Start Error
 

I own a 2002 ML320. I have a "start error", the engine will not turn over with the original key in the ignition at position 3 :( . I also have a spare key that I'm sure was not programmed that I tried to start the car with that probably created the error. I have since tried to start the car with the original key (after the spare) but still get the same error. So, I "shorted" the K8 relay and the starter will turn over the engine (so I have ruled out a bad starter or solenoid). Not sure that there is anything more I can do to diagnose the problem (without spending thousands at the dealer). I'm open to suggestions though.

So I think my only "economic" solution is to go to the junkyard and purchase a new ignition "system", with a key included. Can someone tell me all the components I will need to get from the junkyard car to resolve this start error? I am guessing I at least need the immobilizer, DAS module, ignition switch and key. Anything else?

Otherwise, I am not willing to spend the thousands of dollars that the dealer would want to "repair" and program my current car.

http://www.peachparts.com/shopforum/tech-help/380512-1998-w140-s500-no-start-start-error-displayed-odometer.html

Here's a similar issues on a 98 S=class.

So, after reading that referenced post above, his solution was a "fuse" on the S500. Does my 2002 W163 have a fuse related to the DAS/ignition system? I thought the only "fuse" was the K8 relay. Am I mistaken?

The K8 relay is operated by the engine ECU but its the final step of the start process sequence and there are quite a few things that have to happen before the ECU issues the OK to operate the starter. Being able to activate the starter with a hot-wire of K8 would verify the starter motor is working but nothing else in the start sequence of events.

I'm not very familiar with the W163 particulars but I think the ECU gets instructions to operate the starter from the Drive Authorization system. There are more than a few 'moving parts' to the Mercedes DAS system and they particulars change depending on years and versions of DAS used.

https://www.benzworld.org/threads/everything-you-always-wanted-to-know-about-das.1245088/

My cousins issue with S-class was a fuse that provided power to the DAS module - this interrupted the whole validate/start sequence.

Your ML seems to have something called an 'All activity module' denoted as N/10 in the Star Wiring diagrams that provides this function.