W210 Electronics Nightmare
 

Trolling Craigslist, found this:

1998 mercedes turbo diesel, parts car,

So thought I'd call just out of curiosity. Car has 220k, all mechanicals are good, interior and exterior are fine. Owner got in the car one day and it just wouldn't go. I'm forgetting some of this details, but this began an odyssey of trying to figure out what's wrong with the car's electronics/computers. He's spent months and months investigating, has had various indie mechanics with MB experience look at it, and has come to the conclusion that the only recourse is to take it to the dealer and have MB start replacing and reprogramming various modules....to the tune of thousands of dollars. So he's done with it.

Now, maybe he and his coterie of mechanics aren't the best diagnosticians. Still, it's a little sobering that the electronics could go out like that and resist diagnosis and repair to that extent.

Not really a very compelling indictment of computers without more information about the technical abilities of the people doing the diagnosis.

I will agree that it's very difficult to do any meaningful troubleshooting on these newer cars without access to a Star Diagnosis machine or a clone version available on e-bay.

If you do have access to such a tool its quite eye-opening to see what can be diagnosed without even picking up a wrench.

As a quick aside why would someone buy a car that didn't come with a title? How in the world could you deal with the issue that it may be stolen?

Its from 1,500 miles away and he doesn't have a title, that's not a red flag or anything.

In RI cars 10 years and older don't have titles....assume some other states as well.

I didn't catch that part..... just drove it up from Florida? and no title? I wonder if he was in a high speed pursuit up I95:D Well, maybe a medium speed pursuit?

If I was looking for a cheap W210 maybe I'd take a shot at the $1k level but without a title? No way, again how does someone get into circumstances where they posses a car but they don't have access to the title?

If the K40 relay faults, no codes will get set. Makes one wonder if any of the guys mechanics have ever heard of that relay.....

Auto electric can develop really difficult problems to sort out sometimes. Something as simple as taking or giving someone a boost can unleash a nighmare.

Does not happen often but the potential is always there.

Again, no details about what's been done to try to correct the problem, no details on the symptoms makes it impossible to diagnose. Do you have access to the car's wiring diagrams? Have you gone through the OBD2 port yet? Have you looked at any trouble codes or sensor data from the CCU?

I owned a w210 from new. Among the most troublesome cars I've ever owned. HVAC reliably blew cold from November through March, hot from April through October. Replaced lots of electronic stuff, mechanicals, and it rusted like an old tin can. Fortunately, I took the extended warranty from, so the dealer gave it lots of love. It did look great, high above the traffic on a flatbed. It's a generation that you should skip.

Florida is not one of those states.

Got some clarity....guy bought it from auction two years ago. Says "it has always had electrical issues." Can you say FLOOD?

Needless to say, this car's unhappy fate no longer concerns me as an indicator of W210 electrical woes.

As to the title, apparently he's in some sort of legal dispute with the lien holder. (Who knew...I guess people that buy cars at auction sometimes have loans).

Worth somebody pursuing as a parts car...but not I.

Interesting to see the wide variety of W210 experiences people have. While everyone acknowledges the rust issues, lots of long-term owners have no other complaints. I'm only 7k miles into mine....so we'll see.

Yeah. Which means it can be repossessed from the future new owner, despite that oh-so-helpful bill of sale...

Steering clear is a good idea, unless it's strictly being parted, never driven again.

The rust problem is manageable if you periodically go over the whole car and fix every stone chip. This includes the underside, suspension hard points, inside fenders and bumpers, water drains at the bottom of the doors and areas underneath the door and trunk seals. Even California cars are susceptible. I wouldn't own a 210 one of these cars if I lived in an area where they use road salt.
http://www.peachparts.com/shopforum/3288881-post19.html

Back to the original point, assuming its not a flood car

Bad K40 relay
CAN bus shorted or disconnected

Remember all the power train controls talk over the engine CAN bus.
There is a second CAN bus for the body systems.
They meet at the instrument cluster.