Peugeot 208 Key Replacement
It is better to leave the replacement of Peugeot keys 208 to auto locksmiths with the equipment and know-how. They will be able to make and program new keys much faster than a dealership would and at a lower cost.
If your key fob has stopped locking or unlocking your doors it could be due to a dead coin battery. There are other reasons for the key to be malfunctioning.
peugeot key fob in the coin compartment will stop your Peugeot 208 from locking or unlocking, and will not allow you to start the engine. If this is the case, you'll have to utilize the backup starting method that is detailed in the owner's manual of your vehicle.
Another reason why your 208 may not start is because the spark plugs are worn down. The spark plugs ignite the fuel to start the engine. However they are limited in their lifespan. If they are not used enough, they will eventually fail.
Luckily, there is an easy solution to this problem. The best way to solve this issue is to check the voltage of your car battery using a multimeter. If it's below 11.5 volts then you must replace it. It is also essential to clean the contacts of the battery if it has corrosion. This can be accomplished by removing the rubber covers off the two battery terminals, and then using a wirebrush to eliminate any damaged parts of the battery. After that, you need to connect the positive and negative pole cables.
Water Damage
If your 208 won't turn on and the battery is not running, then make sure whether the spark plugs are in good working order. It could be that they are just overly filthy, making them unable to spark. The spark plugs can be cleaned in the workshop.
Peugeot cars use a key with a transponder compatible with the immobiliser. This makes sure that only the correct key can start the engine. If the chip inside the Peugeot key is damaged, then it won't send the correct signal to the vehicle.
Water damage is a common cause of this issue. This is most common in colder climates. the vehicle may have been exposed to rain or snow. In this case, contact an experienced locksmith who will have the required tools and equipment to reprogram the key. They also have the most up-to-date technology and equipment needed to create the Peugeot 208 smart key. The process shouldn't take more than 15 minutes.
Contacts to the battery are not working properly.
Peugeot changed from the carbon-encased transponder chips to a brand new type of chip that incorporates electronic components on a circuit board. This new system works well when it's new, but over time the circuit boards begin to wear out and stop functioning correctly.
This could stop the immobiliser from working, so your vehicle won't be able to start. Contact a Peugeot specialist or a locksmith if this is the situation.
A common issue occurs when the battery inside the key fob starts to die. This causes the blade of the key to stop feeding into your lock. A locksmith for cars will replace the battery, and then cut a new key blade for you. This is a simple solution.
Faulty Receiver Module
It could be that the receiver module has a problem in the event that your Peugeot key fob stops working after being dropped on the floor, or exposed to a sudden storm or accidentally washed. The receiver is responsible for transmitting radio frequency signals to an on-board computer which controls the centralized locking system inside your Peugeot vehicle.
The key fob itself has rubber seals that block water from reaching the electronic chip inside. However, prolonged exposure to water could be able to penetrate these seals and cause damage to the chip. Submerging the key fob into sea water at the beach or throwing it into the pool can be especially damaging because of the high salt content.
If your Peugeot spare key fob doesn't work, you'll need to have the module replaced. This is only done by an Peugeot specialist or an expert auto locksmith. Peugeot keys are, unlike other vehicles, are secured by an immobilizer device. This requires the proper programming to allow the car to start. This is why you should only go with a knowledgeable Peugeot locksmith to handle the task of creating and programming an appropriate replacement.

Computer malfunctioning on-board
The on-board computer in your Peugeot is responsible for a variety of functions in your car including power windows and airbags. The on-board computer displays the code when something goes wrong. The code is stored in the system until the issue is fixed. This may require the on-board computers to be replaced.
The most frequent cause for the warning light for the airbag to turn on is corrosion or loose connections in the sensor. This could be due to wear and tear, aging, exposure to salt and moisture. This problem should be addressed as soon as you can, because an airbag malfunctioning could be dangerous in case of an accident.
If you see an error message stating that the card is not found on your Peugeot, the key battery in the key fob may be dead or weak. This can prevent the key fob from sending a signal to disable your vehicle's immobilizer. You can test this by pressing the unlock button on the key fob and then attempting to start your car. If this does not work the battery on the key is in need of replacement.