Recently the aforementioned key has started to act up. It locks and unlocks the doors just fine, but does crazy things when used in the ignition. Sometimes a CEL comes on. Yesterday I started the car and backed out of the garage, and put it in Park. But then I couldn't get it out of Park.

The other 2 keys I have work fine. I'm surprised because I would expect a malfunctioning key to fail to start the car-I don't know why the car would change its mind about the key after it is running.

Oh well.

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1996 C280 289K Traded
1997 E420 167K Traded
2001 S430 240K Traded
2010 E550 4matic 80K
2000 GMC Jimmy 198K Gone to Boneyard
2003 Camry LE 196K
2011 Mazda3 i Sport 31K