bsvensson

Hi guys,

I need your help again, over the last few months I have had the Check Engine light come and go. I had one of my friends at MB check it and run it through STAR. It turned out to be a faulty camshaft sensor, which I changed over the weekend as the light came on again.

Now the issue is that light has not disappeared even after multiple restarts. Normally with the fault sensor it would have turned off again.

I ran it through STAR again this morning and it is giving me the same code as before, should I have done something before changing the sensor. Such as waiting till the light was off or do some sort of reset ?

Thx guys.

-Ben

otto6457

So, you cleared the codes after you replaced the cam sensor and the MIL has come back on?

bsvensson

No I didn't clear it, it never went off. I was expecting it to clear it self after the set amount of circles, so far it has not ?

Plutoe

Just a thought, however after you dial the car in and do the quick test, test the faulty part and confirm the fault, clear the fault, replace the part there should be no CEL.

On the other hand I do not know how many drive cycles it takes to clear an emissions related fault---my guess is that it will not, it will stay on until the ECU is cleared.

That is a potential problem because the longer the CEL is continuously on it warms the plastic bulb holder and I have seen bulb holders fused to the base because the CEL was on for very long time-----that is a PITA to clean and get good contact again.

VividRacing

Clear the CEL/MIL. If it appears again, then the sensor wasn't faulty.

bsvensson

Well I know which sensor is faulty, I have changed it and the light is still on. I even changed it back to the org sensor hoping that the light would turn off and then replace it with the new sensor while the CEL was off. It's like the thing is frozen on now, the code is still the same.

VividRacing

The code may not go away on it's own if you keep swapping the sensors. Your have two options to find out if it's actually a faulty sensor or not. Install the new sensor and either disconnect the battery and wait a few minutes before reconnecting it or go to MB and have them clear the codes.

What was the exact code?

Call your buddy at MB I'm sure he has the codes memorized or it saved under your VIN in their system.

otto6457

This is not how it actually works. You will need to clear the codes via the Star system or even a cheap code reader you can pick up at Auto Zone. You need to get a code free ECU for the system to run through the monitor check again.

There is a commonly held belief that because a code for say, a cam sensor appears in the data stream, the cam sensor is assumed to be faulty. But there can be several things that will cause a particular code to appear that are just as likely as the sensor. High resistance in the harness or connectors is quite common. Poor ground points, and even the ECU itself. Until you clear the codes and do a drive cycle you cannot be sure you have solved the MIL problem.

If you clear the codes and the same code appears then you can be certain that the sensor was not the problem and you can begin to diagnose the circuit with a scope and check your sensor's output waveform at the ECU.

Otherwise you are simply throwing parts at the problem and hoping you get lucky and hit something.

VividRacing

^^^ Pretty much what I was getting at lol

bsvensson

Thx guys!

I had it in to MB Friday. It turned out that it is the balancer shaft which is causing the chain to jump.

Basically what the tech told me is that the year of our E350, it's a known fact that the balancer shaft is made of poor metal and has been corrected in recent years. However not enough incidents recorded to do a recall.

What is happening is that the chain is slowly grinding down the teeth on the balancer shaft wearing them down and the issue over time slowly becomes worse and causes the CEL to go off getting bad readings (camshaft codes for sensor and magnets, STAR recommends to change camshaft sensor and magnets before checking balancer shaft).

I got the car back today and it's a completely different car, more responsive, gears does not jerk up and down through 1-3. Smoother ride in general!

Now since my MB dealer was nice they did this to no cost as goodwill, however the bill would have been in the area of $7,000.00 shown on the statement and it toke them 2 days, just as an FYI to the ones out there with the same issue!!!!

801

May I ask how many miles you have (had) on your 07 e350 when this occurred? and .. for future reference:
http://www.benzworld.org/forums/w221...g-what-my.html

bsvensson

I have now about 86000miles on the car now, when the issue started it had around 50K on there. I drive 62miles a day hwy only, and have not had any issues besides the CEL giving me the P0015 code overretared camshaft sensor bay1, until about a week or so ago the car started driving real bad. It had a rough idle, jerk when accelerating, skip between 1-2-3 gear, make a hard downshift from 2-1 once just accelerated. The car does not have any of these issues now.

They changed the oil and the tech had saved me samples of it, basically it had worn the metal so far down that the teeth was starting to break off and it was obvious in the metal shavings in the oil.

801

Just to clarify, you first got the P0015 code at 50k miles? but car finally became undriveable at around 86k miles? Glad to hear that your Benz dealer fixed this at no charge.

bsvensson

yeah it was recorded back then, all they did was change the magnets and it went away for about 3months. It has always come and gone, after and oil change it would stay off for several months, but then getting close to one it would come on very frequent. So i'm taking a picture of the old balance shaft and posting it here it's in horrible shape!!

VividRacing

What year/model is your car, which sensor did you replace and what was the code for the light that is on?

bsvensson

You might want to go in and have it looked at unless it's a recent swap. It sounds like you are having the same issue as mine! I have been told that any cam related codes could have been a result of my issue.

If you go in and get it cleared see if the code comes back on, if it does then you might want to have it looked closer.