I have a problem with starting my SL55 though I can imagine it could apply to any R230. The car starts perfectly on Keyless Go. Using the key, it can be inserted and turned but when I turn the key to start the car, most of the time, the engine just grunts; other times it starts fine. I’ve traced the problem to the drive to the start relay from the engine ECU. When the engine starts normally, the relay is energised for a couple of seconds. When the fault occurs, it’s energised as normal and then gives up after about 1/10 second. The grunt is the sound of the starter motor being switched on and almost immediately off. The dealer wants me to spend £1000 to replace the shift lever. The diagnostics are saying a drive authorisation message is not being received, but it sounds more like educated guess work and no one can offer any explanation why it is then ok with Keyless Go. Any thoughts anyone?