? for all you experts - w210 OM606 - PeachParts Mercedes-Benz Forum

JHZR2 · #1 06-27-2004, 11:45 PM

Hi,

My father has a 96 E300D, w210, non turbo 606 engine.

Has been a good car, gets 33 mpg, smooth, comfortable, with just one issue- a reoccurring check engine light.

When we first got the car, it was fine, but then after a while and a lot of driving, we managed to get a light. According to the free autozone scanner, it was 120 - throttle position sensor.

Replaced that. All was OK, burned out a glowplug, opened that up, found diesel around the injectors. Replaced all of them... no lights, smooth, good running, no issues. Then much to our suprice, the CEL came back on.

Took it to the dealer last week. Used their real MB scanner machine. They are saying that the computer spits out a lot of different codes. They say that sometimes the codes are bogus, thgey scan and get them, investigate, the part is fine, or they replace the part and the light comes back on.

Now theyve spent a week doing diagnosis. Ill bet the bill is way up there.

Ive heard talk from my father about a butterfly valve, and also about an idle air something. As I have a 123, I dont know enough about it, nor do I recall completely what the 'current' issues were.

I have to wonder if the logic in the ECU computer is perhaps faulty. That whatever its comparing to some value at the time, for if it should or shouldnt set the CEL, somehow goes wrong, and causes a hiccup and then it sets the CEL although nothing is wrong.

Could it be the computer is bad, and really nothing is wrong with the car? could a battery that is on the outs cause an issue like that? Maybe a faulty ground strap?

I am almost to the point that Im convinced that the car is fine and the CELs are bogus. The car runs perfectly, and all compnents of the car run perfectly, light or no light.

The dealer is stumped, apparently they are conferring with MBUSA or even Stuttgart tomorrow for assistance. The MB dealer is going with their best assistance, so am I. can anyone shed light on why the check engine light would keep coming on, often with completely different codes, often bogus?

Many thanks!

JMH

JHZR2 · #2 06-28-2004, 08:46 PM

anyone? any ideas?

Gilly · #3 06-28-2004, 09:07 PM

Quote:

can anyone shed light on why the check engine light would keep coming on, often with completely different codes, often bogus?

That sounds like a bad engine control module to me.

Most common cause for check engine light on this particular motor is a part in the intake manifold called the resonance flap (actually there are a pair of them. They get sticky and will set codes.

Gilly

Rick Miley · #4 06-29-2004, 10:09 AM

I know some engines had problems with wiring harnesses in the mid 90s. Was that sorted out by 96?

Gilly · #5 06-29-2004, 04:24 PM

Didn't really apply to the Diesels at all Rick. In my opinion it is an M104 problem, but I've heard of problems on the V8 and 12's.

Gilly

JHZR2 · #6 06-29-2004, 05:41 PM

Do you guys think that a bad battery could cause electrical problems causing the ECM to act funny and throw codes? I just ask because although the battery seems fine, its only 100 vs way over 1000 for anything else. I had a friend who actually had a problem like that, and Id hate to have my father spend a lot of $$$ at the dealer only to find out it was something stupid like that.

So in your opinion, could that be remotely possible?

thanks,

JMH