P0012 - Camshaft Position - Timing Over-Retarded (Bank 1)

Make sure that air cleaner is on properly. Had a W204 the other day with the same issue.
Buy a $50 scanner from Harbor Freight.


Thanks for the help!

Pleased you have found the problem
it would die. Let it sit a while and it would restart. This last time it Quit
at a sign and restarted 30 min later took off made it 5 miles and just like
someone tuuned the key at 60. Just cranks and no fire. waited 30 min
agaim started and made another 5 miles and dies. i went and got my trailer
and when I went to load it it started again. It's home now and will start
when it's been sitting.
CEL code is P0300 which is misfire.
Is this a CPS or fuiel pump issue.
New with the Benz and trying to learn and appreciate any help.
Nic

Nevertheless check that the front fuel rail has >3.8 bar pressure at the Schrader valve while cranking.
Good luck!
Though my car is run 80-90% highway.
The Best of Mercedes & AMG
underneath at the rear of the engine. I will be testing the bar pressure first.
but it seems to be a hear related issue. Starts when cold and stops after running a while.
Nic
parts to remove (MAF and Lower duct) so I take the right parts.

You are not kidding. I climbed up on the engine and tried to see it and
could only feel it. What is holding it on? Bolt what size, Torq size, allen head size.
I take it that a Bosch replacement part is recommended or is something else better.
Thanks Nic

https://mbworld.org/forums/clk-class...ft-repair.html
If you get DTC codes 1200/1208 (P0017/P0016) together it is likely the worn sprocket issue.
Excellent explanation by MBtech1098 with pics.
quote
"When DTC's 1200 and 1208 are present together, there is a high likelihood that you have a balance shaft/idler sprocket issue. These faults will usually not appear separately unless there is a problem with the adjuster itself. To understand why you need to know how the cams are connected. The chain is connected to both left and right intake cam adjuster, and via gear train to the exhaust adjusters. (See figure A.) If base timing is off on the intake, then base timing is off on the exhaust as well.
Figure A

These faults will appear after the ME attempts to adjust the cams, however the value deviates by more than 9 degrees crank angle of specified.
1200 - Constant adjustment of exhaust camshaft of right cylinder bank in direction 'Retarded'(P0017)
1208 - Constant adjustment of intake camshaft of right cylinder bank in direction 'Retarded'(P0016)
Usually when you have an issue with the cam magnet/solenoid, you will have one of the following DTC's: 0059, 0060, 0063, 0064, 0271, 0272, 0275, 0276.
With the use of an oscilloscope it is very easy to determine if the engine is out of time. (see figure B) By connecting a multi-channel scope to all the cam position sensors and crank position sensor we can get a graphical representation of engine timing. We are also able to determine how many degrees out of time the engine actually is. A & B are the intakes and C & D are the exhaust. E is the crank position sensor. If you notice the two black lines they show an engine in time. If the engine was out of time one of the banks would not be inline. You can then count the segments in row E to determine the amount of degrees of deviation. The flywheel has a total of 60 segments minus 2 to identify cylinder 1, this means that each sine wave of the crank sensor is equal to about 6 degrees.
Figure B

As far as goodwill, if you have low milage on your vehicle, there is a good chance you could get it covered. But if you have been doing some driving it is more likely that it will not be covered. Goodwill has many variables however."
unquote
Last edited by Glyn M Ruck; Jan 1, 2012 at 06:44 AM.
I have made several attempts (using 1/4 wrench) to take out the bolts right behind the PS reservoir w/o much success. I feel that PS reservoir need to be removed to order to get enough clearance - see the attached picture. If so, could you please point me to some diagrams as how the reservoir's attached to the engine body ? I can see the 2 long bolts, but others may be hidden and I just want to make sure that I have a well thought out game plan. 2nd question is is it safe to assume that my car won't experience fault code scenario 1 (1200 & 1208 ck light) since my engine serial # is 273xxx143814 which supersedes 273xxx088611 ?
Much appreciated for your help
Oh, one more question, I purchased eqqus 3100 scanner from walmart and cleared the p0012 code. two of montoring icons (O, oxy sensor & C, CAT) keep on flashing - not ready ?? I don't suppose that this is related to p0012 issue, but has anyone else experienced this issue / is it normal perhaps ? hope I can pass the smog
Last edited by last993; Jan 29, 2012 at 02:22 PM. Reason: more info
Question 1, does the cel have to be reset in order for ecu to manage all input and run the engine properly? (could it be still in "limp" mode) Having saw the picture of the worn out balance shaft gear on this thread,
Question 2 could this be the vibration problem and I still will have to change chain, gears and balance shaft? Talking to dealer he said engine has to be removed for this job
Question 3 is this because the oil pan has to be removed to change oil pump or is there something I'm not seeing with balance shaft replacement?
Question 4 is there a more resonable priced timing chain "kit" availible? Thanks for any help in advance
Randy

Question 1, does the cel have to be reset in order for ecu to manage all input and run the engine properly? (could it be still in "limp" mode) Having saw the picture of the worn out balance shaft gear on this thread,
No - the engine will run normally once magnets are replaced - it is not in limp.
Question 2 could this be the vibration problem and I still will have to change chain, gears and balance shaft? Talking to dealer he said engine has to be removed for this job
You only have a balancer shaft issue if you get a P0016 & P0017 together. The engine does have to come out.
Question 3 is this because the oil pan has to be removed to change oil pump or is there something I'm not seeing with balance shaft replacement?
You can't get the balancer shaft out easily without removing the engine & you have the oil pump issue
Question 4 is there a more resonable priced timing chain "kit" availible?
No - please use OE parts & the new machined from steel sprockets instead of sintered ones. You don't want to have to do this again
Thanks for any help in advance
Randy

I have made several attempts (using 1/4 wrench) to take out the bolts right behind the PS reservoir w/o much success. I feel that PS reservoir need to be removed to order to get enough clearance - see the attached picture. If so, could you please point me to some diagrams as how the reservoir's attached to the engine body ? I can see the 2 long bolts, but others may be hidden and I just want to make sure that I have a well thought out game plan. 2nd question is is it safe to assume that my car won't experience fault code scenario 1 (1200 & 1208 ck light) since my engine serial # is 273xxx143814 which supersedes 273xxx088611 ?
Much appreciated for your help
Oh, one more question, I purchased eqqus 3100 scanner from walmart and cleared the p0012 code. two of montoring icons (O, oxy sensor & C, CAT) keep on flashing - not ready ?? I don't suppose that this is related to p0012 issue, but has anyone else experienced this issue / is it normal perhaps ? hope I can pass the smog
You will not suffer scenario 1 if your car is out of the fault VIN range.
I can't comment on your O2 flashing lights. Read the Equus Innova manual that came with your scanner.
Thanks again for all your help and the links
Randy
If you can get longer 1/4" box wrench, that will make the job simpler. Harbor Freight has the set for relatively cheap.
So you're saying your mechanic already replaced the "four magnets." Those are the camshaft sensor magnets, right? But you're also saying he thinks it's the cam sensors? I guess what I'm saying is your post is kind of contradictory, as it says you replaced the 4 magnets but then the problem might be the cam sensors again?



