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Hello everyone JD here, I've been a member before but something went wrong with my account I guess.... I couldn't log in so I had to create a new one.
I currently own a 2005 e500 pretty much fully loaded some upgrades performance wise. I'll try to keep this short... has anybody encountered seven codes suddenly that all seem tied in electrically. These codes come back instantly on first startup after clearing them p0444, p2027, p2074/p1999, then the four O2 sensor codes p0135,155,141,161
So to give a little info the car definitely is not idling correctly.
I've been a mechanic long time been working on German the last 6 years I've done all the basics as far as checking plugs wires coils fuel injectors compression test will be done today but I'm fairly certain it is not a miss in the sense of a cylinder misfire scanner shows all cylinders within range. Most times the idol will not miss... but more of a Lope like the car has high performance cam?
Any thoughts would be appreciated merry Christmas and happy holidays to everyone!
Last edited by JDVIKING; 01-31-2024 at 03:58 AM.
Reason: Spelling error
Have you checked your fuel trims as well as the temperature of the catalytic convertors? Assuming your charging system is up to scratch Id start looking there.
Yes went thru all that on live data read fuel trims are good within a few hundredth's each bank, Cats are warming correctly all temps within correct range. This happened once before months back then just corrected itself.... I may have did a hard reset on the ecm back then (I will do that tonight) the first tell tale sign last time and now that codes are about to show up *besides the loopy idle is the secondary air pump will NOT come on ...pump is functional when I apply 12v directly and both the 40 amp fuse and the relay are good, checked both ground and lead wires to pump resistance is good. So the I'm assuming the pumps "wake-up" signal under cold start is not being sent?
I should have looked at what the codes were signalling. Other than the O2 codes, the rest are supply side codes - Purge Valve, MAF, etc.
I don't know the answer but my thoughts are:
- Park the O2 sensor codes for a moment - they might be a symptom and not the cause
- Look at the relay for the secondary air pump. If the fuse is fine, and the pump works, that might be the broken link. They're cheap and easy.
- If the relay is fine, then look at your fuel pressure and at least knock that out as a potential problem.
- Look at your throttle flaps. The later version of this engine break them and they stay closed. The linkages are made of plastic and the internals of the manifold gum up with oil from a faulty PCV system/rebreather valve that lets in too much oil. Might be the same for yours
- Clean your MAF. One of the codes indicates a potential conflict between the MAF and the Throttle position sensor
- Disconnect the lines to the evap cannister and see if that makes any difference. One of the codes indicates a purge valve fault. Purge valves can get sticky but you can clean them. Locate it and listen for a ticking sound. It should tick in normal operation. Disconnect the lines going to the cannister and see if that makes a difference.
My approach would be to work out what works and then hopefully you'll find what doesnt. Secondary air pump relay the easy starting point. Hope that helps. Keep us informed please.
Good advice on all of those recommendations Mr. Black ....(hey why can't I be Mr, Black?...."because we have a Mr. Black your Mr. Pink" ...But I don't wanna be Mr. Pink!)
Fuel pressure is good... Secondary air pump ground and power/control wire (red & white) from under hood fuse block is good... Relay is also good (tried 3 relays then checked resistance on them) Cleaned MAF
so I'm moving to EVAP/Purge etc...
More to follow....
I take care of my senior father who is very sick Leukemia & stage 5 CKD being the most urgent... so, I've been short on time. BUT
here's something to get the diagnostic gears turning! So, Pop and I (in the Benz) are on way home from one of his Doc's with check engine light glowing and car
running rough as my last blind date lol. Then....as we're sitting at a red light when the reserve fuel warning pops on and suddenly I realize the car is running noticeably smoother? I pull off a bit hard from the green light for just a few seconds yup....she feels way better! As we still have about 3 miles in semi-stop and go traffic to get home I keep waiting for tease to go away and the washing machine idle to return.
Pops and I even shared a rare laugh together about the constant quirkiness of this "Jinxed car" (his words) as we're pulling in to the gas station (fuel gauge puts me on 2 bars) I pump about 4 gallons in hand Pop a cup of ice cream, and moment of truth....fire her up and yup!! The parties over washing machine is in full effect 😕
But, I'm not upset I new "Benz Hilda" (Yeah I tagged her that name in 2022) wasn't cured suddenly, in fact I'm encouraged ! (Now we're on to something) I had been focused on that dam secondary air pump and why it's not getting signal to engage upon cold start? Also was probing drivers SAM checking resistance, continuity etc)
But I have to believe the smooth running on a very low fuel level followed by the ensuing back to crap after adding the 4 gallons... Lets say after to many years greased up under hoods.... I don't do coincidence..... Thinking psi, flux in tank pressure etc...
No stress re reply. Hope things are going as well as they can with your father.
The fuel level issue is interesting. Theoretically, the engine doesn't know what the fuel level is, so it sounds like a fuel delivery issue. Maybe test for fuel pressure with reserve light on, then with plenty of fuel? You'd think it would be the other way around, but it is German.
The 550s don't have a conventional fuel filter other than what's in/on the pump. Might just be time for a new fuel pump?
Back to your secondary air pump issue, that's triggered by closed loop system/temperature. Maybe investigatation of the temperature sensor makes sense? The cats/exhaust also have a temp sensor and you'd think that's what switches on and then certainly off, the air pump. Maybe it's that which doesn't trigger the air pump to begin with?
Ok so after a stay in the Hospital (Dad) we are home and when time allowed I was back at it....and low and behold I have uncovered the "root cause" ...and why now finally? Simple, sometimes you just need to walk away.....think about something totally unrelated.
Anyway back to the "seven coded serpent" ... Before Pop was released I was relaxing in his hospital room as he was
out like a light when I decide to pull up the wiring diagrams and it hits me I totally forgot that prior to the multiple code issue, the car did have 1 code ...P0155 O2 sensor left side pre-Cat. At the time I did happen to have a new sensor laying around.... yup a $30 "Scamazon" special so of course I threw bad boy in there But only till I grab an OEM...well, I should have known better since it did turn off the p0155 at the time....And that's how you suddenly end up with 7 codes lol...I unplugged that forgotten about POS and 7 codes became 1 code instantly. Now no codes!!
Thanks Mr. Black for your input and time....
the root cause!
Last edited by JDVIKING; 01-25-2024 at 05:35 AM.
Reason: Spelling error
How weird. The dodgy 02 sensor switched off your O2 code but set off 7 others because it didn't actually work. Imagine that, a dodgy part giving you grief! Glad you got it sorted.
This is an interesting hands on repair. I am not sure I totally understand the outcome.
As a mechanic you know that for every parts that are in a pair... change BOTH upstream Lambda (or O2) not just one side. This helps keep the engine balanced.
So you want to replace both upstream with Bosch sensors, reset the ECU, look up LTFT status.
If still faulty, pls expend ECU/PCM/ codes with their english description.
Last edited by CaliBenzDriver; 01-26-2024 at 04:21 PM.
Hey guys first and foremost Dad is back in the hospital so I won't be able to get back on "Benz Hilda" for well.... ? He has covid on top of his existing issues.... Not good!
However quick update I see in my previous text I stated the wrong code P0151 not 155 "WAS" the only code to come back once I disconnected the left pre-cat sensor.
I say "WAS" because that didn't last..... I drove around half the day with that single sensor disconnected (ordered a bosch) but honestly forgot to reconnect it. Although it took much longer, sure enough later that day DTC popped on and yup ...7 original codes came back but having one 02 disconnected is no bueno so really can't rely on recent scan...
More to follow ...Dad is priority now
(the original 7 DTC's are in first post BTW)....... EVAP, secondary air pump are involved side note Mr Black when the codes cleared briefly...The secondary AP did in fact engage and function on the ecm's command.
Firstlt, I hope your Dad gets better soon. Covid is not to be underestimated for older folk.
I was reminded yesterday of how 1 fault can trigger multiple others. My dodgy speed sensor triggered itself and then set off 2 others codes - transmission, cruise control, and one other. But I will get under there to fix it - its only been 12 months.
You did leave out that crucial bit of evidence in your original post - the "I bought it from Evil-bay" admission on the O2!!🤣. It seems we will have to treat you as a hostile witness....
I have heard that of all the dodgy parts you can buy, the 02s are the worst. If you follow Ron Ananian aka The Car Doctor on podcast (great stuff if you havent heard it), pretty sure he said ALWAYS go with a original O2. Now we know why. Best of luck with your Dad.
Sigh.... Things are as bad as it gets...Dad couldn't breathe on his own the Doctors were fighting to avoid incubation, unfortunately they lost that fight ...
Well here I am giving an update on "Hilda" ...But before I do that, Mr Black TY for the support & condolences.
Sadly, Dad passed shortly after the Doctors were forced to incubate him.
So like I had been saying the upstream left O2 turned out to not be the solution.... update when I get back on it.
Cheers
Well it has been a slow process for me Dad's passing hit pretty hard,, reason (as I was afraid of) I never really grieved when my mother passed in August because My father was in bad shape he needed just about 24/7 care and that was me...So I think when he passed an all at once deal...
Anyway some therapeutic Benz talk is just what I need!! So forget the "Magnificent 7 Codes" which are there in force I'm on a new project unfortunately !! A "friend" stuck his little Trump sized hand under my intake manifold and BROKE the extremely bridle and rock hard vacuum hose that runs upward into the BOTTOM of the intake or plenum if you prefer! No short cut fix as it broke right at the manifold She was filthy! started cleaning 1 broken vacuum hose lead to me seeing Alice down this rabbit hole
to make things a little more interesting all 3 items circled in yellow broken or unusable! AND you cant order them, Mercedes calls this a sealed unit
Many rubber hoses were shot...Product of living in the Desert I suppose of course age as well...
Last edited by JDVIKING; 03-03-2024 at 06:01 AM.
Reason: text correction
Sorry i disappeared I wanted to update those who may have similar electrical issues.....After all was said and done it was my "better scanner" that helped finally make progress, As it turns out Benzilla actually had 10 codes not 7 ( don't rely on less expensive scanners like my icarsoft) anyway it's all I had access to at the time, that said the ALMOST fix was the drivers SAM control mod. That actually took care of all the codes! Until the original single code that started the domino of DTC's came back P0151 I will start a new thread as this bugger just won't go away but as the song says 9 outta 10 codes gone ain't bad!
12-27-2023, 05:09 PM
