Hi, I'm new here. I recently purchased a used 2009 x300. I was able to do 2 mows this year so far and today I experienced the same issue discussed here. I tried to do a cold start and it wouldn't start, I opened the hood to check if anything looked out of order and everything looked good at first glance so I put hood down and attempted to crank one more time. This time, the engine wouldn't even crank. Lights would come on and engine hours meter was also on but no crank. My neighbor helped me jump start with a car battery but no result. However, the engine hours meter now wouldn't come on at all. I took battery off and took to auto place to have it checked. The cold crank amp was coming up at 260 and the battery was measuring at 12.6 volts so it appears to be in good shape.
Just started to look at different posts online and this one is the one that describes my issue the closest. I've checked the 3 different fuses and they are all good, no cracks in them. I'm down to a couple of guesses (ECU, a starter relay or the starter selenoid). Can someone shed some light on what I could check on next before I have to reach out to the dreaded dealer for help? Thank you, any assitance is greatly appreciated!