[Solved] How to verify key code for Mash Five Hundred 400 is correct

4373 views - Last reply: April 28, 2025
This topic is closed for new replies.

How can I find my Mash Five Hundred 400's key code to program a new key?

Hello! We've developed a VIN-based tool to help you get your key code for the Mash Five Hundred 400. Check it out here: VIN Key Code Generator.

Replies (3)

My Mash Five Hundred 400's immobilizer is stuck. Hoping this helps.

I'm stuck trying to get the key code for my Mash Five Hundred 400, hope this helps.

This might finally help me unlock my Mash Five Hundred 400's key code.

Check the news !

Off-Road & 4x4 Jamboree
🚗 Local Meetup: Off-Road & 4x4 Jamboree
A casual meet for all makes and models

📍 Where: Brewery District
📅 When: May 13 @ 12AM-7PM

Event features:
Poker Run | Scavenger Hunt

🔧 Forum Members: Forum staff will be there - come say hi! 👋

🔧 Off-Road Vehicle Build Day

👨‍🔧 Instructors:
• Master Technician Carlos Rodriguez (20+ years experience)
• Custom Fabricator Mike 'Wrench' O'Connor

🛠️ Hands-On Activities:
• Paint correction demonstrations
• 4-hour intensive training
• Personal coaching

📝 Skills Covered:
Color matching | Clear coat application | Scratch repair

🚗 May 11, 2026 at 11:00 AM (4-hour)

🔥 Special discounts on tools for participants!

Workshop: Off-Road Vehicle Build Day
Forced Induction Tuning Lab

🏁 Forced Induction Tuning Lab

🔧 Instructor: Pro Drag Racer Jake 'The Snake' Reynolds

💻 Workshop Includes:
• Real-world case studies
• 4-hour intensive hands-on training
• Suspension geometry | Weight transfer | Damping rates

📈 Bonus: Custom tune file included

⏱️ Next Session: May 12, 2026 at 9:00 AM

Customize Your Tuning Focus:

🚀 Performance Mod Cost Estimator

Remember: More power means you'll need better brakes and tires

Vehicle Information

Modification Information

Additional Options

🔑 Car Key & Fob FAQ

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

Cost & Options
1) Always have at least 2 working keys 2) Get spares made before losing originals 3) Consider key insurance/add-on coverage 4) Store key codes safely 5) Use protective cases for smart keys 6) Program new keys before old ones fail completely.
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.
Cost & Options
Quality aftermarket keys work well for most vehicles at lower cost. However, some luxury brands use proprietary technology only available through dealers. For expensive cars, OEM may be worth the extra cost for reliability.
Key Tip: Always have at least two working keys to avoid expensive replacements
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.
Cost & Options
1) Always have at least 2 working keys 2) Get spares made before losing originals 3) Consider key insurance/add-on coverage 4) Store key codes safely 5) Use protective cases for smart keys 6) Program new keys before old ones fail completely.
Key Fact: Some insurance policies offer key replacement coverage

🔑 KEY SERVICES CLASSIFIEDS

Mobile Key Programming Service
$75+
Posted: Apr 28, 2026
Professional car key programming for most makes/models. We come to you! Transponder keys, fobs, and smart keys. Same-day service available. All work guaranteed.
Call: 899-711-3797
Smart Key Programming Special
$150
Posted: Apr 28, 2026
Push-to-start key replacement for Toyota, Honda, Nissan, Ford. Includes programming and testing. Limited time offer - normally $200+. Call for availability.
Call: 736-636-7181
Anti-Theft System Repair
$85+
Posted: Apr 25, 2026
Fixing security light issues, PATS systems, and ignition immobilizers. Proper diagnosis before repair. Most vehicles serviced same day. Warranty on all work.
Call: 539-306-7093
Vintage Car Key Restoration
$55+
Posted: Apr 20, 2026
Specializing in classic car keys (pre-1990). Can reproduce hard-to-find keys for antique vehicles. Museum-quality work for collector cars.
Call: 214-213-7050
Ads refreshed daily • Licensed professionals • Mobile services available

🔑 Upcoming Key & Immobilizer Services

Workshop
May 14, 2026

Transponder Key Tech Day

by Mobile Key Tech
Learn how to extract key codes from VIN numbers and decode vehicle security information
Workshop
May 26, 2026

Smart Key Programming Class

by Locksmith Pro
Learn dealer-level programming techniques normally only available at franchise shops
Seminar
May 7, 2026

Smart Key Programming Class

by Fob Fixers
Become certified in vehicle security systems with our intensive 2-day course
Workshop
May 10, 2026

Smart Key Programming Class

by Car Key Solutions
Solutions for when all keys are lost - from code pulling to immobilizer resets

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