So I got in my 190E to head to class today as I had a quiz and it cranked over then died immediately as soon as the key went back to the on position from the start position. Tried a few more times and nothing. I also noticed that my tachometer was not reading at all. I checked the fuses and rolled them but nothing changed. I checked the diagnostic light to see if there were any fault codes but had no response from the engine computer. I had someone pick me up to take me to get some furniture we had bought for my house and my friend who is a mechanic stopped by with my spare engine computer and changed it, but that changed nothing. I am currently suspecting the OVP is bad but it could possibly be a malfunctioning ignition switch or bad crank position sensor. The engine will run as long as the ignition is in the start position.

Any ideas?