What I was trying to say was that if the diagnostic system relies on codes in an on-board computer, how can you rely on the codes if that computer is malfunctioning? Maintaining an EFI system is only easy if the on-board computer is still working OK.

And don't think that the manufacturers are going to keep stocking replacement computers beyond the required 7 years. My daughters 1989 Ford Ranger had its OBC fried by a well meaning jerk who crossed the cables while trying to jump start the truck. This was 3 years ago and Ford could not have supplied me with a replacement computer even if I had wanted to ante up the $600 asking price. It was no longer made AND there was no later model replacement that would work, due to firmware differences. I ended up having to scour the wrecking yards to find one with exactly the same firmware code.

That brings up a whole new nightmare scenario. Manufacturers change the software and firmware all the time to correct bugs or because different features are supported. Who do you think is going to support and maintain that firmware and software database after the warranty period has expired? Even for a simple '89 Ford Ranger there were different firmware/software combinations depending on Engine, Transmission, 2WD or 4WD, A/C or no A/C, oh and it changed according to certain date codes as well. :eek: Can you imagine the permutations for a BMW 7 series that has nine, count them 9, seperate computers!!!!

Like I said Hi-Tech is fine for as long as the warranty is in place, but whunter hit the nail on the head, built-in obsolesence is a reality for most consumer goods and it is fast heading that way for cars. Nobody bothers to fix a $50 VCR when the tech charges $55/hour + parts but 20 years ago when they cost $300 nobody would dream of throwing one away without trying to get it fixed. 10 year old cars are being written off today because the airbags deployed in a minor fender bender and it isn't economic to replace them. In 15 years time older cars with obsolete sophisticated computer systems are heading down the same path. :(

I know the Ford and GM dealers don't have parts for cars older than 7 yrs old. However, at this point, I still have faith that MB will have the parts past 7 yrs seeing as how you can get a part for a 30 yo car. Or is my faith misplaced?

fwiw, the majority of MB's control units that are in their cars now are upgradeable.

Thats good to hear.
I do have a LOT more faith in M-B supporting their products beyond the required 7 years, but my experience in the electronics industry has proved that you are ultimately in the hands of the "chip" manufacturers who obsolete chips at will and often without warning. Sometimes there is a suitable replacement but not always. Without these chips you cannot make the replacement parts and probably could not justify a re-design for an older unit. Unless they have guaranteed component sources, M-B (and everybody else) will face the same problem. I hope I'm wrong, but experience tells me otherwise.

I love the security, comfort and convenience that much of the new car technology offers, I am just not convinced it will be as serviceable over the long term.

People are always critical of new stuff, especially when the old stuff worked well enough for them that they see no reason for a change. However, the engineers at Mercedes-Benz aren't stupid while everyone else is intelligent. Of course economic conditions and business strategies come into play in determining what is produced but still these engineers aren't stupid.

I'll take any newer MB over an old one any day. I just have to do my research properly to determine if it is a car I want to own without a warranty or not, and also to determine what the car's general weaknesses are and be prepared for them. The convenience features and excellent crash structures / safety airbags that these cars have these days are incredibly effective in doing what they were made to accomplish. You just can't beat that.

Real question
 

The real question is whether or not the average DIY'er can fix it himself/herself without needing the extended warranty, high payments, high property taxes and his or her own engineering degree from an acredited university.

When I was in architecture school the first year they made us learn the KISS principle. We had to repeat it over and over. "Keep it simple stupid." I have seen the old Mercedes cars smashed to pieces without air bags and electronic stuff and other than the w140 Princess Diana got buggered up in over in France, I have seen most people walk away.

If I can afford to pay all those high payments, taxes etc and can afford to only touch a wrench when I want to not because I have to, I'd go for it. I'm not saying the older cars aren't safe, if that were the case I would never have purchased any of them. I saw crash test videos of W126s with and without airbags and both performed very well. They were best in their day and today they still rank as average. The new cars are just much, much better. Plus, you can't get many of the convenience features (what people call "gadgets") on the older cars. I happen to like those features so they are a plus to get a new car for me.

You will need a scantool for the engine part and as far as the other computers go, you are probably stuck there.

I have gotten T-boned by a smaller car right in the driver side. My 202 driver seat was about a foot wide at the end of the day. Side airbag deployed but the others didn't, as it should be. Worked out fine and I walked away with a couple of fractures.

:stunned: Now apply that progressive thinking to alternative fuels and you will be logically consistent!

If I had the money I would have a 2006 S400 CDI sitting in my drive way. And I would never get my hands dirty or even have to pop the hood to check the oil! :D Sounds pretty good to me. I'd keep the SDL for weekend fun.

I wouldn't buy the new CDI either. I will give it a chance but someone has to prove it first and that someone won't be me. IOW, not on my dime. Remember the 98 M-class? I generally don't buy an item the day it comes out. I'll give it a chance before dismissal but not with me as the test subject. I don't want to be cutting edge but I will not be way in the back either.

As to alternative fuels, they reduce emmissions in fleets which is wonderful for them. They have yet to prove it improves MY bottom line. IOW, based on MY concerns, SHOW ME THE MONEY. My 99 E300 has shown to improve MY bottom line when I tally up the fuel bills. Now, if the maintenance is about the same for that car as other cars of it's type, it will decrease MY car expenditure. I used B2 because by going 4 miles out of my way, I saved 10 cents a gal. That comes to about $4 a week. That is an alternative I can live with. If I had to go 30 miles out of my way, that is a whole different story. My first concern is cost. It costs more than regular diesel and the returns have yet to be shown in the lowered maintenance bills for passenger cars to offset the higher cost. Fleets, maybe so with their consumption levels being much higher and the cost of their maintenance, it might work out. Passenger cars, not yet. If it is going to be billed as an alternative, make it an alternative. IOW, advailability and price has to be about the same. I'll allow for a higher price IF I can see returns in the maintenance department to offset the higher cost. Like I said before, price it similarly and make it just as advailable and that will be a true alternative.

I'm generally in favor of computers in cars, since I'm a 'computers in everything else' sort of guy (hell, even my rebuilt vintage bikes have computer controlled lighting now).

However, I think for it to be something that is easy to deal with, some level of standardization is necessary. OBD codes were a good step, so you don't have to have 10 scanners to work on 10 different models. However, in the end, some sort of standard 'sensor / control system interface' computing standard needs to be agreed upon. Just like the standards for your home computer. AT, ATX, Mini-ATX etc for motherboard form factor, 3.5", 5 1/4", 2.5" standard drive form factors, and better yet, the interface standards like ATA, Serial ATA, SCSI, etc. PC100, PC2100 for memory, and so on.

If manufacturers could agree on things like this, then the hassles of a computer control would not be so bad. Your diagnostic scanner wouldn't have to just expect the onboard computer to be functioning, since it could be a computer of its own, you could have a big terminal block that all the sensors come to, then you just plug your diagnostic computer into that terminal block, bypassing the onboard computer completely. Since you've got a standard communication protocol for all your sensors, the diagnostic computer can directly look at the problem. If the onboard and diagnostic computers show different results, you know the onboard computer is dead, in which case you install a generic computer and load it with the software for your particular model of car.

It would be just like working on a home PC.

Problem is, car companies don't think of their cars as computers, they think of them as car parts. People are out there R&R'ing their control computers, which is silly. Do you R&R your home PC when the mouse stops working? No, you just swap out the mouse, or better yet, test the mouse with a different computer to see if its a mouse problem or a computer problem. But without standards, we can't do that sort of thing.

Anyway... Computers in cars can be very good, digital control can be 1000X more flexible than mechanical control, and can improve every aspect of an engine's performance, but it has to be done right, otherwise its a major maintainence hassle.

peace,
sam