Peugeot 208 Key Replacement
Peugeot 208 key replacement should be left to experienced auto locksmiths with the right equipment and technical know-how. They can create and program new keys quicker than a dealership and at a lower price.
If the key fob stopped locking or unlocking your doors, it is likely due to a dead coin battery. There are other reasons the key could be malfunctioning.
Dead Coin Battery
A dead coin battery will stop your Peugeot 208 from locking or unlocking, and cannot start the engine. In this situation, you will need to choose the alternate method to start that is described in the owner's manual.
Another reason why your 208 might not start is that the spark plugs are been damaged. The spark plugs light the fuel to start the engine. They have a limited lifespan. If they aren't used enough and they fail, they'll eventually die.
Luckily, there's an easy solution for this problem. The best thing to do is to check the voltage of your car battery using a multimeter. If it is below 11.5 Volts it is time to replace it. It is also essential to clean the battery's contacts when it has corrosion. You can do this by lifting the rubber covers covering the two terminals of the battery and using a wire brush to remove any corroded components of the battery. Then, you should connect the cables for the positive and negative poles.
Water Damage
If your 208 doesn't start and the battery hasn't gone flat, you should inspect the spark plugs. You might find that they are dirty and they don't spark. The spark plugs can be cleaned in a workshop.
Peugeot automobiles use keys that are transponder-type and integrates with the car's immobiliser system. This ensures only the correct key is able to turn the engine. If the chip inside the Peugeot key is damaged then it will not send the correct signal to the vehicle.
This is a very common issue that is caused by water damage. This is a common issue in warmer climates where the vehicle has been exposed to rain or snow. If this is the case, get in touch with a reputable locksmith who has all the tools and equipment needed to change the key's programming. They will also have the latest technology and machinery needed to make the Peugeot smart key. The process should take no more than 15 minutes.
Contacts to the battery are not working properly.
Peugeot replaced the transponder chips by introducing a new model that utilizes electronic components mounted on a circuitboard. This new system works great when it's fresh, but as time passes, the circuit boards begin to deteriorate and stop working properly.
This can stop the immobiliser chip from activating and causing your car to not start. Contact an Peugeot specialist or a locksmith if this is the case.

Another common issue is when the battery in the key fob starts to die, this causes the key blade to stop feeding into the lock. A locksmith from your vehicle can replace the battery and cut a fresh blade for you, this is normally a quick fix.
Faulty Receiver Module
If your Peugeot key fob has stopped working after dropping it on the floor, or being exposed to a sudden downpour or accidentally washing it may be due to a defective receiver module. The receiver module is responsible for transmitting radio frequencies to the onboard computer that regulates the central locking system of your Peugeot vehicle.
replacement key for peugeot 207 has rubber seals that prevent water from getting to the chip inside. Water can damage the chip when exposed to the water for an extended period of period of. The high salt content in the pool or ocean waters could cause damage to the key fob when it is submerged.
If your Peugeot spare key fob stops working it is necessary to have the module replaced. This can only be performed by a professional auto locksmith or Peugeot specialist. In contrast to other vehicles, Peugeot keys are protected by an unique immobilizer system that requires the correct code to start the engine. This is why it is imperative that you should only trust an authorized Peugeot locksmith to design and program an alternative.
Computers with faulty on-board computers
The computer on the board of your Peugeot is responsible for many of the systems within your car, ranging from airbags to power windows. When something goes wrong in these systems, it will usually show a code that identifies the issue. The code is stored within the system and will stay there until the issue is fixed. This may require the on-board computers to be replaced.
The most frequent cause for the warning light for airbags to flash is corrosion or loose connections in the sensor. This could be due to wear and tear, age or exposure to salt and moisture. This issue must be addressed as soon as you can, since an airbag that is not functioning could pose danger in the event of an accident.
If your Peugeot is showing a card that is not being detected error then the key battery inside the key fob may be dead or weak. This will stop the key fob from sending a signal to deactivate the immobilizer in your vehicle. Test this by pressing the unlock key on the fob's key and then trying to start your car. If this does not work the battery on the key must be replaced.