My chrysler 300m cranks but won't start.
If your engine is cranking, at least you know the starter and the ignition switch are working properly. This also means your battery should be good since it's cranking over your engine. First, I would check all your fuses. A simple fuse could cause your vehicle to not start. Next I would check the fuel. Make sure there is adequate fuel in the gas tank and that your fuel gauge is not faulty. If the above are all okay, then it could be electrical such as a bad coil or ECU. You should be able to visit your local auto supply store and have them test your vehicle for codes utilizing your vehicle's ODB II port under the dash. If all else fails, you may have to end up a local authorized mechanic or as a last resort, your local dealer.
You may want to check your camshaft sensor. If that goes bad, it can cause your engine crank but not start.
Search Chrysler 300M Questions
Chrysler 300M Experts