ECU Failure - Rattling ECU (ECM - ME)
10-14-2012, 09:11 AM
#1
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ECU Failure - Rattling ECU (ECM - ME)
Anyone ever had a ECU Failure?
Seems my "Coolant Visit Workshop" - Kill Engine Signal (stall and won't start) - Front Radiator Engine Fan Spinning In High Mode Like Turbine Engine,... and car stopping by itself (or it seems) were all caused by a ECU (Engine Control Unit - aka ECM Engine Control Module - ME Motor Electronic) failure.
** "Coolant Visit Workshop" when driving the car:
- "Coolant Visit Workshop" malfunction error on instrument cluster display - usually followed by "ESP Visit Workshop" and a third Visit Workshop message for Engine, ABS or Display
- car goes into Stalls (lost power steering, no acceleration, slow automatic braking done by car and when car stops engine turns itself off)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out and Front Radiator fan stays on in high mode (sound like a turbine engine) for another 30-50 seconds
*** "Coolant Visit Workshop" when trying to start the car:
- Key in position 1 - everything seems fine and instrument cluster display lights up normally
- Key in position 2 - everything seems ok (as car seems to do its regular checks - 10 clicking sound from engine 1/sec) then Front Radiator fan turns itself on in high mode (sound like a turbine engine) and then "Coolant Visit Workshop" malfunction error displays on instrument display cluster.
- Any attempt to turn key to ignition to start engine is ignored - engine can not start - no starter clicking (nothing)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out within first second and fan will turn off otherwise leave key in too long and Front Radiator fan stays on in high mode (sound like a turbine engine) and when key is finally taken out front radiator fan continues to spin for another 30-50 seconds
More details of my original problems can be found here,...
https://mbworld.org/forums/c-class-w...gh-mode-2.html
NOTE: When front radiator engine fan control module does not get a signal from ECU, the front radiator fan will start spin in high mode (like a turbine engine) as a default. It is a safety feature, it assumes the worst,... that the engine is overheating and must be cooled down. The question is,... why is the ECU not communicating,...
My Mercedes Indy (McNally Auto) went through all the electricals like CSI and tracked down my problem to a ECU that no longer communicates,... it doesn't power up,... took out the ECU and it RATTLES,... the ECU is a circuit board for the Motor Electronic and is in a sealed water tight module beside the air filter housing.
Why does my ECU rattles,... it could be that one of the capacitor or resistors on the circuit board broke loose,... or one of the 4 screws holding the circuit board came off by itself (in which case it is just a new way of me getting "screwed"). As soon as the car is fixed and I get the old ECU back,... I will be ripping it apart to find the source of the rattling.
My car only has 63,956km (39,740miles).
Sometimes ECU are messed up when someone "tune" the ECU for performance improvements,... my ECU was never tuned, flashed, chipped or altered in anyway. A short in main wiring harness can lead to ECU failure. Common faults are like blown output stages (no power to injectors) which is generally easy and cheap to fix. Complex issues like damaged EEPROM (bad tuning-flashing) or faulty ECU programming are more expensive to fix. ECU replacement usually happen due to leaking cam magnet sensor (I had a bit of oil at cam magnet but none in main harness wire) because of Mercedes-Benz Dealership would rather replace entire ECU when oil is found in plug rather than to just clean it out (much higher profit margins).
Seems my "Coolant Visit Workshop" - Kill Engine Signal (stall and won't start) - Front Radiator Engine Fan Spinning In High Mode Like Turbine Engine,... and car stopping by itself (or it seems) were all caused by a ECU (Engine Control Unit - aka ECM Engine Control Module - ME Motor Electronic) failure.
** "Coolant Visit Workshop" when driving the car:
- "Coolant Visit Workshop" malfunction error on instrument cluster display - usually followed by "ESP Visit Workshop" and a third Visit Workshop message for Engine, ABS or Display
- car goes into Stalls (lost power steering, no acceleration, slow automatic braking done by car and when car stops engine turns itself off)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out and Front Radiator fan stays on in high mode (sound like a turbine engine) for another 30-50 seconds
*** "Coolant Visit Workshop" when trying to start the car:
- Key in position 1 - everything seems fine and instrument cluster display lights up normally
- Key in position 2 - everything seems ok (as car seems to do its regular checks - 10 clicking sound from engine 1/sec) then Front Radiator fan turns itself on in high mode (sound like a turbine engine) and then "Coolant Visit Workshop" malfunction error displays on instrument display cluster.
- Any attempt to turn key to ignition to start engine is ignored - engine can not start - no starter clicking (nothing)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out within first second and fan will turn off otherwise leave key in too long and Front Radiator fan stays on in high mode (sound like a turbine engine) and when key is finally taken out front radiator fan continues to spin for another 30-50 seconds
More details of my original problems can be found here,...
https://mbworld.org/forums/c-class-w...gh-mode-2.html
NOTE: When front radiator engine fan control module does not get a signal from ECU, the front radiator fan will start spin in high mode (like a turbine engine) as a default. It is a safety feature, it assumes the worst,... that the engine is overheating and must be cooled down. The question is,... why is the ECU not communicating,...
My Mercedes Indy (McNally Auto) went through all the electricals like CSI and tracked down my problem to a ECU that no longer communicates,... it doesn't power up,... took out the ECU and it RATTLES,... the ECU is a circuit board for the Motor Electronic and is in a sealed water tight module beside the air filter housing.
Why does my ECU rattles,... it could be that one of the capacitor or resistors on the circuit board broke loose,... or one of the 4 screws holding the circuit board came off by itself (in which case it is just a new way of me getting "screwed"). As soon as the car is fixed and I get the old ECU back,... I will be ripping it apart to find the source of the rattling.
My car only has 63,956km (39,740miles).
Sometimes ECU are messed up when someone "tune" the ECU for performance improvements,... my ECU was never tuned, flashed, chipped or altered in anyway. A short in main wiring harness can lead to ECU failure. Common faults are like blown output stages (no power to injectors) which is generally easy and cheap to fix. Complex issues like damaged EEPROM (bad tuning-flashing) or faulty ECU programming are more expensive to fix. ECU replacement usually happen due to leaking cam magnet sensor (I had a bit of oil at cam magnet but none in main harness wire) because of Mercedes-Benz Dealership would rather replace entire ECU when oil is found in plug rather than to just clean it out (much higher profit margins).
10-14-2012, 08:32 PM
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same here
hey ray is your friend mark "the stalker",I run on the same problem as you,after fixing the shifter problem car was running good!,till I pass it thru a car wash!,since them car has exactly same symptoms as yours, all lights on on dash, fan a full blast and obd2 cant read any codes! (no data link) ,is there a possibility the the ecu is wet?,please keep me posted about the steps you took to fix it,is the second time in two months this car make me walk! thanks mark
10-14-2012, 09:28 PM
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Greetings from the Great White North to Mark,.... the "stalker",... dude you joined 6 years ago and only started posting about a month ago,... even our "resident stalker" Jordan post more often per day than you have in 6 years! (I am just helping C230_Sport_Coup because I owe him one!)
Anyways,.... are you still referring to your shifter problem with the following OBD2 codes:
P0243 Turbocharger Wastegate Solenoid A Malfunction
P0705 Transmission Range Sensor Circuit malfunction (PRNDL Input)
Or are you talking about a new problem,...
You have 02 coupe,... m111 engine,... mine is 03 m271 engine.
First of all ECU failure is very rare,... thats why I am still in shock! One sign of ECU failure is the car stalls or fail to start and the front radiator fan goes just starts spinning in high mode sounding like a turbine engine,... that a default reaction when it does not get any signal from ECU. Its really loud! When exactly does your front radiator fan starts spinning?
Tell me all the steps in details. What happens step by step when you try to start the car,....
Which OBD2 reader are you using,... brand and model, please. Is it timing out or failing to connect.
What happend in the car wash,.... did you have your hood open,... The ECU is a sealed water tight unit,... its right on driver side of air filter housing beside the engine,... where the main harness wire plugs into.
Mark, with key OUT of ignition and car off,.... pull off the main wiring harness plugs from the ECU to check for water,... all the plugs should be water tight as well,.... go through steps in post#10 here:
https://mbworld.org/forums/c-class-w...placement.html
ECU can be fried if there is a short in your main harness,... but it is usually very well protected by fusable links.
This is a pretty detailed log of my experience,... and the steps I took to fix it.
https://mbworld.org/forums/c-class-w...high-mode.html
If your problem is water related,... first I would check for any clogged water drains under the hood. Especially at the corner of the firewalls,.. on passenger side where battery compartment is,... and also on driver side where Front SAM is, in the big black box where the fuse and relays are. Make sure these area are NOT flooded.
Anyways,.... are you still referring to your shifter problem with the following OBD2 codes:
P0243 Turbocharger Wastegate Solenoid A Malfunction
P0705 Transmission Range Sensor Circuit malfunction (PRNDL Input)
Or are you talking about a new problem,...
You have 02 coupe,... m111 engine,... mine is 03 m271 engine.
First of all ECU failure is very rare,... thats why I am still in shock! One sign of ECU failure is the car stalls or fail to start and the front radiator fan goes just starts spinning in high mode sounding like a turbine engine,... that a default reaction when it does not get any signal from ECU. Its really loud! When exactly does your front radiator fan starts spinning?
Tell me all the steps in details. What happens step by step when you try to start the car,....
Which OBD2 reader are you using,... brand and model, please. Is it timing out or failing to connect.
What happend in the car wash,.... did you have your hood open,... The ECU is a sealed water tight unit,... its right on driver side of air filter housing beside the engine,... where the main harness wire plugs into.
Mark, with key OUT of ignition and car off,.... pull off the main wiring harness plugs from the ECU to check for water,... all the plugs should be water tight as well,.... go through steps in post#10 here:
https://mbworld.org/forums/c-class-w...placement.html
ECU can be fried if there is a short in your main harness,... but it is usually very well protected by fusable links.
This is a pretty detailed log of my experience,... and the steps I took to fix it.
https://mbworld.org/forums/c-class-w...high-mode.html
If your problem is water related,... first I would check for any clogged water drains under the hood. Especially at the corner of the firewalls,.. on passenger side where battery compartment is,... and also on driver side where Front SAM is, in the big black box where the fuse and relays are. Make sure these area are NOT flooded.
Last edited by SunnyRayToronto; 10-14-2012 at 09:49 PM.
10-15-2012, 10:50 AM
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fried ecu
well,no,is not related to the former problem,I fixed that by changing the shifter unit with a used one from ebay,car was running fine till....car wash. this car wash in particular has a system that cleans also the undercarriage,so water under pressure is coming from the floor. now to what the car does: key in ignition turns fine, lites on dash lite up, soon as I turn ing to point 2 fan comes a full blast and dont stop till turn ign off, in the mean time,if you trie to start the car nothing happens, nada, and ,the obd2 is not communicating with the car,and I used this same obd2 on this vehicle with no problems before, what led me to beliebe computer is either fried o not receiving power. I check every fuse and every relay. you said that the computer is close to the air filter but I think mine is in the upper corner were all the fuses are,close to the windshield,driver side. questions: how is the computer powered? is there any test I can do? I search everywhere and cant find anything, the only related problem is the slk people that have the k40 relay problem,but I dont think we have the sasme system, take care
10-15-2012, 12:01 PM
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only runs downhill when push it
what worries me the most is the no data link,I tried another obd2 that also worked before on this car and is the same,fails to connect, so for some reason the computer is not powering, and I discover that the windshield wiper don't work either, since I tried to move it out off the way (the leg of the wiper is on the way to the computer)
10-15-2012, 02:52 PM
#7
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Thread Starter
A short in main harness between fuse and ecu can damage ecu,.... coils are too far.
Your car has a series of panel covering the bottom of the car,... so spraying water from the bottom should be fine.
Check the compartment where your ECU is,.... I guess on m111, its near front SAM, relay, fuse box,... look for a waterline or anything indicating water damage,... clogged drainage in the area.
Check all fuse, relay, grounds, wiring, etc,.... Front SAM and rear SAM has a number of relays, if you are not sure how to test a relay,... number them so you know where they were originally. There is usually at least 2 of a kind for each relay,... you might have to get the other from rear SAM,... but just switch them for another of the same kind (same colour and size),... then try to restart again,... is it the same problem. Keep on doing it until you are positive all relays are good.
When exactly does your front radiator fan turn off,.... how long after you take out the key,.... is that after the front radiator fan has already been spinning for about 5 seconds before you take out the key.
ECU should be well protected by breakers and fuse,... if there is power to fuse in front SAM, ECU should be getting power.
Have you ever "tuned" (chipped, flashed, etc,..) your ECU? Have the car ever been jump started or battery terminal connection switched.
Calling a bad ECU is a really tough call to make,.... I'd look elsewhere first.
Since your front radiator fan is spinning in high mode (default when no signal from ECU),... have you tested the fan? Check it's plug/wirin for water or short.
Use instrument cluster to navigate to coolant/engine temperature display,... what is the temperature? Is it accurate/reasonable? A bad coolant temperature sensor can trigger fan.
Since your wipers don't work,... what about horn and exterior lights? Do they work?
What brand and model OBD2 sanners are you using?
Could the CAN-bus be bad? Does your car have any rust? If so, where?
Your car has a series of panel covering the bottom of the car,... so spraying water from the bottom should be fine.
Check the compartment where your ECU is,.... I guess on m111, its near front SAM, relay, fuse box,... look for a waterline or anything indicating water damage,... clogged drainage in the area.
Check all fuse, relay, grounds, wiring, etc,.... Front SAM and rear SAM has a number of relays, if you are not sure how to test a relay,... number them so you know where they were originally. There is usually at least 2 of a kind for each relay,... you might have to get the other from rear SAM,... but just switch them for another of the same kind (same colour and size),... then try to restart again,... is it the same problem. Keep on doing it until you are positive all relays are good.
When exactly does your front radiator fan turn off,.... how long after you take out the key,.... is that after the front radiator fan has already been spinning for about 5 seconds before you take out the key.
ECU should be well protected by breakers and fuse,... if there is power to fuse in front SAM, ECU should be getting power.
Have you ever "tuned" (chipped, flashed, etc,..) your ECU? Have the car ever been jump started or battery terminal connection switched.
Calling a bad ECU is a really tough call to make,.... I'd look elsewhere first.
Since your front radiator fan is spinning in high mode (default when no signal from ECU),... have you tested the fan? Check it's plug/wirin for water or short.
Use instrument cluster to navigate to coolant/engine temperature display,... what is the temperature? Is it accurate/reasonable? A bad coolant temperature sensor can trigger fan.
Since your wipers don't work,... what about horn and exterior lights? Do they work?
What brand and model OBD2 sanners are you using?
Could the CAN-bus be bad? Does your car have any rust? If so, where?
Last edited by SunnyRayToronto; 10-15-2012 at 03:00 PM.
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10-15-2012, 04:36 PM
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bad bad coil
ok ,first, wipers dint work because hood was open! 
,second, I umpluged the ecu after disconnecting the battery, leave it there for about 15 m,come back and put everything back, and surprise! car started.....
but.....in only 3 cylinders,that's when I found out one of the coils was hot(I disconnected), and by hot I mean almost caching fire!,so I leave it running so everything will be heat up but the engine in case there is some water somewhere but the car shut off itself and now 'I'm back to the same thing, no crank, fan to full,no link. oh, by the way, when the car was running I did get a po705 code, after shutting off no more data link
,second, I umpluged the ecu after disconnecting the battery, leave it there for about 15 m,come back and put everything back, and surprise! car started..... but.....in only 3 cylinders,that's when I found out one of the coils was hot(I disconnected), and by hot I mean almost caching fire!,so I leave it running so everything will be heat up but the engine in case there is some water somewhere but the car shut off itself and now 'I'm back to the same thing, no crank, fan to full,no link. oh, by the way, when the car was running I did get a po705 code, after shutting off no more data link
10-15-2012, 04:38 PM
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ecu
about the ecu being tuned, no by me, and looks virgin from the outside,and I did find some moisture that I blow away with the compressor ,obd2 is a cheap actron from o'reallys,but works fine
10-15-2012, 06:03 PM
#10
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I really can not stress this enough,... but ECU faults are extremely rare. For me to have one and you too,... that's like lightning striking twice,... with those type of odds, we need to race over to the lottery booth! Oh, I keep forgetting,... we're actually having bad luck!
Even at my Mercedes Indy,... they're really busy with about 8-10 mechanics and 12-15 service bays,... they might see about 1 ECU failure a year,... usually after someone does something really stupid,... like reverse their battery terminal.
The Mercedes parts manager (at a busy Toronto area MB dealership) says he typically see orders for about 1 or 2 ECU in an entire year,....
Keep in mind, there`s no cam magnet sensor recall in Canada,.... in USA, they will replace ECU at the slightest sign of oil at the ECU plug vs cleaning with electrical cleaner,... its called profit margin.
Even at my Mercedes Indy,... they're really busy with about 8-10 mechanics and 12-15 service bays,... they might see about 1 ECU failure a year,... usually after someone does something really stupid,... like reverse their battery terminal.
The Mercedes parts manager (at a busy Toronto area MB dealership) says he typically see orders for about 1 or 2 ECU in an entire year,....
Keep in mind, there`s no cam magnet sensor recall in Canada,.... in USA, they will replace ECU at the slightest sign of oil at the ECU plug vs cleaning with electrical cleaner,... its called profit margin.
10-15-2012, 06:11 PM
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bad fricking mercedes
well,I never get it to start again, and the fan keeps coming on as a sign of something wrong, and the only thing I disconnected before was the computer,so is computer related, I may have to take the change and rebuild the computer at a cost of 560, since I dont really want to see this car anymore,this is the most problematic car that I ever have,by far,and I have a lot of cars in my life, I have multiple failures on other vehicles, but they never ever let me down in the middle of the road as many times as this ting that I'm starting to hate, maybe is my last mercedes ever! thanks for you imput, look to this side of town for a torch mercedes!!!!!!!
10-15-2012, 06:29 PM
#12
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When you unplugged your ECU, did you shake your ECU,... is there a rattle,...
To call a ECU failure,... you really need to get a good Mercedes Indy (or dealer) with Mercedes STAR Diagnostic System to diagnose it,....
In my case, my ECU is totally dead,... its not communicating at all,.... except for the rattle! So my Mercedes Indy was 99% sure I needed a new ECU,... to be 100% sure, they needed to hook up a good ECU of the same part number,.... even if it has different VIN it can still communicate,... even though it would not start the car.
What is your location,....
To call a ECU failure,... you really need to get a good Mercedes Indy (or dealer) with Mercedes STAR Diagnostic System to diagnose it,....
In my case, my ECU is totally dead,... its not communicating at all,.... except for the rattle! So my Mercedes Indy was 99% sure I needed a new ECU,... to be 100% sure, they needed to hook up a good ECU of the same part number,.... even if it has different VIN it can still communicate,... even though it would not start the car.
What is your location,....
10-15-2012, 07:15 PM
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bad mec
Jacksonville Florida, yes take the ecu off the car, no rattle, no communicating with the 3 different obd2 that I put on, even take the cover off the back of the ecu and dint see anything out of ordinary, try everything but offering a dead body to the Mercedes god, star will not communicate either since no obd2 can hook up
10-15-2012, 08:49 PM
#14
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STAR is better than OBD2,.... STAR will read Mercedes specific fault codes, see log, tell you which subsystems are working, how well they`re working, etc,.... target troublespots and suggest possible fixes,...
Better to pay for a diagnosis with STAR than to give up on a low fault expensive item like ECU
At that price, I would shop around for a rebuild ECU if it comes to that,... it might be better just to get new ECU.
Go though the basic no start checks,.... do you hear solenoid, is there fuel pressure, fuse 52 to 20A, CPS good, etc,...
Better to pay for a diagnosis with STAR than to give up on a low fault expensive item like ECU
At that price, I would shop around for a rebuild ECU if it comes to that,... it might be better just to get new ECU.
Go though the basic no start checks,.... do you hear solenoid, is there fuel pressure, fuse 52 to 20A, CPS good, etc,...
10-15-2012, 08:56 PM
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no even the best reader in the world will read any codes when the computer no communicates,that is one of the symptoms of a bad computer,at the rate that Mercedes dealers charge you I will reach soon enough the 500 buck that the shop charge me to fix my computer, there is no connection between obd2 and computer. did you notice that nobody else have anything to say here about this issue? if I were a blonde with big **** I'm sure ill have 1000 answers! lol
10-15-2012, 11:08 PM
#16
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I think it has more to do with the fact that ECU failure are so rare,.... few would have experienced it to know what they`re talking about.
BTW,.... what`s your sign,.... Blondie!
Yes, I know its hard to tell with me wearing these dark sunglasses,.... but I am really looking into your eyes,... really, I am,... really,...
BTW,.... what`s your sign,.... Blondie!
Yes, I know its hard to tell with me wearing these dark sunglasses,.... but I am really looking into your eyes,... really, I am,... really,...
10-16-2012, 06:10 PM
#19
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CLK had similar symptoms but theirs was caused by short in a cable from ECU to front radiator fan and needed a pigtail harness. Search.
Also make sure OBD2 port has good connection,... you may have to remove some of the plastic housing so your OBD2 plug can go in all the way,...
Also make sure OBD2 port has good connection,... you may have to remove some of the plastic housing so your OBD2 plug can go in all the way,...
10-16-2012, 06:12 PM
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Hey Todd,.... how'd ya dig up my family photo? 
Ah,... stubby beer bottles and tuques,... those were the days, eh!
Todd,... take off, eh!
Ah,... stubby beer bottles and tuques,... those were the days, eh!
Todd,... take off, eh!
11-02-2012, 04:25 AM
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600sl
600SL same issue!
[QUOTE=SunnyRayToronto;5395072]A short in main harness between fuse and ecu can damage ecu,.... coils are too far.
Hi,
I came across your posts while researching my car problem. Symptoms are same as yours, motor does not crank, ESP defective, visit workshop and cooling fans run full speed. I live in Dubai and the dealership just took my car in yesterday but still have not had time to look at it. based on your posts I now suspect the ECU. It will be interesting to see what the dealer comes up with. Did you replace the ECU or send it to ECU Technologies for repair? Mine is a 2005 600SL with 60K kms. It was fine one day and next day in my garage did not crank and displayed the ESP and Fan symptoms. I guess typical of electronics. Regards Greg.
Hi,
I came across your posts while researching my car problem. Symptoms are same as yours, motor does not crank, ESP defective, visit workshop and cooling fans run full speed. I live in Dubai and the dealership just took my car in yesterday but still have not had time to look at it. based on your posts I now suspect the ECU. It will be interesting to see what the dealer comes up with. Did you replace the ECU or send it to ECU Technologies for repair? Mine is a 2005 600SL with 60K kms. It was fine one day and next day in my garage did not crank and displayed the ESP and Fan symptoms. I guess typical of electronics. Regards Greg.
11-02-2012, 12:52 PM
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When engine does not crank or stall and front radiator cooling fan start spinning at high speed,.... the fan is working properly,... that is the default mode when it does not get any signal from ecu (it assumes the worst, that engine is overheating or on fire and spins in high mode to cool everything off),... thus do NOT replace the fan.
First question,... have your ECU been tuned,... My ECU has never been tuned. I have 64,000 km on mine,.. similar to your 60,000 km,... it would have been within the 80,000 km Mercede-Benz warranty but way past the 4 years warranty period,... thus not covered.
Second question,... does your ECU rattles,... I will post more about it in the next few days.
To call a ECU fault,... they really need to hook up to STAR,... to see ECU is non-communicative (dead),... and eliminate other possibilities by checking the wires of the main wiring harness, wires to fan, CAN bus, fuse, relays, etc,...
I actually brought a new ECU from Mercedes-Benz.
BTW, its great, somebody actually uses the search function around here!,... I`ll post more about ECU over the next few days,... so there will be a reference.
First question,... have your ECU been tuned,... My ECU has never been tuned. I have 64,000 km on mine,.. similar to your 60,000 km,... it would have been within the 80,000 km Mercede-Benz warranty but way past the 4 years warranty period,... thus not covered.
Second question,... does your ECU rattles,... I will post more about it in the next few days.
To call a ECU fault,... they really need to hook up to STAR,... to see ECU is non-communicative (dead),... and eliminate other possibilities by checking the wires of the main wiring harness, wires to fan, CAN bus, fuse, relays, etc,...
I actually brought a new ECU from Mercedes-Benz.
BTW, its great, somebody actually uses the search function around here!,... I`ll post more about ECU over the next few days,... so there will be a reference.
11-03-2012, 03:28 PM
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Dealership service rep called me today to say it was a ECU and to replace it, cost 15,000 AED (4000 USD) with labour, after discount 2990 USD. He went on to say that they cleane dthe ECU connector and that my car started and no other faults. I'm not ready to condemn my ECU if it is working now. I will collect the car tomorrow. He also said they would upgrade the software, but I will call him first thing and cancel that too, I'm sure that will not be free of charge. Is it normal to upgrade the ECU firmware? I will see how the car runs now that the ECU connector has been cleaned. I can also send my ECU for repair or my new at much better than Dubai prices. I'll let you all know how it goes tomorrow.
11-03-2012, 04:38 PM
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My understanding is the new ECU will come from Mercedes-Benz,... VIN (serial number) coded with latest firmware on it,... dealership (or well connected indy) will have to SCN code it so ECU will be able to communicate with other computer modules on car (ie TCU, EIS, etc,...).
What is wrong with your ECU,... is it just oil in connector that has to be cleaned,...
For W203-CL203 with M271 engine like mine,.. a common issue is leaking oil from cam magnet sensors,... oil get to ECU connector via main wiring harness,.... MB dealership will usually want to change ECU (profit margin) vs just cleaning ECU connector and main wiring harness with CRC QD Electronic Cleaner.
If your car is now running with old ECU,.. I would not replace it,... ECU are very low fault items,.. ECU are basically bullet proof! You need to figure out why your ECU did not work before,... if its just oil causing bad connection,.. clean oil and figure out where oil come from.
Ask how much to update firmware on old ECU,...
What is wrong with your ECU,... is it just oil in connector that has to be cleaned,...
For W203-CL203 with M271 engine like mine,.. a common issue is leaking oil from cam magnet sensors,... oil get to ECU connector via main wiring harness,.... MB dealership will usually want to change ECU (profit margin) vs just cleaning ECU connector and main wiring harness with CRC QD Electronic Cleaner.
If your car is now running with old ECU,.. I would not replace it,... ECU are very low fault items,.. ECU are basically bullet proof! You need to figure out why your ECU did not work before,... if its just oil causing bad connection,.. clean oil and figure out where oil come from.
Ask how much to update firmware on old ECU,...
11-04-2012, 02:27 AM
#25
Super Member
Thread Starter
The source of my ECU problem,...
As soon as I got my old ECU back,... I ripped it apart,.. and my Mercedes Indy Aidan & Charlie McNally helped too! Oh, its a ***** taking that housing case off the sealed ECU. The source of that rattling sound was the Crystal Oscillator (used to provide a stable clock signal in ECU,.. its like the drummer or conductor providing the beat for the music,... Oh, its a Mercedes,.. thus, its like the conductor wand keeping the beat for the orchestra),... the Crystal Oscillator broke off from the ECU circuit board.
NOTE: A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. This frequency is commonly used to keep track of time (as in quartz wristwatches), to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers.
http://en.wikipedia.org/wiki/Crystal_oscillator
The Crystal Oscillator looks like a metallic Tylenol pill,... which is appropiate, since it's given me such a headache! Two metal feet protude from it and are soldered onto the ECU circuit board,... the feet look like they just rest on top of the solder points,... there's no solder on top of the feet, it only connects on the bottom. The holder that holds the crystal oscillator to the ECU circuit board has parts that wrap around the side of the crystal oscillator and two little metal stopper at the top that stops it from going up?,... Huh, this looks like bad design, these metal stoppers should be at the bottom to stop it from falling down,.... haven't they heard of gravity? Seems like the ECU circuit board designer assumed that the ECU plugs are at the bottom,... but infact for the M271 engine, the ECU plugs are at the top. Anyways, because these little metal stoppers are on top,... and since ECU is attached to air filter housing in top of supercharger and right beside m271 engine,... there's vibration. This vibration will be constantly banging on top of the crystal oscillator via the metal stoppers on top. Thus weakening the solder joints at the crystal oscillator feet. After examining my ECU, I am wondering why this is not a more common problem. Maybe it is just my ECU that got the poor soldering joints at the crystal oscillator feet (which are just soldered to the very top of the solder),... but its all done by robotics so there should be more,... I suspect, this is exactly what happened to ctC230K a few years back,... when his ECU just blown itself off like a light bulb all the sudden not working.
https://mbworld.org/forums/c-class-w...ont-start.html
A reminder of my problems:
** "Coolant Visit Workshop" when driving the car:
- "Coolant Visit Workshop" malfunction error on instrument cluster display - usually followed by "ESP Visit Workshop" and a third Visit Workshop message for Engine, ABS or Display
- car goes into Stalls (lost power steering, no acceleration, slow automatic braking done by car and when car stops engine turns itself off)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out and Front Radiator fan stays on in high mode (sound like a turbine engine) for another 30-50 seconds
*** "Coolant Visit Workshop" when trying to start the car:
- Key in position 1 - everything seems fine and instrument cluster display lights up normally
- Key in position 2 - everything seems ok (as car seems to do its regular checks - 10 clicking sound from engine 1/sec) then Front Radiator fan turns itself on in high mode (sound like a turbine engine) and then "Coolant Visit Workshop" malfunction error displays on instrument display cluster.
- Any attempt to turn key to ignition to start engine is ignored - engine can not start - no starter clicking (nothing)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out within first second and fan will turn off otherwise leave key in too long and Front Radiator fan stays on in high mode (sound like a turbine engine) and when key is finally taken out front radiator fan continues to spin for another 30-50 seconds
https://mbworld.org/forums/c-class-w...high-mode.html
My stalling and non-start condition originally came and went for a while,... so I guess that was caused by the loose connection. Thus if you have M271 ECU Mercedes-Benz part# A203-153-27-79 and you experience the following conditions on a come and go basis (not permanent),.... then I would strongly suspect a loose connection at the solder joints for the cystal oscillator. When its intermediate,... its relatively simple to fix (VS the cost of new ECU or ECU repair, you really have nothing to lose),.. take out the ECU via MAF DIY style to remove airbox housing to which ECU is attached,... then carefully break open watertight rubber seal of ECU (this will take some time),.... examine solder points of crystal oscillator,... resolder crystal oscillator to circuit board. Reseal ECU with good quality automotive seal.
If I had done the above repairs myself when the problem was intermediate,... then it should have solved my issues. Problem was, I never suspected the ECU,.... the ECU is a very low fault item,... its basically bullet proof!
Eventually,... my problem became permanent,... and I could not start the car at all,... the crystal oscillator broke off from the ECU circuit board and that caused the rattling when the ECU was shook. By this time, when STAR was connected, there was no communication from the ECU. I am guessing with the crystal oscillator (with metallic body) moving around the ECU circuit board, it caused a short or ground out on the ECU circuit board somewhere and fried one or more of the chips. What as originally an intermediate come and goes problem,... was now a permanent no start condition.
Anyways, it seems like it would be very simple to just resolder the crystal oscillator back onto the ECU circuit board,... but I suspect there were other damage to the ECU circuit board (short or ground out). And since this old ECU (A271-153-27-79 Siemen 5WK90451 [08]) has been updated a few times (now A271-153-87-79 Continental 5WK90528 [02]) and I plan on keeping this car for a while,... I figure its better to just get a brand new ECU.
Here are photos of the circuit board for my defective M271 ECU - MB part# A271-153-27-79 Notice, the crystal oscillator in the centre,.. metal tylenol shaped,.. and how poorly it was just soldered to the top of the solder.
NOTE: A crystal oscillator is an electronic oscillator circuit that uses the mechanical resonance of a vibrating crystal of piezoelectric material to create an electrical signal with a very precise frequency. This frequency is commonly used to keep track of time (as in quartz wristwatches), to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers.
http://en.wikipedia.org/wiki/Crystal_oscillator
The Crystal Oscillator looks like a metallic Tylenol pill,... which is appropiate, since it's given me such a headache! Two metal feet protude from it and are soldered onto the ECU circuit board,... the feet look like they just rest on top of the solder points,... there's no solder on top of the feet, it only connects on the bottom. The holder that holds the crystal oscillator to the ECU circuit board has parts that wrap around the side of the crystal oscillator and two little metal stopper at the top that stops it from going up?,... Huh, this looks like bad design, these metal stoppers should be at the bottom to stop it from falling down,.... haven't they heard of gravity? Seems like the ECU circuit board designer assumed that the ECU plugs are at the bottom,... but infact for the M271 engine, the ECU plugs are at the top. Anyways, because these little metal stoppers are on top,... and since ECU is attached to air filter housing in top of supercharger and right beside m271 engine,... there's vibration. This vibration will be constantly banging on top of the crystal oscillator via the metal stoppers on top. Thus weakening the solder joints at the crystal oscillator feet. After examining my ECU, I am wondering why this is not a more common problem. Maybe it is just my ECU that got the poor soldering joints at the crystal oscillator feet (which are just soldered to the very top of the solder),... but its all done by robotics so there should be more,... I suspect, this is exactly what happened to ctC230K a few years back,... when his ECU just blown itself off like a light bulb all the sudden not working.
https://mbworld.org/forums/c-class-w...ont-start.html
A reminder of my problems:
** "Coolant Visit Workshop" when driving the car:
- "Coolant Visit Workshop" malfunction error on instrument cluster display - usually followed by "ESP Visit Workshop" and a third Visit Workshop message for Engine, ABS or Display
- car goes into Stalls (lost power steering, no acceleration, slow automatic braking done by car and when car stops engine turns itself off)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out and Front Radiator fan stays on in high mode (sound like a turbine engine) for another 30-50 seconds
*** "Coolant Visit Workshop" when trying to start the car:
- Key in position 1 - everything seems fine and instrument cluster display lights up normally
- Key in position 2 - everything seems ok (as car seems to do its regular checks - 10 clicking sound from engine 1/sec) then Front Radiator fan turns itself on in high mode (sound like a turbine engine) and then "Coolant Visit Workshop" malfunction error displays on instrument display cluster.
- Any attempt to turn key to ignition to start engine is ignored - engine can not start - no starter clicking (nothing)
- Front Radiator fan turns itself on in high mode (sound like a turbine engine) - stays on as long as key is in - take key out within first second and fan will turn off otherwise leave key in too long and Front Radiator fan stays on in high mode (sound like a turbine engine) and when key is finally taken out front radiator fan continues to spin for another 30-50 seconds
https://mbworld.org/forums/c-class-w...high-mode.html
My stalling and non-start condition originally came and went for a while,... so I guess that was caused by the loose connection. Thus if you have M271 ECU Mercedes-Benz part# A203-153-27-79 and you experience the following conditions on a come and go basis (not permanent),.... then I would strongly suspect a loose connection at the solder joints for the cystal oscillator. When its intermediate,... its relatively simple to fix (VS the cost of new ECU or ECU repair, you really have nothing to lose),.. take out the ECU via MAF DIY style to remove airbox housing to which ECU is attached,... then carefully break open watertight rubber seal of ECU (this will take some time),.... examine solder points of crystal oscillator,... resolder crystal oscillator to circuit board. Reseal ECU with good quality automotive seal.
If I had done the above repairs myself when the problem was intermediate,... then it should have solved my issues. Problem was, I never suspected the ECU,.... the ECU is a very low fault item,... its basically bullet proof!
Eventually,... my problem became permanent,... and I could not start the car at all,... the crystal oscillator broke off from the ECU circuit board and that caused the rattling when the ECU was shook. By this time, when STAR was connected, there was no communication from the ECU. I am guessing with the crystal oscillator (with metallic body) moving around the ECU circuit board, it caused a short or ground out on the ECU circuit board somewhere and fried one or more of the chips. What as originally an intermediate come and goes problem,... was now a permanent no start condition.
Anyways, it seems like it would be very simple to just resolder the crystal oscillator back onto the ECU circuit board,... but I suspect there were other damage to the ECU circuit board (short or ground out). And since this old ECU (A271-153-27-79 Siemen 5WK90451 [08]) has been updated a few times (now A271-153-87-79 Continental 5WK90528 [02]) and I plan on keeping this car for a while,... I figure its better to just get a brand new ECU.
Here are photos of the circuit board for my defective M271 ECU - MB part# A271-153-27-79 Notice, the crystal oscillator in the centre,.. metal tylenol shaped,.. and how poorly it was just soldered to the top of the solder.
The following 2 users liked this post by SunnyRayToronto:
Foondar (03-05-2016),
stenodinson (11-22-2016)
