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Surely not a common engine in USA probablly for W212...yes ?
ADD : I know this is a C class, but its engine is also on a E class. Since I only hang out at the W212 section 99.9% of the time, I parked the thread here ....
Anyhow findings are meant to be shared.
Information on this engine attached as PDF
The story goes like this : I HATE THIS ENGINE !!!! too much low quality plastic used for its air intake system.
Simple joke/critism aside....
I drove to Bali and back Oct to Nov 2021.
So my friend came along with me and parked his 2010 C200 W204 70,000KM at my place.
Upon return from Bali , this car engine running bad ( misfire) for a few seconds and then stalled-DEAD.
3 times trying to start, still the same running bad ( misfire) for a few seconds and then stalled-DEAD.
Battery been charged properly twice a week during the keeping.
Next day, I connected my power supply and do scanning.
Within a few tries, with first 3 tries bad misfiring and then 4th try engine started Okey no misfiring. Hhmm......something fishy here. Something very ELECTRICAL based problem.
Here with this engine ECM called SIM271DE2.0 is my 2nd Mercedes I used my naughty Xentry Pass thru on.
On 19th Nov using Autel , ( The alternator DTC, ignore that Uxxxx code, that is because I disconnected its single LIN wire from ECM.)
I can read more troublecodes.... WTF
Anyhow. I started with the most basic of all......inspect spark plugs , engine air filter and F32 Pre-fuse connection integrity and most grounds connection integrity + ECM wire harness for oil contamination.
This car engine bay is so filty dirty... I spend so much time cleaning it because I do not like working on engine with traces of oil build up.
See how yucky it is :
Aftercooler output to throttle body, that is where the oil traces come from.
Enough of the YUCKY part...
Check for oil contamination on the ECM male pins, all clean.
The main engine ground is so small sized cable !!! So I beef it up with an extra 16mm cable. I don't have 25mm, all I got is a 50mm one
Will continue................
Last edited by S-Prihadi; 12-22-2021 at 11:03 AM.
Reason: add info
Using SCAN ALL I can get troublecode out of the ECM, but if I go to ECM specific page and choose Trouble Code, my naughty Xentry does not want to connect ...weird
SCAN ALL
DIRECT AT ECM PAGE and choose TROUBLE CODE
This never happened to my E400.
Anyway, I have ordered the genuine Tactrix, hopefully late Jan 2022 I can get it.
I suspect the clone Tactrix is not a 100% capability of the genuine one and hence it get hiccups for the older W204..... maybe.
.
I believe this car is assembled locally.
Found a misplaced wire assy squeezed by battery tray, fortunately cable not wounded...yet.
Plugs worn out, the expensive small alloy tip gone, left only the fat base. 70,000KM old for sure.
Gap has expanded to 0.95mm+. Replaced them all with MB original new ones ( 0.8mm gap ).
Black soot at plugs inevitable, this engine is not running properly.
Boroscope the 4 cylinders to see if any of the liners are bad. All good, decent.
Below is a sample from cylinder no 4
Air filter replaced too. Too dirty.
Now with firing (plug) and breathing (air filter) as new, I want to know what actually happened at the combustion chamber, when from cold ( 30C ambient temp ) , WHY it takes a few tries with heavy misfiring and then waiting some time
and try cranking again will make engine idle normal no misfire. Yes, new plugs and air filter produce the same result, but quality of idle is a bit better.
So, typically 1st time cranking try will produce up to 3 dead coils, no firing. Hence engine will be "running" with massive misfire/shake and in 2 seconds died.
Below is a 2 coils only not firing. Engine can idle with shake better than Mambo no 5. **
**
ABOVE : Trigger signal for coil no 3 lost later on. Ony coils 1 and 2 are firing, based on current ramp. This is a cylinder 3 reading, for its trigger ( channel B in red ).
After a while, the engine then decided to behave properly and idle well. Azz-hole !!!
EDIT : 23rd Dec 2021 -- Information correction
This is NOT an automotive scope so there are VERY IMPORTANT differences.
01. MOST IMPORTANT , the ground is a common ground between both chanel A and B. This can be BAD if used wrong on device/s with negative/ground trigger and more than 1 channel used.
Unlike PICOSCOPE 4425A , a true automotive version , which it is a 4 channel with floating/isolated ground. There is also 4225A a 2 channel version, but not worth to get a 2 channel version.
02. Maximum voltage is 20V, no worry can buy a cheap Hantek 20:1 attenuator and it then can handle 400V. Unlike its automotive one 4425A/4225A which is 250V standard.
03. Buffer memory is SOOOOOO SMALL, only 16 KS ( 16,000) . 4425A has 200 M ( Two hundred million ) samples. This one matters a great deal for capture needing bigger buffer memory.
04. Vertical resolution is only 8 bit, damn, the real automotive scope from Pico, the 4425AA is a 12 bit and has filters https://www.picoauto.com/products/au...e-kit/overview
8 bit is 256 data points, 12 bits is 4,096 data points. One loose fine voltage or amperage or signal magnitude details if only on an 8 bit.
My 2205A or 2204A ( more popular) are good starter scopes, but 2 channel is way too few and for certain intermittent problems, you best minimum use a 4 channels.
How to maximize the Buffer Memory of this 2205A/2204A, use your laptop memory !!! Set at 200ms and no less. Won't equal the PICOSCOPE 4425A automotive, but it helps a great deal.
Since English is not my 1st language, Dave's dialect is a tough hear/comprehension for me.
I am used to common BBC type British Queen's English if from UK source and I think Dave is Scotish or Irish.... or you know those region with very different dialects.
WILL CONTINUE.....
Last edited by S-Prihadi; 12-23-2021 at 01:22 AM.
Reason: add more info
Next, make sure all 3 wires/cores set to all 4 ignition coils can handle 10 amps load.
T1/1 to T1/4 are the 4 ignition coils.
C4 at the circuit above is a capacitor to reduce whining produced by iginition coils. At one time I feared the capacitor shorted.
I can not find where the hell MB hide the capacitor. This turbo version ECM wiring assy has some wires towards the coils injected molded with rubber and not like the older supercharged version , where ECM cable assy only has usual jacket.
SOB, it makes wire tracing a nightmare !!! But I can read the capacitor value, 920 nano farad....wheewwww.
NOTE : Dont be suprised reading changing Ohms value if a capacitor exist in between positive and negative wire, if we are tracing potential short between these 2 cable with Ohm setting.
Google, how to test capacitor with Ohm Meter ( not capacitence meter )
If Non turbo M271 older version the wiring is easy to trace, see below : Red square below is the C4 capacitor.
The coils are FED directly positive power from fuse 24 and it uses W11 as ground.
When the engine decided to behave aka zero misfire, it will behave well for 45 minutes or so on the road and then MISFIRE !!!!.... Bloody Hell.
I hate this kind of intermittent issue after self recovery by the engine.
Guaranteed 100% of the time ....when engine has been shut down for more than 5-6 hours, misfire will occur at least on 2 cylinders upon the cold start.
I even freeze/cool the ECM to 4 degrees celcius in my fridge, no difference
So was it too cool ( 30C ) or too hot engine bay normal running temp is part of the culprit ?
This section covers a mistake I made, well sort of of a mistake. It is about the Coil On Plug ( COP ) on this M271.860 engine.
It is a 3 wire COP.
.
.
So what is a 3 wire COP ? Attached a PDF of various COP. See its page 31.
In simple explanation, 3 wire COP has its own switching transistor inside the COP. So the Trigger/Command signal from ECM will be a low voltage one usually 5V ( some can be 9V to 12V ) and is a simple signal low current one.
The heavy work load for switching is then handled internal to the COP at its switching transistor...yipee so simple !!....so I thought.
By the time the engine is normal and no misfire, I need to do further testing............
So I need to then look for this Trigger/Command signal at pin 3 of the coil's INCOMING connector plug* ( *ECM wire harness side ).
I made a jumper wire set which allows the coil only to get two connections only : They are for Power (1) and Ground (2) ,
the trigger/Command (3) I connected to scope positive channel B (red).
The pin 3 at the coil itself, I connected it to a DMM ( digital multimeter ) as I do not have more than 2 channels on the scope. Scope's channel A still need to monitor fuse 24 for current ramps of all active coils.
Below photo is cylinder 2, as sample how I wired the test.
CYLINDER 1. The result is SO weird , as such I tried twice and the same result. I am very certain I did not write the file title* ( *also as description ) wrong
How could the coil of cylinder 1 fired with the Trigger/Command disconnected ?
How come coil of cylinder 3 died ? Engine decided to do misfire ??... I dont know.
OK, let me ignore this weird-ness. It seems the Trigger/Command is a 3Volt positive signal.
The dwell time is 3.182 millisecond. Dwell in ignition systems refers to the period of time that the coil is turned on.
So I did the same test of trigger/command wire disconnected from coil, for cylinder 2.
This is where I got handicap with a 2 channel scope. If I have another or a 3rd channel, I will do crankshaft pulse as main confirmation which cylinder is firing based on current ramp of the coil.
All I can see is, ECM did not send out trigger/command signal to coil no 2.
As to which cylinder actually died...I can not guarantee a 100% it is the #2 cylinder.
Same test method, now for Cylinder 3.
Hhhmmm ... why the trigger/command signal looks like that ?
At least I can see that indeed coil #3 died, when the trigger/command is not connected to it.
Same test method, now for Cylinder 4. Whacky result same as cylinder 1.
How could the coil of cylinder 4 fired with the Trigger/Command disconnected ?
How come coil of cylinder 2 now is the dead one ? Engine decided to do misfire ??... I dont know.
More puzzle. So I asked to myself :
01. Is the ECM sensing disconnected Trigger/Command wire to coil and perform some weird strategy ?
02. Did the injector fired or stopped firing by ECM when I removed the Trigger/Command wire to coil ? I don't know, I do not have a 4 channel scope to sense the injector.
The condition is pushing me to suspect the ECM as the culprit and a few of the coils too.
Let's do 1 more test.
Instead of using Fuse 24 to read current ramps for all coils, let use W11 the common ground. The result would be the same, only the amperage will show minues if I do not orient the current clamp to match it.
Started the engine, engine idle well........BUT........... I CAN NOT DETECT CURRENT FLOW AT W11 !!!!! NIL, ZERO, NADA.
Since you have shown us you do not stop for specialized tools, I think you need a good heat/cold gun to accelerate your testing environment and point it to the "next suspect" in your forensic analysis. In the past, I have seen heat/cold-related issues with other manufacturers, and it is honestly a pain to track down especially when not having the appropriate tools, or enough patience to deal with it.
Keep us posted on the solution since I am sure you will find it
Now I wanted to see the Trigger/Command signal from ECM when connector for coil is connected in greater detail, I got to back-probe the coil connector. Oh oh... this looks like a 2 wire COP !!!!!! This is a PRIMARY IGNITION WAVEFORM , but not as pretty as other COP !!!
But how come the voltage spike (magnetic field collapsing ) when the coil is grounded is so low at only 40 volt, all the samples I am seeing are 70V to 300V ? https://www.picoauto.com/library/aut...ge-2-wire-cop/
I the took a closer look at wire sizes for the M271.860 COP.
Damn , the Trigger/Command wire is as big as the positive power at 1.5mm and the "ground" is smaller at 1mm
I then looked at my M276.820 engine iginition system , but a higher grade 4 wire COP.
See how there is a transistor drawn on my M276.820 engine's COP ?
Mine has the switching transistor INSIDE the coil sort of a Smart Coil becasue it can report better than a 2 wire coil. Hence the Trigger/Command which in my engine diaghram is called SIGNAL, only uses 0.5mm baby wire.
My COP has 2 grounds, W11 is the true POWER-GROUND using 1.5mm wire same as POSITIVE-POWER and the W16/5 is another "ground" using 0.5mm. I think the W16/5 ground is more for noise control.
So, the M271.860 is the old fashion DUMB coil, a 2 wire coil in reality.....where the switching transistor is at the ECM, not at the coil. Its W11 ground is noise control, hence there is a Capacitor C4 for it.
The ATZUE* trigger/command at 1.5mm wire size is the NEGATIVE POWER or POWER-GROUND coming from the ECM.
So this is my mistake here. I assumed MB wont use low cost DUMB 2 wire COP. , for a 2010 car.
I was clouded with 3 wire COP all day long. DAMN !!!!
My knowledge of COP is limited in its waveform and I can't access Pico Automotive WaveForm library website without a true automotive scope attached to my PC/Laptop.
Well, lesson learnt !!!
Thank you master Surya for this excellent case study.
Each installment gives a lot to learn to some of us. I wouldn't change one coma to your insightful research. Looking at cars computers through a scope is always interesting. great looking ECU pins
These pins look new, unoxidized with zero dust contamination. Their flat shape does not look like flakey solderless pins but honest soldered.
Your friend is seriously fortunate to have you doctor his engine like no one else can in your neck of the woods.
multiple noise streams: injectors etc...
This clearly shows couple noise thresholds. Mix that with "low-voltage issues" and you enter signal disruption territory.
One thing my "ULEV" ("Ultra Lean Emission Vehicle") 3.2L Honda V6 has done is teach me is about modern misfirings.
I used to think misfiring was a spark issue, that it was poor design of weak COPs, harness drops. But then eventually little by little I got to eliminate it.
Lean mixtures are very easily misfired even with a great spark ignition system. Multiple reasons get combined together to misfire. The computer always keeps pushing the mixture ratio towards lean clean-burn. That's why lean misfirings are a common occurrence because likes to be near the leanest zone.
My tested solution is proper mixture (Prim. O2, PCV) and stable timings (Serp. tensioner, No CAN latency error, Eng/Tran. mounts, VVT) in addition to reliable sparks.
The outcome is great Torque/Pwr with velvet accelerator. This happens when the ECU has relearned a better fuel map that matches engine abilities to burn clean - You can't really cheat with an ECU reset to load neutral values.... the ECU will relearn matched values using the important OXYGEN/LAMBDA SENSOR!
I am sure this crossed your mind regarding the case you described in OP, I'd suspect fuel pumps, filter, pressure sensor, CKP... (I would leave alone "semi-trusted" injectors/rail).
What leads me towards that is "hard cold starts then die" and cold misfires just when mixture needs to be extra rich. Usually that's followed by weak engine torque and the infamous throttle lag.
When the engine is hard to control people are forced to drive with a heavy foot.
++++ Edits: sooted plugs
Spark plug soot guaranties O2/Lambda are contaminated and partially plugged up.... Replace upstream sensor even in absence of O2 CODE (~75kMi)
Last edited by CaliBenzDriver; 12-25-2021 at 02:26 PM.
Yes Cali, those fuel matters and 02/lambda came to mind.
The rear 02 sensor seems sluggish, the front Lambda is not bad. Front Lambda is a wide band one, but not as advance as the one on my E400.
I have already confirmed that the misfire behaviour is not from any input deviation from the Lambda and rear 02 sensor. However it seems the CAT is not as healthy as mine.
The misfire is obvious, when it decided to happen, simple un-plugging the coil/COP connectors will show which cylinder effected.
For bi-directional test, this M271.860 ECM can not be commanded to kill the COP, but can be commanded to kill the fuel injector. I don't know if my M276.820 ECM can be commanded to kill the COP or not , never bother to test.
Camshaft phasor activation/deactivation can be commanded, it is still good, except for the stupid 3 seconds initial knock sound at the cam phasor sprocket itself if engine already hot and we do engine start.
Back to troubleshooting.........
I need to confirm a 100% that indeed this COP is a true 2 wire DUMB one and is negative power is purely from its trigger/command wire ( pin 3 ) , hence it is from the ECM....... and not from its so called ground W11 (pin 2 ).
So I current clamp the trigger/command wire ( Channel A - blue ) and for Channel B-red I read pin 1 positive power to its pin 2 , the W11 ground.
Above confirmed a 100%, this is a 2 wire COP or best to call it dumb coil with grounded trigger from ECM.
For knowledge sake , I also current clamp pin 2 of the coil, I shall call this anti-noise ground. Result is Zero current, same as W11.
This test is also good to do, if any current leak or load occurs/exist at pin 2 of the coil towards Z6/W11/Ground during an ignition current ramp... we do not want that to happen.
Pin 2 from Z6 / W11 I shall describe in simple drawing below
So, I got 4 new COP/Coils.
By now I understood I am dealing with 2 wire COP, I then re-focus on how is the quality of the ignition coil driver inside the ECM.
At this point in time, I am still scope-use-stupid in terms of setting its resolution. Understand that my pico 2205A is of a very low buffer memory and it has no filter function.
Pin 3 of iginition coil , when ECM is not firing or not grounding it or not giving negative power, basically we will be reading system/battery voltage, because pin 3 is only a "winding" away from pin 1 which is fuse 24 and
the ignition primary winding is not yet loaded, so no voltage drop at all.
Simple analogy is below : Borrowed from Fluke website and modified.... LOL
ABOVE : ECM is not firing yet, indicated in green as an open switch. At pin 3 of the COP, we will read system/battery voltage.
When ECM fires the ignition coil, using its driver or transistor or its family of current switching semiconductor yada yada, ECM then connects Pin 3 to ground or gives NEGATIVE power or grounding it.
Since a semicondutor like transistor is not a pure zero resistance mechanical switch, ZERO volt will never be achieved. Same like diode, at least 0.3 to 0.7 volt loss is the best one will get if we use it as a switch ( one way switch/valve ).
So new COP tested. 1.213 volt is what I get. This is rather high, 0.3 to 0.7 volt is what I read I am supposed to get. Make sense for 0.3 to 0.7 volt, I only tested diode voltage drop so far, never mess with transistor though
Anyway, so COP all new, firing or idle quality gets even better. Much smoother.
Test drive again, 30 minutes later misfire again, same issues : more than 1 coil will be disabled by ECM. Reset troublecode using scanner, all good again.
Well.... the main culprit seems 90% is the ECM now.
I forgot to emphasize,
- the misfire occuring will produce engine check light sometimes but not all the time.
- the engine will keep misfiring until we clear the trouble code, the funny part is, the trouble code is not a CURRENT one, but a STORED/HISTORICAL one
A STORED DTC should not make engine behave like a sick puppy, a CURRENT one yes.
So dig up my photo files trying to look for the very first DTC before I use the Autel. That is 17th Nov 2021.
Hhmmm, this code never ever pop out again after that day.
1st day I troubleshoot this car, its historical information from my friend was as follows :
If the car has not been used for sometime, say a week, it will shake and engine poor power for a while and then it will be OK. Those are his simple words, he does not understand MISFIRE. This behaviour been like a year ... DANG !!!
I did all Live Data yada yada test on the Xentry on the 1st day after engine decided to be NORMAL and indeed all values are normal.
With new COP ( also spark plugs and clean air filter ) and WHEN THE ENGINE IS BEHAVING WELL.... the only part I do not like is the response of the rear 02 sensor or maybe the CAT itself.
My friend does at best 4,000 RPM as his WOT. He almost never redline his engine. This is not good for the CAT.
Assuming the rear oxy-sensor temperature is accurate* enough ( *it is a calculated temperature, not a true thermal probe exist in th oxy-sensor ), my frriend's CAT need my kind of driving to make it rather normal.
His AFTER CAT ( rear oxy-sensor CAT 1/2 ) temp difference to the front Lambda ( BEFORE CAT ) sensor is too high. In fact his AFTER CAT temp is too hot. The BEFORE CAT is the one should be slightly hotter.
His AFTER CAT temp must cycle up and down along with BEFORE CAT, not kinda stuck like the data logging shown.
Granted this reading is still within the period his engine misifiring saga is not SOLVED yet. Perhaps too much un-wanted stuff in his CAT from poor combustion. I hope so.
Normal relationship for BEFORE CAT and AFTER CAT temperature is like above.
=========================
So, final verdict is ..... a new ECM required !!!!
I never bothered to check official brand new price from MB Indonesia, as I know US$5K is approx it will be. Local ECM price is a killer. Audi's transmission computer is sold here 300% compared to those in Germany.
My friend just got his 2012 CLS63 AMG a small/secondary computer at the transmission replaced and it cost him US$4K and 45 days waiting period from MB Indonesia.
Not the main transmission computer, I was told. Some special AMG SpeedShift extra module ????
So next LOCAL options are :
- Buy used one from wrecked car. Genuine. No warranty. 1st day when tested OK, deal closed and bye bye no warranty. Price US$1,200 to 1,300 including cloning the data content.
- Buy new one but China made ECM, I guess its a hardware clone version. US$1,300 with data cloning from original ECM. Warranty 6 months.
The China made one I asked my Indie : his clients (with older cars past 10 years old usually ) many has choosen the China-New-Clone ECM and oldest use so far been 2 years and no issue.
SIM271DE2.0 ECM going kapoot is quite common I was told. There are a few Indonesian youtube video showing this ECM.
So I ask my friend : CHOOSE YOUR POISON....
He said, he will keep the car at max 2-3 more years, so go for the CHINA-NEW-CLONE one
Oky Doky............... it shall be then !!!!!
yep, all of our VVT will fail that way eventually. This is a long term WILL-WEAR-OUT-FOR-SURE-100%-GUARANTEED component.
It is done already......... , read here : https://mbworld.org/forums/e-class-w...ml#post8473260
The M271 I speak of in that post is this same one with ECM problem ...
So, China-Clone-ECM ............. how does it look like ?
With red tape is original ECM
Printed as REFURBISHED. Smart azz the manufacturer is, I think that is for escaping legal liability of copyright or reduced import duty to some countries, or BOTH
.
So how does this ECM performed ?
So far so good, but not enough road hours applied to it yet.
Msifire gone, ECM now well behaved.
So the old ECM is an intermittent junkie.... LOL. When it decides to get HIGH, high it will get.
Because my friend's car felt so "aged" to me, I told him, let's do 100% fluid change and fix the freaking cam phasor sprocket which produces the knocking sound for 3 seconds upon start up when warm.
All non fluid components, genuine Mercedes.
01. Engine oil change & engine oil filter. Fuchs TITAN Supersyn SAE 5W-40. Has MB approval 229.5. DONE
A 271 180 05 09 oil filter with o-ring kit. DONE
02. Transmission oil change + filter change + gasket change. Screws use the same old one.
This is a 5 speed, so not the FE type oil. Fuchs TITAN ATF 4134. Has MB approval 236.14. DONE
Gasket, oil pan transmission A 140 271 00 80 . DONE
Trans oil filter A 140 277 00 95 . DONE
There is a story here. My friend has his own usual Indie garage/workhop who maintain his car based on Kilometers and year.
I requested his maintainance record to see how his car been maintained. At 62,229 km 21st Sept 2020 trans oil change was performed. Now the car is 70,600KM there about.
Supposedly 8 liters of Mercedes ATF oil used. I do not know genuine or not, and I do not see any oil filter included.
Among other invoices/work I saw inspection on suspension parts conducted 24th May 2021 and at 67,926 KM. Bullshi-et, how come they never spotted the torn rubber of the Caster Arm ( both ) and the
torn rubber boots of both the left and right side stablizer link ???
So me got to confirm that the trans oil change was probably semi-bogus too.
This is the supposedly 15 months old, less than 10,000KM trans oil below. Yes the pail used is dirty at my Indie, but the trans oil color is a dead give away that my friend was conned.
The typical con naughty workshops do is, only drain out enough at the oil pan, using only the drain plug and never touch the oi filter and never drain out the torque converter. Only 4 liters dirty oil maximum one can take out with this dumb-azz-dirty method.
I insisted on trans oil change because I can feel the trans shifting and behaviour is CRUDE. I am hyper sensitive for mechanical feel of a car. This oldie 5 speed trans uses a service dip stick one can buy, just like engine oil dipstick and the tube is located next to the
engine oil dipstick tube too. So its filling and measuring of oil level is not as difficult as the 7 speed transmission with its small snorkle ( Filling and Removing oil, that small snorkle ) at the oil pan.
03. DIfferential Fluid. DONE. Approx 1.2 liters including dripping loss.
I requested MB 235.7 FE-Hypoidgetriebeöl A 001 989 83 03-* or MB 235.7/ 235.74 FE-Hypoidgetriebeöl A 001 989 33 03-* but it seems I got older number in blue bottle. 1+ years ago when I replaced mine it was grey plastic bottle MB 235.7/ 235.74 FE-Hypoidgetriebeöl A 001 989 33 03-*
70,000 KM and 11 years DIFF oil, does look ****ty.
04. Flush out and replace brake fluid. This one is clean. DONE
MB Dot 4 Plus. 331.0 - Genuine from MB. This year it is steel can based container, I like it better than last few years ago in plastic bottle, those grey ones. Only steel can guarantee super dry brake fluid during unsold shelf life.
Plastic still is kinda semi permeable for water vapor ( gas form ).
5 years un-opened shelf life... not bad. Plastic bottle max un-opened shelf life is 2 years I think.
Special order parts. Just arrived yesterday at my Indie, not installed yet.
- Caster Arm, front Left and Right.
- Stabilizer Link, Left and Right.
- Serpentine Belt A 001 993 78 96 , yeah.... MB Indonesia no stock...LOL.
=================
Still more stories to come for the MISFIRING ......
WILL CONTINUE.......
Last edited by S-Prihadi; 12-24-2021 at 11:59 AM.
Reason: correction of information
Oky doky...Merry Christmas to Juan, Cali and Pierre
Back to the M271.860 engine.
With new ECM.
When all fluid replacement done and ALL NEW timing cam phasors IN/OUT , oil control valves and the chain tensioner installed, engine idle well.
The idle quality in terms of ignition firing and mechanical smoothness has increased dramatically, and so is the noise level of the engine has gone down a lot at idle.
All done at my Indie workshop. Not me , I only do ECM, Coils/COP , spark plug sand the air filter....in November. Dec 2nd and up is when this car is at the Indie.
Test drive the car for 15 minutes, can't do far distance too bad..... alll good.
More idling test at my Indie workshop after the test drive to get the coolant to burp out all its air and all fluid level re-checked again.
And then....... mild MISFIRE happened again. This time only cylinder 1 and it is CURRENT and stay CURRENT even after reset as long as engine is running or re-run.
Swap coil and spark plug ( both new ) with those from cylinder 2. Still ECM register cylinder one mild misfire. I am using misfire count or AUTEL call it by mercedes term PERFORMANCE MONITOR.
Okey, at least this time is good. Troublecode is short circuit and open circuit for activation of coil #1. Two troublecodes basically saying the same thing.
Understand that a 2 wire COP or a true 3 wire COP is not as smart as a 4 wire COP for reporting what went wrong.
In my case, this is a 2 wire COP and it has no electronics components like a 4 wire COP to send out reporting to ECM.
So therefore ECM spitting out 2 troublecodes describing issue with Coil 1 but its a hail mary description as OPEN CIRCUIT & SHORT CIRCUIT too hahahahah.
No worry, I understood what the ECM meant.
So I told my Indie, get the ECM seller to check the ECM and give me a new one.
DONE, next day it was replaced with a new ECM and the Cylinder 1 mild misfire come and go, also always and only cylinder 1.
I also was told the 1st new ECM has no issue.
Oh oh.... oh oh.... while I have tested all cables to igition coils as good and all fuses and its wire to ECM are good and all grounds to ECM as good......... there is only 1 more thing to do.
What I have not done is, re-virginizing ( my term ) the female side of the connector terminal.
I usually only do this if a visual inspection shows significant deformation of the female connector. You would call this BAD PIN FITMENT.
I been wanting to make a tool, which I can machine a male blade to represent the male pin of say an ECM or a COP coil.
It will be like our feeler gauge, but it is not thickness we measure per se, but the quality of the bite or friction of the female connector when we insert ( soft-**** ) the male blade.
It is easy to feel such proper bite of the female connector at say a relay and more so an ATO fuse at front SAM.
Once the connector housing itself has rubber seal, we can't detect female connector bite or pin fitment quality....unless we de-pin all the female connectors out of its connector housing and
try to match it to the male blade at the ECM or COP.
All 4 connectors (female terminals) of the COP are okey, visually. None is looser than the other, if using no 3 from smallest needle of that gas torch tip cleaner.
But I still need to push its middle tounge back to its virgin state if possible.
I bought some connector some months ago, female only, to experiment for just in case I need to rig something.
See the "tounge" I speak of below. This connector below has window for its tounge at the TOP side of the connector.
If there is a window, we can at least push the tounge inwards and re-create the virgin condition, well not 100% like new, but we will get the tounge to grip much better at the
incoming male blade. Damn sound like soft-**** too
The COP female wired incoming connectors I was not able to de-pin, I dont know its lock-blade design/placement. I also do not yet have special de-pinning tools.
However I was lucky, there was a small plastic clip inside the connector which we can remove and it exposes a WINDOW for the tounge.....!!!! yeah !!!
Some connector design has a window but it is blocked by the lock-blade. Lock-blade is for the female connector to sit nice at the plastic housing of the connector. You know what I mean.
The ECM side , this is a nightmare. It is like below and is SOOOO small. There is no way to de-virginize the tounge !!!. There is no window !!! https://uk.rs-online.com/web/p/autom...minals/1361734
Easy to de-pin for ECM female connector though, it uses common plastic lock bar from the connector housing itself.
Number 1 to 4 , represent the COP Trigger/Command cylinders number.
I despise the design of the ECM male pin and its wired connectors ( female). See all white rows are supposedly small female connectors or small load, 1.0mm and 0.5mm wires are the norm.
The fattest wire for the white rows are the #1 to 4 only for the iginition coil which is a 1.5mm ...DAMN !!
The biggest wire for this ECM is only 1.5mm and see how other 1.5mm wires get respectable sized female connectors and hence also bigger ECM male pin, for 1.5mm wires .
Shorter ECM connector : F27, F6, F25 and F22 are all from fuses of the same name. 3 grounds are there too, female connector no 2, 4 and 6 and they become W16/5.
The black long row is of a bigger connector than the white row. The right side vertical black row, get the biggest female/male connector and all of them are 1.5mm wires.
If they are big, I am sure it has the window to push the tounge down when needed. The size of the biggest female connector at the ECM ( vertical black side ) is equal in size to the COP female connector at the COP itself.
Back to the female connector no 1 to 4 for COP trigger/command at the other longer sized ECM connector assy.
Size wise, these 4 female connectors are almost 2.5 - 3 times smaller that those at the COP.
I believed I use the 2nd smallest cleaner needle of the gas torch set and I can feel that the female connectors for COP 1 and 2 are both rather loose, while COP 3 and 4 has higher friction.
It is so small, looking at the female connector body shape need 20x magnifying glass, which i fortunately have...but caused me migrain.. LOL.
Since it has no window, I have no choice but to squeeze a tiny portion of it to create a narrower physical shape of the female connector. As shown below.
I chose the rear side, because if I deformed at the front, this female connector may sit misaglined in the plastic connector assy and the ECM male pin may get
bent trying to penetrate the wrong "hole" sorry, I cant stop joking about this.
With the dumb-azz female connector no 1 and 2 for COP, at the ECM, sorted out..... no more DTC and no more mild misfire. Yipeee !!!
I shall report back when the engine been ran for more than 100 hours or 5,000KM.
So far its been used less than 6 engine hours , after the day I got my friend to take back his car on 15th Dec.
Next time I want to go deeper into this SIM271DE2.0 ECM strategy. Next year.
I want to know these :
01. If and when the ECM detected trigger wire or circuit to COP deemed as OPEN or SHORT and engine is still running, does ECM perform re-investigation at a set interval ?
or... does ECM need the iginition key to be OFF ( recycled ) to re-start the whole investigation process ?
My E400 ECM when I didon-wheel tire balance and did not set the car on dyno mode, due to the requirement of having to set transmission in neutral, meaning key was at least at position 2 (Ignition ON, ready to crank) for a while and
then I set key to position 1 ( Ignition OFF, accessories ON ) and the balancer spin each wheel once but separately, still the ECM defined speed differences at wheels as a problem. ECM wil for a bout 750 to 1500 meters of vehicle travel, cut off my electric power steering and throwing ESP code yada yada. Later on more driving will clear the code as the ECM has detected that all 4 wheels are having the same revolution long enough. So DTC became STORED and not current.
Electric power steering and ESP then came back online. So there is a re-investigation ECM is doing for the DTC/Steering-Limp-Mode it will throw me at, at certain preset time or distance or whatever.
So, until further issue with the M271.860 engine or its SIM271DE2.0 ECM, I let this post hibernate. zzzzz..zzzzz
Last edited by S-Prihadi; 12-25-2021 at 11:07 AM.
Reason: add info
Because of this engine, I finally bought the 4 channel picoscope 4425A.
Also bought many female and male terminals used by MB on engine bay and lots of connectors too.
Electrical issue will happen as the car aged, it is only a matter of time.
I will try to assist you on your M276 misfire thread.
Hello Sir S-prihadi, first of all, you deserve a big applause for such an amazing in-depth study of the M271 ignition! Definitely a good read and saved it for future reference.
I just stumbled upon this very informative thread as I have been troubleshooting a similar misfire issue on my W204 C180 (year 2010 facelift model) which coincidentally has similar mileage of 70,xxx km when the issue first arose, with codes P2304, P2307 and P2310. Also coincidentally, I also had an "alternator fault" warning similar to you (could this be the source of all this electrical issues? )
Anyway, back to the misfiring, I was hoping for a simple fix i.e. ignition coil/spark plug replacement, but the symptoms are pointing towards the dreaded ECM failure, which has been commonly faced by peers driving W204/W212s with similar M271EVO engine and tons of vidoes on YouTube covering the same issue.
Alas, just wanted to know if there are further updates thus far on the performance of the "refurbished" chinese ECM replacement? I'm weighing my options at the moment, as I do plan to keep the car for much longer, however I do not prefer to spend about USD4k on a new ECM from the stealership - which will then fail in another 5-8 years potentially.
I am away in Bali at the moment, till mid Jan 2024. So I can't access my PC at home back in Jakarta..... where all my MB stuff is at and including MB WIS/EPC and my Benz-Ninja Xentry.
So those DTC you mentioned : P2304, P2307 and P2310 I do not know what they are as per Xentry.
I will only trust Xentry description, if the DTC is by an MB car.
The chinese ECM 271 has been good so far, and my friend done 10,000KM on it already and half is long range driving. So it is good.
I checked my own MED 177 ECM, new is only US$1,200 or so if in USA, ECM only. So your M271 ECM would be probably around the same, example below approx US$1,150: https://www.mboemparts.com/oem-parts...05MS04MA%3D%3D
So best you buy NEW and genuine one , coding charge probably under US$500 by independent workshop having xentry or clone xentry or even good Autel or Launch scanners.
Now, you must first confirm by using a scope that your misfires are like my friend's W204 case study, before you target the ECM.
You can do the simple COP swap ( all spark plugs best be new or confirmed healthy and genuine ) as simple diagnostic.
Don't forget to make sure ground wires for COP are clean at their W11 and the undocumented ground wire under the car is clean and tight... battery negative to the suspension strut ground W2, clean and tighten.
You see, since M271 ignition power ( driver ) is from/at the ECM and not at the COP, the M271 ECM ground becomes a very high load one compared to say my M276 where it uses a more modern COP with built-in driver
to handle the massive load COP will consume.
SATISFY proper/good basic electrical connection first , the negative and the positive wires, before targeting the ECM.
12-22-2021, 10:19 AM
. So I asked to myself :
. 
to deal with it.
) the male blade.
)
