P0012 - Camshaft Position - Timing Over-Retarded (Bank 1)
We focused on the magnets first after researching this thread.
We really are not sure what to do next. He is guessing about replacing the sensors. As far as I know there is 1 crank sensor and 2 or 4 cam sensors.
I sincerely hope it is not a worn gear. My mechanic seems to think it is not, however I am not sure what he is basing that on.
The magnets and sensors are separate components. If fact we had to take one of the sensors out in order to remove one of the magnets due to limited space.
Last edited by Card Shark; Feb 17, 2012 at 02:39 PM.

You have the worn balancer shaft sprocket issue. Engine must come out of the car. I will post DTB.



Thank you for your advice. I will get to work on this and let everyone know how it turns out.
The Best of Mercedes & AMG
Car is a 2007 C230 Sport
When the crankshaft position sensor was replaced: I was leaving a stop light under moderate acceleration and the car seemingly applied the brakes..hard. It was like I took my foot of the gas and brake checked the car behind me, which had to slam on his brakes to keep from rear ending me. Then the car "let go" of the brakes and I could accelerate, but VERY slowly. It was running terrible and I could barely gain any speed to get to the next parking lot to pull over. The traction control "!" light flashed and the CEL came on, then the message center displayed something like "ESP inop. Check owner's manual". I'm pretty sure more lights came on because my dash lit up like a christmas tree, but I couldn't catch them all since I was driving and they flashed on, then off quickly. Mercedes walked me through an ECU reset procedure and the car ran fine, but they still towed it in for service under CPO. I don't know if it matters, but I had a flat that day and was running the spare when this happened. They thought that was the problem at first, which sounded odd to me, but eventually found the fault code for the crank shaft position sensor and replaced it. After that, the p0012 code popped up.
The p0012: I believe 2 camshaft position sensors were replaced during the previous owner's time with the car. I had one replaced shortly after buying the car when a CEL came on and I took it in to have them check it out. I'm not sure what code came up that time, they just said it was for the camshaft position sensor. When I started getting worried was when the CEL came on about a week or so after the crank shaft position sensor was replaced. I checked the code and found the p0012. We cleared it and everything seemed fine for a month or so, and then it came back again, with extreme anger. I went out on a cold morning to start my car and it idled incredibly rough, and low on rpms. The red battery light was going on and off and the CEL came on. It was POURING thick white smoke from the exhaust and I just though, "GREAT, a head gasket". I turned the car off, then attempted to restart it...after turning over for about 10 seconds, the same thing happened. I turned the car off, let it sit for a minute, turned the key to the "on" position, let it sit for 20 sec, then begged the car to run and turned the key. It turned over for 10 seconds or so then acted the same, battery light, CEL, incredibly rough idle, and low rpms. I feathered the throttle for about 15 seconds and it suddenly sprung to life and it seemed like nothing was wrong. The white smoke went away, which put my mind to ease about a head gasket, and the car ran great; the CEL even went away after driving a short while. I drove easy for a while then gave it some 3/4 throttle runs and everything seemed fine. I got to O'Reilly's and scanned the car and found p0012. Once I got to the dealer, they investigated and said it was a magnet and replaced it. I've driven the car for 3 or 4 days since then and its been fine.
Any thoughts on the craziness that has gone on?
Last edited by Steve27; Feb 21, 2012 at 10:39 PM. Reason: text edit
My car hasn't had any CELs since it came back from the shop. It seems to be getting better MPG too, which I read a few other people noticed as well. AVG'd just under 28 MPG fluctuating between 65-80 MPH on the hwy today. I'm still curious if anyone has heard of a C230 acting the way mine did those couple of times and if there could be a larger problem waiting for me once my CPO warranty is over in a few months.

Just make sure the car is not using any brake fluid. A damaged booster can cause smoke. Brake fluid getting into the vaccum line.
Is there any chance you had just filled the gas tank? Overfilling can flood the EECS system & dump raw gas into the inlet manifold via the purge system.
Thanks for your help. Hopefully that was the last of my cars issues, but I will buy all four magnets if I throw another cam sensor code out of warranty and I will replace all of them at the same time. Thanks, again!

Randy
But if it is in the VMI then any dealer can pull that.



With my limited wrenching skills I didn't find it that easy. There is a bracket in front of the intake magnet that I tried to avoid removing because I didn't have the right extensions. I tired the 1/4" wrench trick mentioned mentioned in this thread, and ended up partially stripping one of the bolts. After that I decided to remove 2 of the 3 bolts and bend the bracket back to allow the socket wrench to get in there, which worked. The car does idle noticably smoother with just the passenger side magnets replaced.
Tomorrow I'm going to get a longer better quality 1/4" wrench, and attempt the driver's side.
After loosening the magnets I kept hearing this high pitched elctronic whirring sound in my engine compartment. Does anybody have any idea what that is? Should the battery disconnected?
.I have tried all four magnets with no results,after buying a cheap code reader and finding both codes everything started making sence with the slight vibration and the metal colour in the oil.However being a licenced tech I feel very capible of replacing the balance shaft but was confuzed on why the engine needed to be removed.I knew I would need a few tools to this job properly and when I owned my repair shop (retired now) I had alldata software for the guys to use and thought that would do me good here also (25 bucks for a year) as they give a step by step removal and installation procedure and even pictures
.I'm not trying to promote alldata just saying this is a good tool.After reading through the procedure and there it was my answer,mercedes has installed a counter weight on the end of the balance shaft (rear)which needs to be removed before the shaft can be pulled out the front of the engine.(engine and trans need to be seperated)They also show a tool which removes a link from the timing chain,valve covers need to be torqued down before tensioner is installed in timing chain slider, etc.I'm still going to do this job and was in our local MB dealer finding out prices for the parts needed only to find out MB has a kit for this job
I was told to talk to the service manager.I am going in for them to do thier own diginostic report next week and with all the oil changes recorded (I got them all together fineily)so I have a chance at least for some help on this repair.I have just over 100,000 kms (60,000mi) so I won't hold my breath,wish me luck
Randy



