Hi, Looking for some advise! I have a 2009 C300 (w204) with 66,000 miles that was always garage kept and very rarely saw rain or snow. Problems started a day after i had front of car jacked up looking over my front suspension. Car ran fine and i glanced down and saw the check engine light appear. Checked the obd 2 codes and it mentioned one of the 02 sensors. I brought the car home and attempted to drive on the ramps to look at the sensor location and the car flipped out with my esp warning light coming on and the idle surged. Tried to drive to shop but car went into some type of limp mode so i had it taken by a flatbed. Had a diagnostic done at a shop and had numerous ecu faults. The shop i brought it to wasnt up to the task so i went back 2 days later to retrieve car and much to my surprise got in and drove home like nothing ever happened. After toying and research and a purchase of the icarsoft MB2 scanner i now have the following faults in the ecu with the Check engine light on. P2176,P2237,P0030,P0050,P2240,P0607 and a 1337 Alternator Serial Interface issue. Those were in the MB ecu. The OBD2 codes are P0607 with P2237 and P2240 pending. New to the forum so i hope this post wasnt too long winded. Any help would be great!

 

Can you expend the translation of your 7 codes ?
Your ECU sure has a lot to say...

 

Hi, So here is the long version of the codes. First numbers are from the MB side of the Icarsoft and in parenthesis is the Generic obd code numbers.
0217 (P2176) M16/6 Throttle valve stuck or stiff
1337 (Alternator serial interface can problem
0565 (P2237) Right 02 sensor before cat voltage too high
0443 (P0030) Right 02 sensor before cat heater circuit open
0447 (P0050) Left 02 sensor before cat heater circuit open
0569 (P2240) Left 02 sensor before cat voltage too high
0435 (P0607) Electronic analysis for 02 sensor in ecu defective
Strange deal because the car starts all the time and drives just seems like the idle is a touch low and smells a little rich with the check engine light on, Not sure what is going on! Thanks for any replies!

 

The collection of ECU faults you got delt mean that your ECU is randomly acting crazy, for some odd conditions...
This is a pretty short straw!

I really do not think your throttle body, Lambda circuits are bad per say. Something is causing your ECU to see them that way.

#1 suspect here is the "OIL IN HARNESS"

#2 marginal POWER supply (Alt/Batt; GND/Vcc)

#3 wasted ECU (F-SAM, CAN-C),

#4 HARNESS wiring damages


It may not be easy to find but will be obvious once you get it. ✌️

 

Hi, Thanks for great info and the quick replies! I will need to explore more with the visual inspection before i condemn some pricey components. I hear that the electrical connector on the trans can cause issues if the o rings start to leak any word on that? Also would like to inspect ecu connections at the ecu but am hesitant to pull connectors without disconnecting battery which opens up the discussion of disconnecting battery and causing "SAM" module failure on the reconnect. Any insight would be appreciated! Thanks Again!

 

These are excellent questions. You are very wise in beeing careful not to further upset the electricals of your sick car.

At this stage leave the tranny connector alone for now. Nothing is pointing towards it.

Disconnecting battery is actually a great thing to reboot the SAM modules that are soft-crashed because always powered On. If the F-SAM has been swamped, no amount of reboot will fix defective hard failure.
Anytime you want to disconnect a module, your best bet to prevent errors is to first power down the car.
So definitely disconnect battery before looking at ECU harness.

 

Hi, As always thanks for the info, I would like to post some screenshots of my data from the icarsoft mb2. It has a test at idle function that shows some parameters. Maybe some of the numbers will jump out to someone. I am just getting my feet wet with auto diagnostics so i dont understand all of the data. When i do another scan i will post. Maybe my saga can help the next person. Also was curious about the ECU "Engine" side connector. Can this be disconnected with battery still connected without consequence? I am still concerned that disconnecting battery will send me in a electronics death spiral! LOL

 

I would not.
The one thing you want to avoid at all cost is triggering your car security.
They have a real sofisticated handshake for module validation.

 

Hi, Here are some pics of the data collected from the test at idle function of the icarsoft mb2 reader. The car was running and warm. Maybe some numbers here will indicate an issue. Will try to attach these pics. Thanks Again!

 

nothing's screaming.
Voltage is good!
....

 

Hi, So still poking around with my fault issues and still researching potential problems and am curious about the mention of oil in harness from CaliBenzDriver. I am confused by reading other posts about how the oil is entering harness. Is it thru the internal of the sensor connectors to the extent that it wouldnt be externally visible? or is it clearly visible dripping and running down the outside of the harness? Some posts have the oil showing up at the ecu connector. Like having termites inside the walls! Yikes. Any info greatly appreciated as always! Thanks

 

yes, engine oil comes out through sensors pins and travel to the ECU by capillarity.

Check for signs of "wetness"... at ECU and timing connectors.

Hopefully you don't have this nightmare because it hell of expensive to replace harness and ECU.🤞

 

Hi, Looked at some of the connectors and saw some oil starting in some. I am the second owner and i purchased the car with 24,000 miles on it and from what i am seeing the previous owner may have had the dealer or an indie install a preventative fix in a service bulletin to "save the harness from oil running it" If i am correct the fix is to install 4 short extensions in line with 4 of the sensors. Still not finding any aha moments but only have time on the weekends to mess with it. At this point i have obd codes with reduced power and a check engine light blinking. Codes are for misfires in cylinders 4/5/6 on one bank and worsening emission values. Vacum leak? Shot the cannon and put a maf sensor on it and hasnt changed anything. Weekend is coming so i might try to smoke test the intake manifold. I will keep posting my wins or losses to help others. Thanks

 

Update! In case anyone is interested the document for the wiring retrofit is titled "Campaign-Retrofit camshaft adj. solenoid adapter wire harness. Campaign No. 2012070002, Nov 2012. Model years 2005-2011

 

Do you still have O2/Lambda codes? They could directly be causing your lean misfire.
Try swapping L<->R or replacing with OEM grade.

 

Hi, That is what is confusing me. In all my sessions of tinkering and clearing codes to see what comes back the throttle body sticking or jamming and the o2 sensor codes havent resurfaced. From all my reading and video watching it seams it could circle back to the o2 sensors or a vacuum leak. Still not jumping to any conclusions yet. Anyone ever disconnect upstream sensor and run engine to bypass the sensor? Dont want to fry anything. Thanks!

 

Hi, Also wanted to ask if anyone knows what intake manifold pressure should be at idle? Mine was 540mbar. Thanks

 

Hi, Just wanted to post an update to my problem. Turned out i had one or more bad 02 sensors which cascaded into misfires and many fault codes. Thanks to this forum and CaliBenzDriver i learned a lot about my car and what might be future issues to look for. I am still a newbie to the forum but i can suggest not to be fooled by some of the codes thrown by the ecu. Thanks to all!

 

I don't want to be the sour one to tell you this, but if the symptoms return with the same codes..... You will need a new engine control module. It's a internal power supply issue that can be intermittent. I have done hundreds of ME9.7 modules for these codes.

 

Hi, I am hoping for the best! Not sure what the brain surgeons at MB where thinking and i am no expert but to me electronic devices dont like heat or water! So that being said where do you think MB puts the electronic brain of the car? Naturally it should go on top of the baking hot engine that could possibly get wet. Oh well i guess it looks cool under there. I will keep an eye on it along with the oil in the harness, The sam module failures, water leaks into the can bus connectors, the water in the fusebox, The intake manifold failures, the clogged sunroof drains and so on. At least they didnt put the water pump inside the engine like one of the other manufacturers! Thanks for the info!