Check Engine Light: cruise control&EGR
 

Hi everyone... I just got my car back from the shop while they checked out my latest problem with my check engine light. Result:
1. Trouble code PO400 = EGR flow function...
performed electrical test program= connect test cable and socket box. #38.0 =pin 69-39=13.5V. (OK)
#38.1=pin 32-69=0.5 amp (OK) test vacuum=> 400 mbar (good)

2. code #CC009 repace cruise control module = erase trouble codes.

Anyway.. the tech erased the codes and the light is currently off. I was just wondering if I should be worried about anything happening? Our car has had so many EGR valve problems... does anyone know if there could be an underlying problem elsewhere in the system to cause the EGR valve to fail so often? The EGR was just replaced in march. Any insights on this will be appreciated!!!

Also... the cruise control module was also just replaced two years ago...1000 dollar job! These things keep occurring on this car... I know it's eight years old and some of the wire harnesses have been replaced due to deterioration. Anyhow, anyone, insights PLease?

~Manny

I believe the 94 C280's had an EGR recall. I would find out from a Mercedes dealer if it has been corrected. Not sure what the exact problem was with the EGR valve, but I know there was a recall. To find out if it applies to your car and maybe for more info, go to ALLDATA.com.
GOOD LUCK! ;)

David, thanks again buddy...

I know that there was a recall on the EGR valve on the car. They replaced it three times under warranty. I'm just wondering if the EGR valve has an updated part # and the MB dealer here is just giving us the old part again and again that's why it is constantly breaking. This is the second time after warranty that this thing broke... it cost 300 dollars just for the part!!! well... I'm just glad our babybenz is back in its stall..

:D

~manny

Look to my article about MB driveability in the DIY section. There is a picture there of where the real problem lies with EGR. ITS NOT THE VALVE. The picture is from a 1994 c280, although all 104 motors probably have the same problem.

The actual listing for the article is under Evaluating Engine Controls.

Steve...

CLEANING??? a simple yet understandable concept... lemme just get this correct... I dont need to remove the steel pipe that leads to the motor... all I have to do is run the speedo-wire through where the EGR was attached? How far do you push in the wire? I dont want to ruin anything... What about the rubber that attaches to the top of the egr? what does that do? What is that other valve right in front of the EGR... it looks somewhat like the egr valve...anything special to do to that?

Wow.. thanks very much... hehe.. now that I know that... I think I have a fully operational EGR valve or two sitting around the house right now:D

In the area of the EGR valve there is also the secondary air check valve. This system sets its own codes and is unrelated.

The speedo cable has to go from where the EGR attaches, to the rear of the engine, and then across the back, and then most of the way up the left side of the motor. This will be at least 40 inches (I'm guessing). I push the thing through by hand and mark the length with a dab of paint then I spin it against the stop till it moves significantly through. There is nothing that can be hurt. If the blockage isn't there the cable will reach the other side of the manifold and just ride there (you will not break through - at least not for a few weeks [bg])

To verify the activity of EGR place a vacuum hose to the nipple on the valve and suck on it while the engine is running. If the passage is clear the the engine will run significantly rough close to dying. Check before and after the cleaning for a comparison.

The hole doesn't have to be totally blocked to cause the light to come on.

You will need to make sure too that the last 1" or so of the cable you use to rod out the passage is flexible. The first time I did it the last inch or so of the cable was "fixed" and when I got to the last 90 bend it would not negotiate this bend. I thought I was "bottoming" out but after putting everything back together the light came on again shortly thereafter with the same egr code. I modified the end of the cable, re-rodded and now everything is fine.