After a few weeks of running very poorly, my local service shop has informed me that after 3 days of looking and many tests they have narrowed my cars problem to a faulty ... CIS Brain they called it.

The part number on the current part is 008 545 8132
My MB Dealer tells me that the new number is 011 545 2732

I'm in kind of a pinch here...The only way (they tell me) to test the car and see if that indeed is the problem is with another ECU. But, these parts are VERY expensive and once purchased you can't return them.

This is a 1990 300E 3.0

Is there now way to remove the ECU examine it clean it and maybe repair it?

I don't want to loose my 300, but these repairs are eating me alive!

Thanks
Steve

Its very UNcommon for the CIS-E controller to go bad, but it does happen. The car runs warm very well without the controller so be sure the problem goes away in such conditions.

The part is so durable that they are dirt cheap from any junk yard that doesn't crucsh them (amazing the electronic parts some yards just throw away). Try www.car-part.com to search a used part

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

For what it's worth..

I had some very strange things happening in my OTM (Other Than Mercedes) car.
The shop told me it was a malfunctioning ECU and that it would cost me $1200 to replace.

I decided to have a look myself.
It turned out that several of the contact points in the multi-pinned plug were oxidated. And after a cleaning with alcohol, everything worked perfectly. -And here 2 years later, it still does..

It won't cost you a dime to try it..

Freestyler

__________________
Never criticize someone until you've walked a mile in his shoes. That way, when you do, you're a mile away -and you have his shoes!


'86 300E optically converted to '95 E300 (Sold)
-Blauschwarz on silver
-Black leather
-17" AMG & 15" AMG for winter

Thanks for the encouraging words guys....I'll get my car back tomorrow evening and then get after it from there.

Sometimes.....(I know this may seem offensive to some) but sometimes I get the feeling that my service technician looks for the "easy" fix.

I know that having to pay for these expensive parts, makes me much more motivated than he to find the least expensive route to a good solution.

Thanks again for your suggestions, I'll let you know what happens.

Steve

Diagnosing control units is the worst of business, but I would take my car to a tech who stands by his diagnostics.

If I diagnose a control unit and I install it and it doesn't fix the car the part comes back off and becomes inventory. If I diagnose a control unit and you replace it and its not the problem it becomes your inventory. Depending upon risk the amount of testing changes.

For a car like yours I would monitor two outputs: EHA current and Idle speed valve current. if they were wrong and the basics to the controller were right I would make the call, I would get a used controller (actually I probably already would have one) and confirm the diagnosis. The customer would pay less than half the price of new.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve,

Are there any houses for sale not far from you? I think it's time for me to move so that I am within range of your shop.

Merry Christmas,