Some Nissan Altima owners report experiencing starting issues indicated by a flashing yellow key light on the dashboard. This often points to a key recognition problem, which could stem from a faulty key fob or key sensor; trying a spare key may help identify the issue. Additionally, some owners encounter ignition system problems, including faulty starters or ignition switches, which can prevent the vehicle from starting. A weak or dead battery is another common culprit, so checking the battery charge and terminals for corrosion is advisable. Other potential causes reported include a damaged battery, defective alternator, worn timing belt, blocked filter, stuck steering wheel, bad distributor cap or rotor, engine failure, and faulty starter. If these troubleshooting steps do not resolve the issue, consulting a professional mechanic is recommended for further diagnosis and repair.