e430 died

Bad key, try the spare.

Thanks, but if it were a bad key would it turn over. It did turn over but would not start.

In the car's fault memory. If no faults then check fuel delivery. Fuel pump, relay etc won't store a fault if they fail

The key has a coded logic that allows it to crank, but not stay running.

Thanks Gerald. Does that mean that the key may be bad or just need reprogrammed? Could it even be the battery?

It's likely gone bad, it's not a dead key battery issue. Try the spare key and see if it starts & runs. If so, then it's the key for sure.

This is the infamous "Voice of experience" speaking ;-) One of MB's illustrious dealers here in the USA managed to break my '00 E430 Sport's key after I'd driven the car over 200mi to them to get it serviced (no local dealer). They then tried to disavow any responsibility, etc., etc. (naturally). Having neglected to pack the little spare key, I was facing a

400 mile trip to home & back just over the stupid key. I looked at it and found they'd broken off the little clear red plastic tip on the thing. I found it on the floor near the service advisors desk, put it back on with some superglue (which they were reluctant to supply) banged it on his desk a few times and it worked. It then took them over three months to get me a replacement key ....so goes my MB "Experience"!

Look at the very end of the key unit, if the tip is badly scratched or broken it may have an effect. Also, try just banging it on something to see if it starts working again. Should be a warranty item if it has actually gone bad.

Erm, no it doesn't.

The drive authorisation process is as such:

Transponder in key is energised by RF transmission from EIS, this then powers the key to transmit its drive authorisation signal via the IR port (The batteries in your key are purely for locking/unlocking the vehicle, try dropping the batteries out of your key and see if you can still start the car). This signal is then passed via the EIS to the electronic steering lock, if the steering lock is happy with the information sent by the key (i.e. if it is the right key for the car) it will detach the steering lock and then send a signal back to the EIS switch informing that this has been done. The EIS will now allow the key to turn for cranking and will then send the drive authorisation signal to the engine control unit where it will again be checked and if it is correct the car will crank and run.

There are no conditions as you describe where the car will crank but not run due to key logic and if you understood the workings of the drive authorisation system you would see why this is not possible. Each component processes they key's signal and if it is happy with it then it will all work, if it isn't happy with it then you won't even get the steering lock off or be able to turn the key, you certainly won't be cranking the engine!

Thanks everyone for the help. It has not happened again and I am carrying my spare key and will see what happens. Maybe it was just a fluke and won't happen again. The dealer said that it was not likely that there is a sevice coded stored. I will let you all know if I find out something. Again, thanks.

In my case the broken key would unlock the column and the engine would crank and fire, but it would not stay running. It would rev to about 1000 rpm and die. After we repaired the little red end piece and banged on it it stayed working until the dealer was done with the servicing and I got it home.

Good luck & keep the spare key handy!