CLK500 TWINS

I have posted several threads about this car, my last post received not a single response. I've taken it to the dealer and even they couldn't provide an actual diagnostic. They want me to bring it back and leave it for further diagnostic.

Its an 01 S55 Amg. I bought it a few months ago with a CEL light and a pretty obnoxious vibration in reverse. About a week later before I could even tackle the obvious issues due to the holiday, I had a no charge/flat battery problem. Replaced the alternator and chased down a significant battery draw from aftermarket tv/dvd installation(previois owner). That was fixed.
CEL code indicated that the car was running too rich at idle. Cleaned maf and saw immediate improvement until the following drive cycle. CEL was back and car was running rough, idling high and vibrating in any gear besides park or neutral. Replaced maf with new bosch unit. Same situation-immediate improvement until the next time I started it up. This time however, it ran terrible for a few cycles and seemed to platue where it was no longer idling rough and the vibration was barely there/less obnoxious in reverse. Intermittently I'd feel it return, but nothing like it was before the new maf.
Generic code scan at auto parts store- P0100 MAF Circuit A. Cleaned connection, inspected wiring at maf, cleared code. Car went through same cycle of running great-terrible-platueing. My tech read code with slightly more advanced tool- P2004 Hot Film Sensor. My tech is a family friend who runs a body shop, he does brilliant work but hasn't had alot of time to donate to troubleshooting this. Lifted carpet in passenger footwell looking for infamous k40 fuse, found additional wiring for dvd system- ac adapter, "amp" fuse and a converter box that was generating alot of heat. He removed them and capped those wires.
Car ran the same but upon a second drive cycle (cold start) I had an rpm surge to about 1500 and stayed there then down to 1000. While waiting for him to have another opening in his schedule, It did it's same run terrible-platue cycle. This time however, I started noticing intermittent surges upon breaking. Rmps will gradually drop and once they get to about 900 they will shoot back up too 1000 before continuing to drop and you feel the jolt. At one point since this started, after placing the car in park it reved to 1500 and stayed there until I put it back into drive, then it lowered to about 700. Put it back in park and it was fine.
Since then, cold starts seem to take more effort and upon starting it hits 1500 and then I can watch the rmp needle hunting at 900-1000. Before it comes to temp, idle feels clunky and vibration is apparent.
Took it to Mercedes the other day out of sheer frustration and the only thing they could tell me was that I needed engine and tr anny - suspected the tranny mount due to vibration. Regarding the CEL/MAF and idle surging- all they could tell me was that the voltage to the MAF was too high even with the car off. Im a female, I dont do my own work but I do troubleshoot to help my guy along given the fact hes got a business to run too. Mercedes can't even pin this down without me leaving it for them to tinker with and Im lost in all the information I've read. My vin is as follows: WDBNG73J61A168010. ANY HELP IS MUCH APPRECIATED.

amstel78

That sounds awful. I'm surprised MB couldn't help you. Perhaps you should take it to another MB dealer, or an independent who specializes in our cars. I can't help you further other than to provide the following link which gives a bit more information regarding the P2004 code your mechanic provided. Maybe reading through it might give you a bit more insight into diagnosing the problem. Good luck.

https://www.yourmechanic.com/article...-jamahl-walker

CLK500 TWINS

Amstel78, thanks. Yea, I knew it was bad when the SA told me I needed mounts, but they won't be charging me for the diagnostic because they can't figure it out.

tusabes

Am I correct that it will run fine the first time the MAF is installed , but upon the second start the problem resurfaces ?

i may have a workaround for this - try a battery brain t3 from Amazon

its a a battery disconnect with a remote keyfob . Everytime you leave the car click the remote and the car should reset . Click the remote when you get back in .

you might lose some stored radio settings etc , but if it fixes your drivability problem it's worth it . It's super easy to install right on top of the battery . I put them in all my cars with weird electrical problems and while it doesn't fix the root cause it does solve the problem at a low cost

CLK500 TWINS

Tusabes,

Yes, the car runs pretty much perfect, even with less vibration (I'm waiting on the mounts to come in). Any time the code is cleared, the symptoms do as well. Second drive cycle following this, code comes back and symptoms return at their worst for two or three cycles- then they level out with intermittent bs.

I will look into this, I dont use the radio much anyway. My only question is, would this keep the CEL off long enough for it to pass inspection? Im up at the end of this month and still scratching my head. My guy is taking it in next week to try and tackle it, as well as replace the mounts and do a few minor cosmetic things for me. If this could work to keep the CEL off and the car running well though, I'd be happy enough.

tusabes

Depends if they turn the car on and off for the inspection , and whether they look for the "monitors "
to be ready .

There are several emissions sensors /monitors that are reset when you clear codes/disconnect battery . (That also seems to be what helps fix your problems )

the monitors do not all come online and become ready until after several drive cycles , so if your emission test checks the readiness of monitors it will fail

I am in California and they do check monitors

CLK500 TWINS

Gotcha, I am in Ny and they do here as well.

wallyp

That appears to be a required part of the inspection per Federal rules...

CLK500 TWINS

So, Mercedes wanted me to bring it back in for further diagnosis, but I haven't haf the best experiences with this particular dealership (telling me esp modules were vin coded and had to be done by the dealer when I jad my two CLK500's). So I decided to take it to one a little further to see if their was a difference in the competence.

Epic fail, as the shop manager came back to talk to me and ask me how far I wantes to go with this. He proceeded to tell me about how my suspension had been converted and the entire abc system guted. (As if I didn't know this, it's a large part of the reason I bought it, having converted my CL600 and had many conversations on here about gutting the system. The suspension had no bearing on why I was there and I advised the SA that it was converted). He continued to tell me that I had plugs coming off my engine that aren't connected to anything and they cant seem to figure out where they plug up to ( this confuses me to, see pictures below, I've posted them before but no one replied. I think its possible previous owner added a supercharger and subsequently removed it, but I have no idea. Any help here would be great).
Armed with all my absorbed knowledge, I ask him about the codes that the sds is pulling. He proceeds to tell me that he can't get the system to communicate with the ME, it keeps giving him an exclamation point indicating that the brain to the engine and tranny are pretty much offline. This doesn't seem plausible as the car starts and drives and is really running quite well (running techron through the system currently and it may be coincidental, but shes been running nicely since minus some minor vibartion from the collapsed mounts). The other Mercedes had it last week and were able to connect it and atleast tell me the voltage to the maf was too high. Auto parts store ran P0100 maf circuit a code and my tech ran p2004 hot film sensor code before that.

They wanted me to leave it for 4 hour diagnostic with only 2 hours to be apploed to whatever repair. It smelt like bs to me, which is what I told the SA. They didn't charge me and he gave me the number of an indie who specializes in Mercedes. He was nice, said I needed an old timer because these young guys don't know how to do anything if the computer doesn't tell them to.

Immediately took it to auto parts store and had it scanned. Same P0100 maf circuit a and he had no problem getting it to connect.
I bought what was supposed to be a new Bosch from amazon for $107, fulfilled by Auto Parts Now
https://www.amazon.com/gp/aw/d/B001CO2GE6/ref=ya_aw_od_pi?ie=UTF8&psc=1#nav-search-keywords. Is it possible that I just got a knock off or a defective one? My guy doesnt think so because of how much better the car is running. I didn't have an maf code prior to changinv the maf though. I was running too rich at idle. Maf fixed that but is throwing its own code. Is it possible for it to be kind of working, but not as it should? Suck it up and try another? I can't get it into my guy or the benz electrical specialist till mid next week anyway. Is it worth it to try new maf just to see if its that simple?

Right hand side. Unattached plug wrapped in orange rubber band

Left hand side, same plug type with orange banding
Exposed wiring running alongside alternator??? Shouldnt it be covered? Black zip tie that's literally desintigrating.
Exposed wiring runs up to this cluster that is tucked under plastic cover in the very front of engine
Same wire cluster under plastic strip behind secondary air pump
​​​​​​​

CLK500 TWINS

Sorry for any typos. Did this on my phone and it sucks.

tusabes

I doubt another maf will help but yes you often get Chinese knockoff when buying from third party Amazon sellers

Try that battery disconnect workaround first

CLK500 TWINS

I actually took a look for this at my local advanced auto and the guy behind the counter didn't seem to have any idea what t was. I'll have to order it off Amazon. Are there different brands on this or only the one though? I read some of the reviews and people said they need to be replaced rather often.

Any idea about the plugs and that exposed cluster of wiring running up by the alternator?

CLK500 TWINS

I know you are pretty well versed in the wiring of these cars

tusabes

That's the right one . I haven't seen anyone besides Amazon sell it

All the battery disconnects sold in local stores require you to open the trunk to disconnect , they don't have a remote control . I have them in two cars and no problems , but like all produced in China products, there are sometimes duds


As for all the disconnected wires in your car , it likely had been worked on by bad mechanics in the past who did not repair things properly , and likely will never be right , so a "workaround " is your best shot at getting it to run

Icarus747

I def. would try another MAF sensor. Bad parts are made all the time. I chased a crank sensor round and round on my wifes Nissan. Third one worked. Then was getting cylinder misfire codes after fixing the crank sensor. Lo and behold it was 2 bad coils. Nissan EVEN had a recall for the crank sensor..but wouldn't honor it. Of course, this all happened right after she made her last payment.

CLK500 TWINS

Tusabes,
I hear you and I hate to be that person who isn't listening but keeps asking questions. I appreciate the work around tip, but in all honesty, the only reason this one is driving me nuts- other than genuine curiosity and a propensity for puzzles and problem solving; I need the car to pass inspection. It's my understanding that the work around isn't going to solve this, as much as it may cure my desire to see the cel light stay off.

I did get a new Bosch MAF today, came packaged correctly (stay away from Amazon's market place sellers). Also bought new air filters to be safe. All looked great, rest the code. Started her up and it had no codes, no cel. Then it got weird, it was idling rough, my guy revved it in park to about 2k rpm's and took his foot off - rpm's kept climbing to around 3k. If he tapped the accelerator again, it would drop from 3-2k, if he put it in gear it would drop to a normal 500-700 range. He started it up a few times, we tried the idle relearn procedure and the eco reset procedure- still did it.

Car drove fine, idled fine in gear, idled kind of rough when in park. Temperature was at normal operating temp. All the while, star up cycle after cycle- cel light stayed off and car threw no codes. He drove it and as I couldn't leave it today, I left. Car did surge while braking (drop to 900-surge to 1000- then back down during rolling stop) as it had already been doing occasionally.

Thinking I had uncovered a brand new issue and 6-7 drive cycles later, Im sorry to report the cel is back on and the car is no longer surging. Have to have the code read tomorrow.

CLK500 TWINS

It may be worth mentioning too. The other night, I heard this buzzing when I turned the car off and isolated it to the little fan by the sos. Hadn't heard it prior and haven't heard it since. Today, while enjoying the no cel and contemplating my weird rmp issue - I heard this terrible droning noise. Turned everything off and isolated it to my instrument cluster. As soon as the lights (stay on for a minute after car is off) went out, so did the noise. Apparently these are fans that sample cabin air-the polution sensor. With the new CEL or return thereof, I didnt hear it anymore. Is this now down bad wiring or is my ecu going or possibly corrupt (performance chips-bad flash-corrupt files? Possible?). Its like driving a computer with a virus and I keep getting pop ups of random ****.

tusabes

You should not delay getting the disconnect - you need to confirm whether it will workaround your issues , and you can simply not utilize the disconnect button to get enough drive cycles to pass inspection . Just installing it will not cause you to fail insoection , simply do not use the remote disconnect when accumulating drive cycles so the monitors are ready

you should buy a $20 code reader that checks monitor s so you can check the monitors yourself and run to the inspection place as soon as the monitor are ready and before the cel light goes on

quickly get it inspected during the time you can get it running correctly .

CLK500 TWINS

At this point, I have nothing to loose. I was actually about to purchase the mbii by icarsoft, figuring it may prove extremely useful. Any recomendations on a cheaper one.

amstel78

What tusabes suggests is a suitable workaround, but that's all it'll be. Just a band aid to cover up a much larger problem. The fact that there are connectors and wiring harnesses left unplugged is seriously suspect. You need to speak to a good indy that has extensive experience working with MB electrical systems and wiring. As I suggested on the other site, I would talk to Victor and make an appointment at your earliest convenience. He should at the very least, be able to tell you what those plugs are for that aren't connected to anything, and hopefully be able to pinpoint the multitude of issues you're experiencing.

From what you've described, I don't think this can be narrowed down to just one faulty component such as the MAF. The ECU is probably going bonkers due to other systems not functioning or not responding to queries sent by the computer. In turn, the car just doesn't know what to do with itself.

P.S. Any decent $100-150 OBDII scanner can read codes, check monitor readiness, and clear DTCs if needed. I use one made by Innova. They have several different models ranging in price. Check Amazon.

CLK500 TWINS

Fearing the worst, I have begun to suspect my ecu as being in need of replacement or repair. I'm not certain, but the additional plugs have me thinking there may have been some performance mods made to the car and subsequently removed. According to a top rated European repair and pro tuning shop out here on the Island- "dumb boys ruin factory ecu's all the time because they want the performance upgrades without paying the pro tuning price."

My guy is way too busy and although I know he will put the time into getting it fixed, at the sweetheart price, it'll be in between his regular business and he'll have it for a while because of this. I really wanted to call Victor as I'm confident that if anyone can do this, he can; I still may. He is in City Island, BX though and I'm on the Eastern end of Suffolk County, Long Island. It's a considerable distance for dropping it off and leaving it and then having to get back out there to pick it up.

The Euro repair & pro tuning shop has rave reviews and they gave me a nice price on mount installation. Less than $600 compared to Mercedes $1000 labor cost. They are going to try and diagnose it while they have it, maybe getting the engine off the frame will help (wishful thinking- ending crimping a wire or hose from collapsed mounts. ). If they can't pin down what kind of mod wiring work may have been done, then I will have to take it to Victor and figure out how I'll get home.

I will keep you gentleman updated

amstel78

I'm just saying because those plugs that aren't connected (one with orange band for instance) looks factory, and appears to be going into a factory wiring harness. That leads me to believe that it was at one point hooked up to a sensor that's no longer present.

Does the car appear to have all of the factory intake plumbing intact? Also, is there a MAP sensor in your car?

Read this, especially the last paragraph: http://fixcars.net/map-sensor-symptoms

CLK500 TWINS

I agree that these plugs do look like they belong to the car, there just isn't anything to connect them to. I simply couldn't deduce an educated guess other then they may have been added on. I was told (over the phone by a tech I called a couple of weeks ago) that Mercedes' harnesses sometimes do have additional plugs, as Mercedes had far less variations in their wire harnesses as they did their engines. How true this may be, your guess is as good as mine. The second Mercedes dealer I brought it to mentioned these plugs and not being able to figure out where they connect to. He also said that my car's EM wouldn't communicate with the Star, so I question his competence, as I had it scanned again at an auto parts store immediately upon leaving the dealer.

I am glad you mentioned the MAP sensor, as I have come across this in all my searching. Mercedes parts diagram has it labeled as- a mass air sensor and this made me very curious as to whether the code was for the mass air flow sensor we were actually paying attention to. Their parts diagram (pulled according to my vin) also tells me that it does not fit my vehicle. This is what made me abandon this as a possibility, although the characteristics are spot on. Unless the diagram I am looking at is simply wrong and my car does in fact take this part- which is missing.

I may need to look further into this, as even if my car was post-map sensor or just simply made without one, there has to be another sensor that is being used in its place. Atleast one would think.

CLK500 TWINS

oh and to my untrained eye, yes the intake system seems to be complete.
https://www.oemercedesbenzparts.com/...Y4LWdhcw%3D%3D

This is the parts diagram I have been following. What's curious is that I just put the part number into FCPEURO's website and they say it fits my car.

amstel78

Yes, that's the one. Your car should have one if I'm not mistaken and could be the source of your problem.

https://www.fcpeuro.com/products/mer...sor-0261230189

BTW, if you're able to locate your map sensor, try unplugging it. If the idle stops surging, then the map sensor has gone bad and needs replacement.

Another resource to read: http://www.gonzostoolbox.com/Knowled...-Failures.html