How do you switch off the anti theft system on a peugeot 406?

To switch off the anti-theft system on a Peugeot 406, insert the key into the ignition and turn it to the "On" position without starting the engine. Wait for a few moments until the immobilizer light on the dashboard turns off, indicating that the system is disarmed. If the system continues to activate, consult the owner's manual for specific instructions or consider contacting a Peugeot dealership for assistance.