ABS/EBD inoperative, Limp Mode
05-08-2018 | 07:33 PM
#1
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2012 C250 Sport
ABS/EBD inoperative, Limp Mode
I have a 2012 C250 Sport that I bought new and up until recently had never had an issue at all.
Not long ago I drove about half a mile down the street. On my way there the ABS light and traction control lights came on but the car still ran fine. I started the car to go back home and the check engine light came on then also. I had a scan done at a local indie mechanic and it showed a faulty wheel speed sensor.
Never having had any issues with the car before, I took my sweet time in fixing it and now I'm kicking myself because yesterday when trying to leave, the car was in what appears to be a hard limp mode, as in I crawl along and won't leave 1st gear and maybe 5mph.
Ive been doing some research and have seen that the wheel speed sensor malfunction can cause the engine light as well as the limp mode. It's worth mentioning also that my battery died around the same time that the lights initially came on. It actually took its last breath as I was trying to leave the mechanic shop after getting the codes scanned to diagnose the ABS/EBD light issue. From what I've read, the battery can also trigger these lights, but it's been replaced and since the scan showed a bad sensor I'm going with that as my first/ next step.
I've ordered new wheel speed sensors and they'll be here in a couple of days and it's an easy install so I plan to replace them myself. But what I'm curious about is whether replacing them will automatically reverse the lights being on and lift the limp mode or if I'll have to get a tow to the shop again to have it all reset? If I can do the reset myself, I'm also looking for instructions on how to do this. My last car was an old Mazda, and while I do have a decent amount of mechanical knowledge and feel confident in doing a lot of things, I'm not so used to everything being as computerized as the C250 so my knowledge in that area is a little sparse. TIA!
Not long ago I drove about half a mile down the street. On my way there the ABS light and traction control lights came on but the car still ran fine. I started the car to go back home and the check engine light came on then also. I had a scan done at a local indie mechanic and it showed a faulty wheel speed sensor.
Never having had any issues with the car before, I took my sweet time in fixing it and now I'm kicking myself because yesterday when trying to leave, the car was in what appears to be a hard limp mode, as in I crawl along and won't leave 1st gear and maybe 5mph.
Ive been doing some research and have seen that the wheel speed sensor malfunction can cause the engine light as well as the limp mode. It's worth mentioning also that my battery died around the same time that the lights initially came on. It actually took its last breath as I was trying to leave the mechanic shop after getting the codes scanned to diagnose the ABS/EBD light issue. From what I've read, the battery can also trigger these lights, but it's been replaced and since the scan showed a bad sensor I'm going with that as my first/ next step.
I've ordered new wheel speed sensors and they'll be here in a couple of days and it's an easy install so I plan to replace them myself. But what I'm curious about is whether replacing them will automatically reverse the lights being on and lift the limp mode or if I'll have to get a tow to the shop again to have it all reset? If I can do the reset myself, I'm also looking for instructions on how to do this. My last car was an old Mazda, and while I do have a decent amount of mechanical knowledge and feel confident in doing a lot of things, I'm not so used to everything being as computerized as the C250 so my knowledge in that area is a little sparse. TIA!
Last edited by JulieM316; 05-08-2018 at 07:50 PM.
05-09-2018 | 12:04 PM
#3
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2012 C250 Sport
Thanks for the reply. I don't know the codes unfortunately, was just told it was showing as a wheel speed sensor. I had planned to have them order the part and do the install so I didn't think at the time to get the codes. But now that I'm stranded that would have been helpful information to have..
After I made my initial post I was thinking about the limp mode. Since I've never had this happen to me I wasn't sure how it behaved, but what I'm experiencing is a grinding that you can hear and feel from inside the car but not from the outside. Had a friend pick me up when it first happened and of course he had to roll around the parking lot a little to check it out for himself and I didn't hear anything from outside the car. Is this limp mode a full shutdown of the transmission or just limiting it to partial use to be able to go but just slowly? What I'm experiencing seems to be a full lock down, for whatever reason or cause. I'm also debating the possibility of a seized caliper or something else of that nature, but I'll check those when I have the wheels off to do the sensor replacement. Parts should be here tomorrow.
After I made my initial post I was thinking about the limp mode. Since I've never had this happen to me I wasn't sure how it behaved, but what I'm experiencing is a grinding that you can hear and feel from inside the car but not from the outside. Had a friend pick me up when it first happened and of course he had to roll around the parking lot a little to check it out for himself and I didn't hear anything from outside the car. Is this limp mode a full shutdown of the transmission or just limiting it to partial use to be able to go but just slowly? What I'm experiencing seems to be a full lock down, for whatever reason or cause. I'm also debating the possibility of a seized caliper or something else of that nature, but I'll check those when I have the wheels off to do the sensor replacement. Parts should be here tomorrow.
05-09-2018 | 12:10 PM
#4
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2012 C250 Sport
I should also add that I did the steering wheel turn reset just to see what would happen (turn all the way left, all the way right, repeat). That removed the check engine light and so far it's staying off, but the ABS/traction control set is still on. Of course I haven't been able to actually drive anywhere so I'm not sure if it will come back on. Since I know a sensor is bad I'm just praying that all the other things are related.
05-09-2018 | 12:26 PM
#5
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Joined: Sep 2015
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From: Milwaukee, WI USA
2012 C300 4Matic
"Steering wheel turn reset"? What is that supposed to do? I have never heard of that.
Replace your sensors and see where you are then. If that is all that is wrong you will find out soon enough.
Replace your sensors and see where you are then. If that is all that is wrong you will find out soon enough.
05-09-2018 | 02:27 PM
#6
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2012 C250 Sport
05-11-2018 | 10:00 AM
#7
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From: Philly area
350 GLK, C280
You may have a problem with the ABS pump and distribution block. How many miles. My 210 GLK, same engine, had this problem at 115,000 miles. The replacement is over $1500 at the dealer for a new system.
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05-11-2018 | 11:24 AM
#8
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2012 C250 Sport
I'm at about 77k miles now. So far I've replaced the two front wheel speed sensors and those don't seem to be the problem as all the lights are still on. Starting on the back ones now, but if nothing else so far all of this has confirmed that I need new tires ASAP. As in the front passenger side one I just took off is starting to separate on the inside edge. They look worn from the outside but not anywhere near THAT bad. So adding that to the immediate to-do list.
05-11-2018 | 02:51 PM
#9
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2012 C250 Sport
Well I've replaced all 4 ABS sensors now and was able to drive around the block with no limp mode, BUT the ABS and EBD is still showing as inoperable on the display and the check engine light is still on. Should these go off on their own once the problem is fixed or do they have to be reset?
01-07-2020 | 10:44 AM
#10
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w204
Solution
what was the solution to this?
Well I've replaced all 4 ABS sensors now and was able to drive around the block with no limp mode, BUT the ABS and EBD is still showing as inoperable on the display and the check engine light is still on. Should these go off on their own once the problem is fixed or do they have to be reset?
01-22-2020 | 02:55 PM
#11
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C250 and GLC300
I am experiencing something very similar. ABS and Traction Control lights are on. My battery was in need of replacement so we did that this morning. Now the check engine light is on as well. The guy at the shop says it is the driver side ABS sensor and he'll swap it for me for $250. After reading this post, I can't say that I want to pay a guy $250 to swap out a part and then keep paying him to swap parts if it doesn't work. I might order the part myself and do it on my own if I can find a video on it. Has anyone else done this before? I wish I knew how the OP fared after swapping all of the sensors and having the light reset.
01-22-2020 | 04:18 PM
#12
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From: Milwaukee, WI USA
2012 C300 4Matic
The guy at the shop probably used a code reader and the code was for the driver side front wheel, so more than likely he we wasn't shooting in the dark. Best way would be to have thecode(s) read and see exactly what comes up.
I would guess if you do a search on here or on the internet you could find something where you could replace it yourself. Definitely something a DIYer could do with some attention to detail.
I would guess if you do a search on here or on the internet you could find something where you could replace it yourself. Definitely something a DIYer could do with some attention to detail.
01-22-2020 | 04:24 PM
#13
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This is true. He did use a code reader to check it. I have found a couple of write ups on the swap and it doesn't look bad at all. I'm going to order two and replace both in the front. I only hope that the lights will reset themselves when the problem is gone. I bet it will because the light was off for a couple minutes this morning. Anyway, thank you for the response. I definitely feel better about doing it myself!
01-22-2020 | 04:33 PM
#14
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From: Milwaukee, WI USA
2012 C300 4Matic
I am not sure if the code would immediately go off if you replace the sensor. Might take a few drive cycles without the issue being present before it would turn off. Maybe someone here will chime in on that.
Sounds like you do not have a code reader. If not, you might consider buying one. I think it is a very cheap investment and invaluable to have. Get one that can read Mercedes codes in addition to the generic codes and also one that reads more then just the typical P (Powertarin) codes. Like the wheel speed sesnor would be a C (chassis) code. There are a number of them. I bought an icarSoft unit and it is very helpful.
Sounds like you do not have a code reader. If not, you might consider buying one. I think it is a very cheap investment and invaluable to have. Get one that can read Mercedes codes in addition to the generic codes and also one that reads more then just the typical P (Powertarin) codes. Like the wheel speed sesnor would be a C (chassis) code. There are a number of them. I bought an icarSoft unit and it is very helpful.
01-22-2020 | 04:39 PM
#15
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C250 and GLC300
I may be in luck. I just drove it up the street to get my son from the bus. The lights have reset. I am of course going to swap the sensor still but this probably means that it will reset once I do. I don't have a code reader but you're right, I'm sure I would benefit from one. I have the C250 and a newer GLC. The GLC is still under warranty so I don't work on it much yet, but I will. Thank you for the info. I'm going to research one now.
01-22-2020 | 04:54 PM
#16
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2012 C250 Sport
As it turned out, the ABS sensor part numbers for the 2012 C250 switched partway through the year, but I didn't pay any attention to this when I bought them. So while they technically worked when I replaced them all, one of the sets (either front or rear, I can't remember now) was the part number for the *other* half of 2012. I contacted the company I bought them from and they sent me the correct parts. Once I drove for a bit the ABS and check engine lights went off and everything was good to go.
01-22-2020 | 04:55 PM
#17
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2012 C250 Sport
I am not sure if the code would immediately go off if you replace the sensor. Might take a few drive cycles without the issue being present before it would turn off. Maybe someone here will chime in on that.
Sounds like you do not have a code reader. If not, you might consider buying one. I think it is a very cheap investment and invaluable to have. Get one that can read Mercedes codes in addition to the generic codes and also one that reads more then just the typical P (Powertarin) codes. Like the wheel speed sesnor would be a C (chassis) code. There are a number of them. I bought an icarSoft unit and it is very helpful.
Sounds like you do not have a code reader. If not, you might consider buying one. I think it is a very cheap investment and invaluable to have. Get one that can read Mercedes codes in addition to the generic codes and also one that reads more then just the typical P (Powertarin) codes. Like the wheel speed sesnor would be a C (chassis) code. There are a number of them. I bought an icarSoft unit and it is very helpful.
01-22-2020 | 05:04 PM
#18
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2012 C250 Sport
I am experiencing something very similar. ABS and Traction Control lights are on. My battery was in need of replacement so we did that this morning. Now the check engine light is on as well. The guy at the shop says it is the driver side ABS sensor and he'll swap it for me for $250. After reading this post, I can't say that I want to pay a guy $250 to swap out a part and then keep paying him to swap parts if it doesn't work. I might order the part myself and do it on my own if I can find a video on it. Has anyone else done this before? I wish I knew how the OP fared after swapping all of the sensors and having the light reset.
From my memory, the ABS and check engine lights went off on their own once the sensors were replaced (but if you read one of my other comments here from today, I learned that the part numbers for either the front or rear sensors (I can't remember which one now) was changed partway through 2012, so I originally ordered the wrong part number and was confused when the error codes still showed. But once I got the correct parts on everything was good to go.
01-22-2020 | 05:10 PM
#19
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C250 and GLC300
Thanks a bazillion for the update! I ordered one for each side in the front and will update after I'm finished. This one is a 2014 so I'm hoping the part numbers are true. I should be ready to rock with my new battery and sensors! I wish I had known it was going out. I would have done them with the brakes!
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frankenburied (01-22-2020)
01-25-2020 | 08:27 AM
#22
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C250 and GLC300
I'm just going to use the lug wrench in the trunk that you would use to change a flat. I would love to use an air impact, but I no longer keep those sorts of tools as I don't have the garage space here.
01-25-2020 | 09:09 AM
#24
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2012 C250 Sport
mine wouldn’t either with the little short lug wrench from the trunk. I think the shop guys overtightened the lug nuts last time I took it in. I ended up using a longer pipe that would fit over the handle part of the wrench to get more leverage and it worked
02-11-2020 | 02:16 PM
#25
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C250 and GLC300
Update:
I changed both sensors on the front and the warning lights have gone out. It was a pretty straightforward swap out. I was happy to see that there were no star bolts or anything like that. The connector is a bit of a pain to pull. Here's the link to the page I used to get a general idea for the project. in case anyone comes here later with similar questions.
I changed both sensors on the front and the warning lights have gone out. It was a pretty straightforward swap out. I was happy to see that there were no star bolts or anything like that. The connector is a bit of a pain to pull. Here's the link to the page I used to get a general idea for the project. in case anyone comes here later with similar questions.
