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Hi i have been getting a malfunction, or rather multiple that happen at the same time for about a year, i took the car to multiple mechanics and each stated that its really weird. basically what happens when i start the car and drive for no less than 2 minutes, multiple malfunctions happen: -The interior and exterior lights flicker -The screen (the one with radio aux phone...) turns off then on -the steering wheel becomes stiff -i get a warning saying release parking brake even though its off -all door locks suddenly open then close -Abs esp malfunction saying unknown error check manual -2 malfunctions saying left side and right side malfunction (airbags) And thats about it, all happening in less than a minute, then i would drive for 3 hours nothing happens, it only happens when i start the car and drive for first 2 minutes. Sometimes it happens even after i drive for some time and turn off the car then turn on again. also there is a sound that i hear during all these malfunctions it comes from like the fuse box direction like something poped or released idk. i have no idea why all this happens, sometimes it isnt serious its just the screen that turns on and off and lights, and sometimes very serious. Could it be a faulty auxilliary battery or a clogged air filter (read it might be the case and because the filter shakes a lot when i start the car and the ECU is right next to it, the ECU might be affected by the shaking and it goes to normal when i drive and shaking stops).
Hi i have been getting a malfunction, or rather multiple that happen at the same time for about a year, i took the car to multiple mechanics and each stated that its really weird. basically what happens when i start the car and drive for no less than 2 minutes, multiple malfunctions happen: -The interior and exterior lights flicker -The screen (the one with radio aux phone...) turns off then on -the steering wheel becomes stiff -i get a warning saying release parking brake even though its off -all door locks suddenly open then close -Abs esp malfunction saying unknown error check manual -2 malfunctions saying left side and right side malfunction (airbags) And thats about it, all happening in less than a minute, then i would drive for 3 hours nothing happens, it only happens when i start the car and drive for first 2 minutes. Sometimes it happens even after i drive for some time and turn off the car then turn on again. also there is a sound that i hear during all these malfunctions it comes from like the fuse box direction like something poped or released idk. i have no idea why all this happens, sometimes it isnt serious its just the screen that turns on and off and lights, and sometimes very serious. Could it be a faulty auxilliary battery or a clogged air filter (read it might be the case and because the filter shakes a lot when i start the car and the ECU is right next to it, the ECU might be affected by the shaking and it goes to normal when i drive and shaking stops).
Did you find the reason? I got the same problem at my 2012 W204 C coupe
I will add one other possibility- this could occur from a loose/corroded/bad ground. Especially the intermittent parts - works fine, then everything (electronic) suddenly acts up, then it's OK again.
I do not know this model well, and any modern car will have numerous grounds front to rear bumper so I cannot say where to look for them. Often there is a ground in proximity of the ECU in terms of its function and, if loose/corroded, might cause the light shows being seen.
When the car is running and if the ground breaks the circuit, or enough resistance is present to drop the op voltage below threshold, then comes back on, many of these systems reboot/restart and might explain several of the symptoms described above.
I will add one other possibility- this could occur from a loose/corroded/bad ground. Especially the intermittent parts - works fine, then everything (electronic) suddenly acts up, then it's OK again.
I do not know this model well, and any modern car will have numerous grounds front to rear bumper so I cannot say where to look for them. Often there is a ground in proximity of the ECU in terms of its function and, if loose/corroded, might cause the light shows being seen.
When the car is running and if the ground breaks the circuit, or enough resistance is present to drop the op voltage below threshold, then comes back on, many of these systems reboot/restart and might explain several of the symptoms described above.
yep, 110%... bad painted and oxidized GND posts need to checked at least up front. Also alternator voltage and battery charge.
ECU likely grounded in driver footwell area that is subject to rain intrusion.
Same deal with Front-SAM plastic tub that can see moisture and corrosion.
Fixing that car reliably may be a priceless labor of love endeavor.
Keeping the Queen out of rain and direct sunlight is a great practice againt water intrusions ☔
Last edited by CaliBenzDriver; Sep 7, 2021 at 01:35 PM.
Sticking with the "long shot" I mentioned in post #5, I looked up some ground location info on a C180. I think it is the right model, or maybe close to it. Interestingly, there are two ground lug locations that service just about everything on the OPs detailed list. Even the steering angle connector is grounded on W19 and if the ground is failing intermittently might be rebooting the ASR and ESP
It would be interesting to hunt down W19 and check its integrity, and it might pay to check W29/2 as well.
W19 might take a little hunting as the diagram is poor. It might either be under the carpeting alongside the console, or it is possibly under the carpeting on the rocker panel below the passenger door.
Not sure the OP is with us anymore. Looks like he only joined back in Jan to probably solve this problem and I don't think he's posted since. But, if he's out there, would be good if he could report in with an update.
Last edited by Acta_Non_Verba; Sep 12, 2021 at 07:28 AM.
Did you manage to solve ? have the same issue c180 2014 60k kms
Hi SansaElmalo,
Yes, it turned out to be the auxiliary battery located in the rear of the car. Cost me £40 for a Varta equivalent. Hope this helps.
Dean.
Hi SansaElmalo,
Yes, it turned out to be the auxiliary battery located in the rear of the car. Cost me £40 for a Varta equivalent. Hope this helps.
Dean.
Hi Dean, that's good news to read your battery fix.
How long ago did you get the Varta AUX replaced?
Driving voltages have been all good since?
It was about a month ago, but it has been perfect since. I have also just replaced the main battery at the front for peace of mind as it had been in the car from new.
I had all the same issues with the airbag malfunction warnings, release hand brake (when it wasn't engaged) door lock pins would unlock then lock again, headlight symbol on the instrument cluster would illuminate then go out, steering wheel would go momentarily stiff and my infotainment screen would go blank for a few seconds before coming back on again. I also started to get another strange symptom as as result where my turbo would not work, so I would stop at the lights and switch the engine off then back on again and I would see the ECO symbol blip green then back to yellow, but my turbo would then work again for the rest of my journey.
I had the car plugged into my brothers Snap-on OBD reader which seemed to say nothing about battery voltages, maybe star would have given more info. But since changing the aux battery the ECO symbol goes green once more and I have had none of the above issues.
Last edited by DeanoLee; Sep 25, 2021 at 04:04 AM.
Reason: Spelling
Hi SansaElmalo, Yes, it turned out to be the auxiliary battery located in the rear of the car. Cost me £40 for a Varta equivalent. Hope this helps.
Dean.
Hello from just north of Sacramento,
I didn't know about the auxiliary battery located in the rear of the car( I did have the local MB dealership replace the main battery recently - - - but a second unit was never mentioned)
The little C250 coupe is my wife's....................
I looked in the trunk and did not see a battery.
The selling dealer is 8 miles from my home.
Some insight here would sure be appreciated - - - saving me from bothering the busy dealer with a non-issue situation....................
all the best - from a dumb *** in northern California.................
It was about a month ago, but it has been perfect since. I have also just replaced the main battery at the front for peace of mind as it had been in the car from new.
I had all the same issues with the airbag malfunction warnings, release hand brake (when it wasn't engaged) door lock pins would unlock then lock again, headlight symbol on the instrument cluster would illuminate then go out, steering wheel would go momentarily stiff and my infotainment screen would go blank for a few seconds before coming back on again. I also started to get another strange symptom as as result where my turbo would not work, so I would stop at the lights and switch the engine off then back on again and I would see the ECO symbol blip green then back to yellow, but my turbo would then work again for the rest of my journey.
I had the car plugged into my brothers Snap-on OBD reader which seemed to say nothing about battery voltages, maybe star would have given more info. But since changing the aux battery the ECO symbol goes green once more and I have had none of the above issues.
All exact problems are happening that you mentioned at my w204 c180 coupe amg.. (errors, warnings, turbo dying.. )I think I have to change aux battery too.
I didn't know about the auxiliary battery located in the rear of the car( I did have the local MB dealership replace the main battery recently - - - but a second unit was never mentioned)
The little C250 coupe is my wife's....................
I looked in the trunk and did not see a battery.
The selling dealer is 8 miles from my home.
Some insight here would sure be appreciated - - - saving me from bothering the busy dealer with a non-issue situation....................
all the best - from a dumb *** in northern California.................
ez
Hi ezshift5,
Please see attached images of the location and type of aux battery I replaced.
Battery is located under this cover, next to the spare wheel. (Note, you DON'T need to remove the side cover over the fuses.) Battery type. Voltage of old battery.
Last edited by DeanoLee; Sep 27, 2021 at 12:49 PM.
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