When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Mercedes noob here, but I've been wrenching on cars for most of my life. Back in December I picked up an exceptionally clean 06 C280 4matic with 43k on it. Since then I've put another 10k miles on it with no problems aside from intermittent keyless entry and sat radio, and a couple interior issues (drivers door pull, right rear door lock mechanism, and a broken speaker grill.) today I was driving home from work, and the car stumbled momentarily going into second gear. A block later, it died sitting at a light. Put the car in Park, removed the key, and tried to restart the car. Key turned like normal, but won't turn over at all. Pushed the car into a parking lot and started troubleshooting. Battery sits at 12.5v, fuse 52 is already a 20a and isn't blown. Removed and cleaned the battery terminals and was able to get the starter to bump momentarily but not turn over fully, just a fraction of a second. I assumed the battery was bad, so I removed it and took it to Auto Zone for a replacement. They tested it at 900 CCA and surprisingly it tested as good. Had them charge it for me and reinstalled. Still nothing. Tried to jump start it, same thing. Gave up and called a tow truck. Found out that the factory tow hook adapter was missing from the tool kit, and they couldn't tow it. Going to try the dealership tomorrow for a tow hook so I can at least get it home safely, then I need to figure out what went wrong. Still a bit suspect of the battery, but I'm wondering if I'm missing something here. Any ideas? Really hoping it's not something expensive...
If there's one thing I've learned from this site and the internet in general, it's that there's a write up on how to fix almost anything wrong with this car, BUT if I were in your shoes, if you can't pull an OBDII code, I'd use mercedes or a really strong indy mechanic for their ability to diagnose, then go to the internet.
Went to the dealership today and spent $40 on what amounts to an eye bolt, then had the car towed to a friend's house. Pulled the codes and got the following:
P0100 Mass or Volume Air Flow Circuit Malfunction
P0560 System Voltage Malfunction
P2090 (C) self adaptation R cyl bank for enlean at partial load below limit
P2094 (D) self adaptation L cyl bank for enlean at partial load below limit
I figure the system voltage malfunction code is probably from me screwing around with the battery, but the other three sound like they could be related, possibly a faulty MAF (or clogged air filter) causing the car to run excessively rich. The part that doesn't add up is that the car had been running great and getting good fuel mileage before it died abruptly. Parts guy at the dealership said that the symptoms were textbook for a failed CPS, but that was before I had the codes, and it doesn't seem to fit now. Any ideas before I start throwing parts at it?
After a bunch of googling, I'm seeing the P2090 and P2094 codes listed as camshaft position sensor codes from other sources, not sure who to believe now. Going to try resetting the codes tomorrow, fire it up, and see which ones come back. Anyone have Alldata access?
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Originally Posted by scottonfire
If there's one thing I've learned from this site and the internet in general, it's that there's a write up on how to fix almost anything wrong with this car, BUT if I were in your shoes, if you can't pull an OBDII code, I'd use mercedes or a really strong indy mechanic for their ability to diagnose, then go to the internet.
I think you are quite wrong. Our Wiki is an accurate source of information.
The technical people on MBWorld are better at diagnosis than the average Dealer or Indy with all their advantages of having the car in their possession. Most of them are just parts changers.
The output you get depends on the accuracy of your input & your ability to understand what is being said. We are not clairvoyant.
We have solved many issues here with collective input that stumped the dealers.
You need to learn to sort the wheat from the chaff on the internet.
Last edited by Glyn M Ruck; Jul 30, 2014 at 11:33 AM.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Originally Posted by PSYKO_Inc
Went to the dealership today and spent $40 on what amounts to an eye bolt, then had the car towed to a friend's house. Pulled the codes and got the following:
P0100 Mass or Volume Air Flow Circuit Malfunction
P0560 System Voltage Malfunction
P2090 (C) self adaptation R cyl bank for enlean at partial load below limit
P2094 (D) self adaptation L cyl bank for enlean at partial load below limit
I figure the system voltage malfunction code is probably from me screwing around with the battery, but the other three sound like they could be related, possibly a faulty MAF (or clogged air filter) causing the car to run excessively rich. The part that doesn't add up is that the car had been running great and getting good fuel mileage before it died abruptly. Parts guy at the dealership said that the symptoms were textbook for a failed CPS, but that was before I had the codes, and it doesn't seem to fit now. Any ideas before I start throwing parts at it?
The CPS does not usually prevent crank. It prevents start if failed but usually permits crank. Those first two code explanations are correct. The P2090/94 etc. series are Benz specific codes. Not general OBDII convention. They might be BS without a Star.
Unstable voltage can generate all sorts of spurious codes.
The first thing you need to solve is why the vehicle won't crank.
- Seems your battery passes a load test ~ suspicion no1 ~ Borrow another battery
- Start enable fuses are 31, 52, 57. 52 blown prevents crank. Yours is OK
- Then you need to check the starter Relay in cavity S of the front SAM
- Then check all wiring & earth straps including the connector block on the firewall for burning or bad connection
- Check the starter motor & it's engagement solenoid by making a direct connection from the positive terminal of the battery. You might have a duff starter solenoid or motor.
- I would change the CPS as a matter of course. They get as hot as hell & fail frequently. Only use genuine Benz.
- Make sure the CPS & temperature sensor connections are OK. They are enterrogated before start is enabled.
Let's get the thing cranking & starting first. Then you can worry about other codes & fuel trim. The MAF is out of circuit at cold start. So called "open loop" fully enriched.
Hang ten & I will post the start procedure link so that you understand the process.
Good luck!
Last edited by Glyn M Ruck; Jul 30, 2014 at 11:27 AM.
Thanks Glyn! I also forgot to mention, while I was waiting for the tow truck today, I tried to start it again, and it actually started and ran for 1-2 seconds before shutting off. Tried to start it a second time and again it wouldn't turn over. Since the key turns I'm thinking the EIS is okay, which is a relief since that's a $600 bullet dodged. Gotta be something computer controlled...sort of tempted to try the CPS just because it's the cheapest option (about $40 at the dealer) and would probably fail soon by the sound of it even if it's okay now.
Cleared the codes and re-scanned, and the only persistent code was P0560 - system voltage. Brings me back to my first instinct; the battery or maybe the voltage regulator? Going to pull a battery out of one of my other cars and give it a shot, if not I'll pick up a CPS tomorrow and buy a fuel pressure gauge...
Even with Glyn's help, I don't think there's a substitute for a mechanic standing over your car checking. How much is a diagnostic from MB? For the amount of time you'd spend systematically checking everything, I think you'd get a better return on your time having a professional physically diagnose it. Then you can probably find a youtube video showing you how to fix it.
Last edited by scottonfire; Aug 1, 2014 at 12:37 AM.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
This is only true if you are not a competent DIY'er. Many You tube videos show the wrong way to do things that could lead to trouble. This is particularly true of You tube transmission services.
If you have no technical ability then take the vehicle to a Dealer or competent Indy & be prepared to pay.
This forum is to help those that have acceptable DIY capability & the technical ability to fully understand what they are being told. Also to point out when the Dealer or Indy is BS'ing them. This happens often. One only has to look at the W204 forum & the number of dealers that don't service the 722.9 transmission properly & BS owners about not draining the Torque Converter. Indy's also tend to proliferate all the damn myths in the game like not servicing high mileage transmissions & that some how old screwed fluid holds them together.
If you have no technical ability then take the vehicle to a Dealer or competent Indy & be prepared to pay.
This is quite an overstatement. Of course this forum is helpful or I wouldn't be on it. But it's obvious this guy's problem warrants an actual inspection from a professional, lest he inspects everything, which seems more about latent hostility towards mechanics than this guy's problem. And while youtube videos have flaws, so do a lot of these posts. Most of the time, when I'm launching into a project, I have to read several different posts to get a straight answer, and even then, I'm usually left high and dry when I have a very specific question towards the end.
This is quite an overstatement. Of course this forum is helpful or I wouldn't be on it. But it's obvious this guy's problem warrants an actual inspection from a professional, lest he inspects everything, which seems more about latent hostility towards mechanics than this guy's problem. And while youtube videos have flaws, so do a lot of these posts. Most of the time, when I'm launching into a project, I have to read several different posts to get a straight answer, and even then, I'm usually left high and dry when I have a very specific question towards the end.
Bingo. I have read 75% misinformation on this very forum and youtube videos are a joke mostly. It never ceases to amaze me how much money people spend throwing parts at cars because they read in a forum that it fixed someone else's similar problem. Reading around a forum like this there's a blanket mentality that technicians are bad, and dealerships 'steal' your money. Most techs I know can diagnose 3 cars before the average guy can read forums and self diagnose his own car.
Last edited by Holmes5518; Aug 1, 2014 at 10:22 PM.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Originally Posted by scottonfire
This is quite an overstatement. Of course this forum is helpful or I wouldn't be on it. But it's obvious this guy's problem warrants an actual inspection from a professional, lest he inspects everything, which seems more about latent hostility towards mechanics than this guy's problem. And while youtube videos have flaws, so do a lot of these posts. Most of the time, when I'm launching into a project, I have to read several different posts to get a straight answer, and even then, I'm usually left high and dry when I have a very specific question towards the end.
This is not an overstatement. It is merely a statement of fact. If you don't have the ability then don't mess with it as it could cost you dearly.
This forum has many that enjoy wrenching, know what they are doing & save themselves some money. Hogger is a good example but there are many. Some simply don't have the money to pay somebody else to repair the car. Some just don't want to pay somebody else to repair the car.
Holmes & I agree on You tube.
Having had a global job & lived in many countries including the US I have concluded that diagnosis skills are poor at many shops. Of course there are some excellent ones.
What bugs me is dealers & MBUSA that support them & lie to customers. It's all too common. Of the sections that I look after it is most prevalent on the W204 forum. Classic examples are telling people that the TC on a 722.9 transmission does not have a drain plug & violating the WIS. Another is EIS/ESL failure. They seldom diagnose which is at fault. They simply replace both at the customer's expense & I can go on & on with examples.
As I have said before. The problem with the internet is you have to learn to sort the wheat from the chaff! This can certainly be an issue.
Even if one intends letting a shop handle the vehicle being educated on the subject helps.
Last edited by Glyn M Ruck; Aug 2, 2014 at 06:12 AM.
Wow, my broken car seems to have spurred some serious discussion. Gonna have to agree with Glyn, if you're at least moderately mechanically oriented, the information is out there to fix almost anything. It does seem that Mercedes has made certain things more difficult, presumably to help their dealerships make more money on service, but I've also heard a ton of horror stories about dealership mechanics. Having worked in a shop before, I really don't think there's anything a dealership can do that I cannot; aside from things involving specialty equipment not available on the outside. The only difference is that they have experience while I am learning as I go. Rant over, back to troubleshooting mode.
So today I swapped out the CPS, no change. Discovered the service menu in the cluster and shut off ESP, no change. I can get the starter to bump momentarily, and can hear either the fuel pump or radiator fan spin up for a second, but can't tell which since it stops before I can even make it out of the driver's seat. If I let it sit for a few minutes, I can bump the starter one more time. Gotta be something electronic that's inhibiting the starter. I'm thinking next test will be fuel pressure, but I have to buy a gauge. Any other ideas?
Having worked in a shop before, I really don't think there's anything a dealership can do that I cannot
How about find a diagnosis in under 6 days? I guess you don't need this car to be running anytime soon. Otherwise, how else could you justify climbing a fence when you could just open a door?
Haven't been devoting my full resources to the car since I've got a day job and other commitments. I've got another car I can use in the meantime, so it hasn't been a pressing matter. Money's tight, and I'd rather not spend on diagnostic fees when I can do the same thing myself for free. That's where the experience vs. learning comes in. I can get the same result in the end, it just takes longer.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Originally Posted by PSYKO_Inc
Wow, my broken car seems to have spurred some serious discussion. Gonna have to agree with Glyn, if you're at least moderately mechanically oriented, the information is out there to fix almost anything. It does seem that Mercedes has made certain things more difficult, presumably to help their dealerships make more money on service, but I've also heard a ton of horror stories about dealership mechanics. Having worked in a shop before, I really don't think there's anything a dealership can do that I cannot; aside from things involving specialty equipment not available on the outside. The only difference is that they have experience while I am learning as I go. Rant over, back to troubleshooting mode.
So today I swapped out the CPS, no change. Discovered the service menu in the cluster and shut off ESP, no change. I can get the starter to bump momentarily, and can hear either the fuel pump or radiator fan spin up for a second, but can't tell which since it stops before I can even make it out of the driver's seat. If I let it sit for a few minutes, I can bump the starter one more time. Gotta be something electronic that's inhibiting the starter. I'm thinking next test will be fuel pressure, but I have to buy a gauge. Any other ideas?
You are going to have to go through the check list I gave you. Fuel pressure won't inhibit cranking.
BTW Whenever you start the fuel pump runs for a few seconds to bring the rail up to pressure & then stops. Then you can crank & achieve start.
Ok so here's where I'm at: didn't have the chance to do anything with the car for the last couple days, but did some troubleshooting tonight. Swapped battery for a known good battery out of my other car, no change. Verified the 3 fuses were good. Replaced starter relay, no change. Checked all power cable and ground strap connections, everything looked clean. Reseated ECU connectors. Replaced CPS. Verified CPS connector was good. Still need to test the starter motor, didn't bring any wire with me tonight. Starter motor wouldn't explain why it died though. Where is the coolant temp sensor on this engine? I'm running out of things to test here. I did notice that when it died it was 90+ degrees outside and the starter wouldn't turn at all, but when I've been troubleshooting it's been at night with cooler temps and I've gotten the starter to turn intermittently, makes me wonder if it's temp related. I can usually get the starter to turn for a little over a second before it stops, but then it won't respond unless I let it sit for a half hour or so. Really don't want to take it to the dealer, but I'm running out of options here...
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Rear of engine ~ item 30.
We have a rash of starting issues at present.
We are closing in on:
- EIS
- Starter motor or it's engagement solenoid
- Interlock. Waggle the shifter around in Park or Neutral. I'm starting to wonder if gummy shifter switches might not be an issue in cars that don't display the usual culprits.
Last edited by Glyn M Ruck; Aug 7, 2014 at 09:23 AM.
Money's tight, and I'd rather not spend on diagnostic fees when I can do the same thing myself for free. That's where the experience vs. learning comes in. I can get the same result in the end, it just takes longer.
You spend more money in swapping and plugging in parts. You are flying blind here. You aren't actually diagnosing anything.
How about voltage measurement to the starter while turning the key? How about source voltage reading while key is turned? Voltage drop between battery posts and terminals? You need to start getting some solid data, not just playing parts darts.
Bridged starter relay terminals with a piece of wire and the car turned over just fine, still didn't start with the key on. Definitely something computer controlled at this point. I'm still open to any suggestions but I'm wondering if there's much more that I can troubleshoot without a Star machine...
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
No one is denying that the dealer has an advantage over DIY or Indy in that they also try parts from spares dept if the Star does not give them the answer. The Star frequently does not give the answer & todays Techs are generally lost without a Star. This forum is the very proof of that.
Anyway. What is in effect a few hours spent eliminating possibilities/diagnosis we know that the LT is not switching the HT at the starter motor solenoid.
It would seem likely we have an EIS failure or similar. By all means measure LT voltage while cranking & take a piece of wire from battery POS terminal to starter solenoid as previously suggested to confirm.
An Indy without a Star would have had to do exactly as you have.
This fault has been slightly more complex. Any competent dealer will tell you that 99% of no crank situations on the W203 is caused by an underated fuse 52 at 15A instead of 20A having blown.
Holmes likes sniping from the sidelines or giving monosyllabic answers or suggestions. I have never seen him provide a clear & really helpful post that walks the poster, in layman's language, through solving a problem on these cars. Diagrams, pictures & all to simplify.
Members helping members on this forum has saved them many thousands of dollars.
Last edited by Glyn M Ruck; Aug 8, 2014 at 11:10 AM.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
