I would be willing to bet there is a fault with the "start authorization" of the EIS ignition switch. Do you have a different
Key? If so, try using it for a while and see if the problem goes away. When the dealer checked the car, did they find any DAS
codes stored in the system?
Some times the transponder chip in the key will give you real grief and then work all of a sudden.


The L5 crank position sensor is known to cause issues with starting or lack there of. The connector can get moisture in them
and cause trouble. The flywheels also need special grease in some cases with starting issues.
The starter will nick the ring gear on start attempt and cause it to vibrate, these vibrations are picked up by the crank sensor and
recognized as about 14-1500 rpm. this causes the starter to cancel. Usually, the tach will jump or bilp when this happens.

Good Luck and sorry your dealer has issues.
DR.D