Q: My Mercedes 2009 CLS 550 will crank but wont start
My car started hard cranking 2 weeks ago after sitting in the garage for a week the next week it would not start at all checked the battery and fuses everything looks good
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First, try using an alternate key. If it starts easily with a different key, then the original key needs to be reprogrammed. If the problem persists with either key, then it could be the ignition switch or possible a fuel pump. If you would like help, have a qualified technician, like one from YourMechanic, diagnose the starting issue and guide with a repair.
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