Alternator burning out ecu?
07-23-2013, 03:07 PM
#1
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06 C230
Alternator burning out ecu?
I've had to replace my ECU twice now. The battery/alt see workshop light comes on before it starts acting up. When I put it in dyno mode it reads 13.5v until i reach third gear then it goes to 14.2 and holds steady. Not sure if these two are connected but could a bad battery burn out my ECU? All fuses are good.
07-23-2013, 06:01 PM
#2
Super Member
BULL SHlT!
First of all,... there's circuit breakers between battery & ECU to protect ECU. A defective battery is more likely to damage front SAM,.... and that's if the person disconnecting and connecting the battery is more defective than the battery.
Any doubt about your battery,... then just replace it,... car battery should be replaced every 5 years!
WTF,... Nobody analyse battery voltage based on gear,.... what's voltage at start, idle, 2000rpm?
First of all,... there's circuit breakers between battery & ECU to protect ECU. A defective battery is more likely to damage front SAM,.... and that's if the person disconnecting and connecting the battery is more defective than the battery.
Any doubt about your battery,... then just replace it,... car battery should be replaced every 5 years!
WTF,... Nobody analyse battery voltage based on gear,.... what's voltage at start, idle, 2000rpm?
07-24-2013, 01:31 PM
#4
Super Member
Voltage tends to be on lower range for a "new battery",... probably didn't go with OEM Mercedes battery. Assuming 13.5V is idle and 14.2V is near 2000rpm,... but like I said,... I've never seen anyone report voltage in 3rd gear,... what's the RPM? If you want people to help then tell us something we'll understand instead of speaking jibberish!
You might think you know how to analyze and troubleshoot,... but your hypothesis and conclusion seems to be lacking.
Since you've already replaced the ECU twice already,.... why? Obviously your analysis and troubleshooting or that of your mechanic isn't very good. Mercedes ECU are basically bullet proof,... very low fault item,.... that said, they do mess up like anything else, but extremely rare. But to have two ECU need to be replaced??? Somebody obviously should have did some analysis and troubleshooting to figure out why the first ECU was replaced (note: I didn't say needed to be replaced),....
The search function is helpful,....
You might think you know how to analyze and troubleshoot,... but your hypothesis and conclusion seems to be lacking.
Since you've already replaced the ECU twice already,.... why? Obviously your analysis and troubleshooting or that of your mechanic isn't very good. Mercedes ECU are basically bullet proof,... very low fault item,.... that said, they do mess up like anything else, but extremely rare. But to have two ECU need to be replaced??? Somebody obviously should have did some analysis and troubleshooting to figure out why the first ECU was replaced (note: I didn't say needed to be replaced),....
The search function is helpful,....
07-24-2013, 11:45 PM
#6
Super Member
I think SeaCoupe subscribes to the same subject matter expertise rule as my workplace,... if you're the last software engineer to code or fix a particular part of the software,... you automatically become the subject matter expert on that part of the software.
That said,... I'm probably the only regular poster on this forum who have ever experience an ECU failure and replacement firsthand. My own experience,...
https://mbworld.org/forums/c-class-w...high-mode.html
https://mbworld.org/forums/c-class-w...cu-ecm-me.html
The only other poster on this forum who experienced ECU failure and replacement is ctC230K on his 2005 C230 over 6 years ago,... and ctC230K got rid of that car about 5 years ago so ctC230K hasn't been around in quite a while.
https://mbworld.org/forums/c-class-w...ont-start.html
So out of all the posters who have ever posted on MBWorld's W203 forum,... only 2 of us have ever posted about our own ECU failure and replacement,... and these W203/CL203 have been out for a dozen years already,...
Are you starting to get the picture,... ECU failure are extremely rare! So rare that my Mercedes Indy (McNally Auto - the best Mercedes Indy in Toronto) with about 15 service bays and at least 10 mechanics only see about 1 ECU failure and replacement in a year. I brought my replacement ECU at my local Mercedes-Benz Dealership in Toronto right next door to Mercedes-Benz Canada's head office,... its one of the bigger Mercedes-Benz dealership in Toronto where Mercedes tend to be quite popular due to our strong finacial service sector and many wealthy immigrants in the Toronto area,... the parts manager asked me a ton of questions to make sure I actually needed a replacement ECU,... because his parts department of one of the busiest Mercedes-Benz dealerships in Canada only sell about one ECU per year!
Are you getting the picture,... ECU failure are extremely rare! They're basically bulletproof,...
Now for your car to have not just one,... but TWO ECU failure and replacement already,... heck, ever,... I'd say with those odds,.... your odds are better at the lottery.
You got to tell us,... exactly why did your first ECU fail and got replaced? Was your ECU ever modified? What were the symptoms? Did the car stall,.. if so, did the front radiator fan spin in high mode like a loud turbine engine? Who made the diagnosis? What tests did they perform?
Same questions for the second ECU,... exactly why did your second ECU fail and got replaced? Was your ECU ever modified? What were the symptoms? Did the car stall,.. if so, did the front radiator fan spin in high mode like a loud turbine engine? Who made the diagnosis? What tests did they perform?
A Mercedes ECU cost about $1000-$2500 for the part plus at least $500 labour for the diagnostic, installation and SCN coding. And if you already had this done twice,... I'd say, your mechanic found himself a big sucker! If this same mechanic is now trying to sell you the third ECU based on bad battery or alternator frying your ECU,.... Let's just say,... even if you simultaneously reverse the connections of your battery while crashing into a high voltage transformer while getting lighting strike during a thunderstorm,.... and your frontSAM ends up being fried to a smoking charcoal crisp as it should in that situation,.... your ECU will still NOT be damaged!
Possible reason for ECU replacement (note: I did NOT say ECU failure):
- The Mercedes-Benz service department might "recommend" ECU replacement due to leaking cam magnet sensor because Mercedes-Benz Dealership would rather replace entire ECU when oil is found in plug rather than to just clean it out (much much higher profit margins),... Gee, bill customer for $1500-$3000 or just use up about a quarter of $5 can of CRC Electronic Cleaner,... We call them Mercedes-Benz STEALERships for a reason,...
Possible reason for ECU failure:
- Sometimes ECU are fried or messed up when someone "tune", "flash" or "chip" the ECU for performance improvements,...
- A short in main wiring harness can lead to ECU failure and even then we're talking like a broken fan belt breaking the right combination of wires in the main wiring harness
- Common faults are like blown output stages (no power to injectors) which is generally easy and cheap (about $100) to fix. Complex issues like damaged EEPROM (bad tuning-flashing) or faulty ECU programming are more expensive to fix.
That said,... I'm probably the only regular poster on this forum who have ever experience an ECU failure and replacement firsthand. My own experience,...
https://mbworld.org/forums/c-class-w...high-mode.html
https://mbworld.org/forums/c-class-w...cu-ecm-me.html
The only other poster on this forum who experienced ECU failure and replacement is ctC230K on his 2005 C230 over 6 years ago,... and ctC230K got rid of that car about 5 years ago so ctC230K hasn't been around in quite a while.
https://mbworld.org/forums/c-class-w...ont-start.html
So out of all the posters who have ever posted on MBWorld's W203 forum,... only 2 of us have ever posted about our own ECU failure and replacement,... and these W203/CL203 have been out for a dozen years already,...
Are you starting to get the picture,... ECU failure are extremely rare! So rare that my Mercedes Indy (McNally Auto - the best Mercedes Indy in Toronto) with about 15 service bays and at least 10 mechanics only see about 1 ECU failure and replacement in a year. I brought my replacement ECU at my local Mercedes-Benz Dealership in Toronto right next door to Mercedes-Benz Canada's head office,... its one of the bigger Mercedes-Benz dealership in Toronto where Mercedes tend to be quite popular due to our strong finacial service sector and many wealthy immigrants in the Toronto area,... the parts manager asked me a ton of questions to make sure I actually needed a replacement ECU,... because his parts department of one of the busiest Mercedes-Benz dealerships in Canada only sell about one ECU per year!
Are you getting the picture,... ECU failure are extremely rare! They're basically bulletproof,...
Now for your car to have not just one,... but TWO ECU failure and replacement already,... heck, ever,... I'd say with those odds,.... your odds are better at the lottery.
You got to tell us,... exactly why did your first ECU fail and got replaced? Was your ECU ever modified? What were the symptoms? Did the car stall,.. if so, did the front radiator fan spin in high mode like a loud turbine engine? Who made the diagnosis? What tests did they perform?
Same questions for the second ECU,... exactly why did your second ECU fail and got replaced? Was your ECU ever modified? What were the symptoms? Did the car stall,.. if so, did the front radiator fan spin in high mode like a loud turbine engine? Who made the diagnosis? What tests did they perform?
A Mercedes ECU cost about $1000-$2500 for the part plus at least $500 labour for the diagnostic, installation and SCN coding. And if you already had this done twice,... I'd say, your mechanic found himself a big sucker! If this same mechanic is now trying to sell you the third ECU based on bad battery or alternator frying your ECU,.... Let's just say,... even if you simultaneously reverse the connections of your battery while crashing into a high voltage transformer while getting lighting strike during a thunderstorm,.... and your frontSAM ends up being fried to a smoking charcoal crisp as it should in that situation,.... your ECU will still NOT be damaged!
Possible reason for ECU replacement (note: I did NOT say ECU failure):
- The Mercedes-Benz service department might "recommend" ECU replacement due to leaking cam magnet sensor because Mercedes-Benz Dealership would rather replace entire ECU when oil is found in plug rather than to just clean it out (much much higher profit margins),... Gee, bill customer for $1500-$3000 or just use up about a quarter of $5 can of CRC Electronic Cleaner,... We call them Mercedes-Benz STEALERships for a reason,...
Possible reason for ECU failure:
- Sometimes ECU are fried or messed up when someone "tune", "flash" or "chip" the ECU for performance improvements,...
- A short in main wiring harness can lead to ECU failure and even then we're talking like a broken fan belt breaking the right combination of wires in the main wiring harness
- Common faults are like blown output stages (no power to injectors) which is generally easy and cheap (about $100) to fix. Complex issues like damaged EEPROM (bad tuning-flashing) or faulty ECU programming are more expensive to fix.
