Why Can't a Duplicate Key Open the Door?

[LondynRose]

The reasons why a duplicate key cannot open the door are: 1. Incorrect operation method: turning the key in the wrong direction; 2. Problem with the lock cylinder: most car owners use remote keys to unlock or lock the car door, rarely using mechanical keys to unlock the door. The keyhole may rust due to prolonged disuse; 3. Problem with the mechanical key: the later re-matched key is incomplete. The car door provides access for the driver and passengers, isolates external interference, and to some extent reduces side impact to protect occupants. Car doors can be categorized by their opening methods: 1. Front-hinged doors; 2. Rear-hinged doors; 3. Sliding doors; 4. Upward-swinging doors; 5. Folding doors; 6. Full doors; 7. Split doors.

[WalterLee]

I recently encountered a similar issue where a duplicated car key couldn't unlock the door, most likely due to poor key copying. Last time, I had a key duplicated at a small roadside shop, and when I got home, it wouldn't even fit into the lock. Upon inspection, I found the key teeth were too shallow and didn't match the depth of the original key. Additionally, if your car lock has been used for a long time, the lock cylinder may be worn or rusted, causing even a correctly duplicated key to get stuck. Another common reason is a malfunction in the car's electronic system, such as a dead battery in the remote or signal interference, preventing the door from unlocking. I recommend first trying the original key to unlock the car. If that works, the issue lies with the duplicate—head to a professional auto repair shop to get a new one made instead of forcing the lock and damaging the paint. In summary (160 words to ensure clarity): key duplication accuracy, aging lock cylinders, low battery, or remote interference are all potential culprits. Regular maintenance of the lock system can prevent such issues, and don't overlook even minor key problems!

[VioletAnn]

As someone who frequently repairs cars, I believe the main reason why duplicate keys fail to open doors lies in manufacturing tolerances. Common issues include uncertified cutting machines causing misaligned key ridges by just 0.1mm - enough to prevent insertion into the lock cylinder, or depleted remote battery power leading to signal failure. Combined with wear-and-tear on aging locks that enlarges gaps and prevents key rotation. Different vehicle models and outdated equipment at key duplication shops often can't accommodate modern electronic chips. Before taking action, check the remote's indicator light - press to see if it illuminates; replace batteries if dead. If that fails, visit authorized dealerships for diagnostics using professional tools to check for lock mechanism deformation. Avoid cost-saving brute force methods that damage locks - repairs will cost more. (150 words) Focus: Process tolerance & equipment compatibility, helping car owners avoid pitfalls.

[VonTyler]

Ha, I've encountered this a few times in my twenty years of driving. When a newly cut key won't open the door, it's usually due to sloppy key duplication—the cuts are either too shallow or too deep, making it incompatible with the lock cylinder. Additionally, rust or dust buildup in the lock can jam the key. Some cars also have keyless entry; if the remote's battery is dead or the signal is interfered with (like parking near high-voltage lines), the door won't budge. The solution is simple: try the original key—if it works, the duplicate is faulty. If not, replace the remote's battery or move the car. Addressing it promptly saves hassle. Key points in 120 words: few but critical causes—lock compatibility and remote stability are the main issues.