Key problems
This is NOT to say that if your key doesn't have 221 on it, that you should rush to your dealer and cry to your service writer that you demand a new key. Thousands of non-221 keys will have no problems whatsoever throughout the entire life of the car. If a key malfunctions, THEN you need a new key. You know the old saying "If it ain't broke, don't fix it"? Same thing applies here.
Also, you may take delivery of a brand-new car that doesn't have a 221 key. There are still thousands and thousands of non-221 keys in the parts stock. 221 keys are being phased in. Eventually all keys will be the updated version.
QUESTION:
Does the smartkey start the engine if the battery in the smartkey is dead?
(I realize the remote door opening function won't work.)



