The document discusses potential reasons for immobilizer issues in BMW X5 vehicles from certified mechanics in Chattanooga. Key problems include a deformed key that cannot communicate with the car, issues with the transponder coil preventing communication between the key and immobilizer, and battery or fuse problems that can disrupt the electric circuit and cause immobilizer malfunctions. The immobilizer is an important anti-theft feature, so owners experiencing issues should take their BMW to a certified repair shop for evaluation and fixing of potential underlying problems.