Smart Fortwo W451 Key Replacement (2007-2014)
Intro
Built between 2007 and 2014, the second-generation Fortwo came with a 3-button remote. The original key has a round black head and a fixed blade, and the chip inside it is an ID46. Flip-key replacements carry that same chip and work on the same frequency. When yours is lost, broken or has stopped working, Kamran can cut and programme a new one at your car.
Which key does the Fortwo W451 use?
The W451's original key is a black plastic, round-headed remote with three buttons — lock, unlock and rear window open. Inside it sits an ID46 chip (PCF7941), working on 433MHz in the UK; some markets use 315MHz, so the registration is checked first. The blade is cut to the car. Flip-key replacements carry that same chip and work on the same frequency. No battery type is given on this page yet. The key's part numbers are 4518203797 and KR55WK45144.
Note: the original W451 key is a fixed-blade round-head remote, not a flip key. The flip-key version is the replacement form, and the link to the remote flip key page below is that replacement form.
Year and generation range
The W451 followed the W450 City-Coupe and was replaced by the W453 in 2014. It is a two-seat city car, sold as a coupe and a cabrio. The Pure, Passion and Pulse trims all used the same key.
Lost all keys vs spare key
A lost key and a spare key are two different jobs. When every key is gone, the new one is made from the car's own data. When you still have one working key, the spare is copied from it and programmed next to it. Either way the work is done at the car, and ownership is proved first.
How the key is programmed
Programming a W451 key means connecting a diagnostic scan tool to the car. That needs specialist equipment — it cannot be done with consumer tools, and it cannot be done at home. The exact tool Kamran uses is confirmed by him.
Who does the work
Kamran does this work himself. He is a Smart key technician, and he has 15 years' experience with these keys.
What affects the price
No price is published on this page yet. The quote comes on the call, and it depends on the job.
Whether every key is lost or you still have one changes the job. So does the key version — the original fixed-blade remote or the replacement flip-key version. A blade that must be cut is part of the quote, and so is the programming. Ring 07367 634032 with your registration number and Kamran will give you a fixed quote before booking.
How long it takes
How long a W451 job takes is not given here yet. Kamran will confirm it when you ring, once he knows the model and the job.
Proof of ownership
Before any work starts, Kamran checks that the car is yours. Which documents he needs is confirmed on the call — nothing is made until that check is done.
Common problems for the Fortwo W451
Four faults turn up most often on the W451. The key stops unlocking the car, or its buttons stop responding. The fob battery goes flat. Or the car stops detecting the key at all. Check the battery first if the key has gone dead — no battery type is given on this page yet. If a fresh battery does not fix the fob, the fault may be in the buttons, the circuit board or the chip.
Related models
- Smart Fortwo W450 key replacement
- Smart Fortwo W453 key replacement
- Smart EQ Fortwo key replacement
Call to action
Call 07367 634032 now — open 24 hours, mobile service across the West Midlands.
Frequently asked questions
What key does a Smart Fortwo W451 use?
The W451 uses a 3-button remote key with an ID46 transponder chip, on 433MHz. The original key has a round black head and a fixed blade; replacement flip-key versions use the same chip and frequency. The blade is cut to your car and the key is programmed with a diagnostic scan tool. Confirm the key with Kamran on the call.
I have lost all my Fortwo W451 keys. Can you still make one?
Yes. If every key is lost, Kamran can still make a new W451 key at your car, as long as ownership is proved first. Call 07367 634032 with your registration number and confirm the documents you need before booking. The new key is cut and programmed at your location, then tested in the car before Kamran leaves.
Can I programme a Fortwo W451 key myself?
No. A W451 key needs a diagnostic scan tool and specialist equipment, and suppliers state programming is only possible with specialist equipment. It cannot be done with consumer tools or at home. Kamran programmes the key at your car, then tests it before leaving. The exact tool he uses is confirmed by him.
What battery does a Fortwo W451 key fob take?
The battery type depends on the key your W451 has, so it is confirmed on the call. Call Kamran on 07367 634032 with your registration number and he will tell you which battery your fob takes. If a new battery does not fix the fob, the buttons, circuit board or chip may be at fault.
How much does a Fortwo W451 key cost?
The price is confirmed on the call, because it depends on whether you have a working key, which key version you need, and whether a blade must be cut. No prices are published here yet. Call 07367 634032 with your registration number and Kamran will give you a fixed quote before booking.
Related pages
Lost your Smart key? Call now.
Open 24 hours — mobile Smart car key replacement at your car in Birmingham, West Midlands, UK. No towing, no dealer visit.