Commercial key services for businesses with multiple vehicles. Bulk discounts available. We can handle all your company cars, trucks, and fleet vehicles.
Call: 367-608-5540
Ads refreshed daily • Licensed professionals • Mobile services available

🔑 Upcoming Key & Immobilizer Services

Workshop
May 24, 2026

Dealer-Level Programming Workshop

by The Key Lab
Become certified in vehicle security systems with our intensive 2-day course
Seminar
May 20, 2026

Anti-Theft System Demonstration

by Mobile Key Tech
In-depth class covering push-to-start systems and proximity key programming techniques
Workshop
May 7, 2026

Smart Key Programming Class

by The Key Lab
Learn how to extract key codes from VIN numbers and decode vehicle security information
Seminar
May 17, 2026

Dealer-Level Programming Workshop

by Car Key Solutions
Learn how to extract key codes from VIN numbers and decode vehicle security information

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