This happened Thursday evening around 5pm. I was going to pick up Ian from a friend's house on probably the hottest day of the year or close to it. Started it, went windows down and sunroof open (so no A/C), and was on my way. I was only a few minutes from home when I saw the first symptom: blind spot monitor disabled or whatever on the cluster. The mirror lights went amber. Kinda weird. Eventually I got to the end of 102 and realized I had no turn signals. I couldn't really find anything else. Hazards worked fine.
Got to my destination and scanned with the Launch.
These were the current codes relating to this issue and their originating module:
Steering column module: B178F, turn signal malfunction.
Left headlamp: U0212, comms error talking to steering column module
And then here were the stored codes relating to this issue and their originating module:
Outer left rear radar sensor module: U0212, comms error talking to the steering column module
Outer right rear radar sensor module: U0212, comms error talking to the steering column module
Ok this is probably direction. I shut the car off and started it just to see if it would clear. It did not. So I began to drive home.
What I noticed is that the car slowly healed itself over the course of the 20 minute drive. First indication was the turn signals slowly started working again. Then I think eventually I had no blind spot monitor issue.
I tried Copilot for advice. It said to lower the bottom half of the column cover and unplug, inspect and replug the steering column module. That turns out was useless direction.
Scanned and did some diagnostics with Xentry in my garage. As expected, all the current faults turned to history faults as nothing was malfunctioning. Every test having to do with the SCM passed.
Same thing as a PDF:
Full scan:
Basically all signs point to the SCM.
What I did find was a thread at MB World: https://mbworld.org/forums/e-class-w212 ... issue.html
The direction I got from this is that the, I think, main harness pins for the SCM are solderless pressed into the board. This is a Mercedes thing on some of the more recent vehicle modules. And over time the connections get crappy, put junk into the network and eventually can trigger comms codes. The fix is to basically solder the pins. I am guessing this is the proper way to repair mine.
The SCM isn't a module per se, it is the entire middle stalk area on the column (with the turn signal and other stuff integrated). Removal of that requires removal of the steering wheel. But honestly this doesn't look too hard. So my options are either to just go for it, or wait until it gets worse. I do think the issue was exacerbated by the very high temps, and going from my cool garage to outside (with no A/C).
14 E63S: blind spot monitor disabled, no turn signals
14 E63S: blind spot monitor disabled, no turn signals
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Re: 14 E63S: blind spot monitor disabled, no turn signals
If I am reading ASRA correctly it might be 2 hours of book time for this repair, not counting taking the SCM apart to solder the pins. I don't have a steering wheel puller although this is not always necessary.
Here are the nested work instructions.
Forum says a T20 screw driver fits perfectly in the airbag slots to unclip it.
Added a fourth instruction for the aux battery that I think I have due to start/stop code B03. Should be in trunk.
Here are the nested work instructions.
Forum says a T20 screw driver fits perfectly in the airbag slots to unclip it.
Added a fourth instruction for the aux battery that I think I have due to start/stop code B03. Should be in trunk.
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Re: 14 E63S: blind spot monitor disabled, no turn signals
Would need part 10 (multi function switch assembly) and 904 (harness plug lock, one time use).
Switch assembly is A2129006815 9051. Not sure on the lock piece. There are like four listed. Two are called out as "lock" I guess. Maybe A0008230245?
Anyway the switch is backordered/not available on my local dealer site.
https://www.mercedesbenzpartsshop.com/o ... 0009209051
It will probably be on the order of $500 or even more if I can even get one. So I feel compelled to try repairing mine. I should probably get some locks on hand before I start.
They even have 4 in stock (that definitely is a sign that this is a common issue): https://www.mercedesbenzpartsshop.com/o ... -823024564
Ordered two at $5 total.
Switch assembly is A2129006815 9051. Not sure on the lock piece. There are like four listed. Two are called out as "lock" I guess. Maybe A0008230245?
Anyway the switch is backordered/not available on my local dealer site.
https://www.mercedesbenzpartsshop.com/o ... 0009209051
It will probably be on the order of $500 or even more if I can even get one. So I feel compelled to try repairing mine. I should probably get some locks on hand before I start.
They even have 4 in stock (that definitely is a sign that this is a common issue): https://www.mercedesbenzpartsshop.com/o ... -823024564
Ordered two at $5 total.
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Re: 14 E63S: blind spot monitor disabled, no turn signals
Honestly the biggest struggle was figuring out the cheat code to release the airbag clips.
After releasing the airbag spring clips by inserting the T20 (just to press on the spring clips not to turn anything), the airbag pops right off and then you just unplug the connector and pull that out. Steering wheel bolt takes a 10 mm Allen head. It has thread lock and takes some Force but I was able to do it by myself without somebody holding the wheel for me. Once that's loose just unplug the other plug and the wheel comes right off the column. The steering column is splined and it looks like you can easily put the wheel on the wrong way but the turn signal module, which integrates all of the stalks plus the clock spring, has an arrow that points straight up to at least show where straight ahead is. I put a piece of electrical tape on the clock spring to prevent it from turning.
With the wheel out of the way, I had to unclip the column cover boot thing from the turn signal module plastic which was just a little careful prying in four places and then it pops right off.
The final challenge was that I couldn't pull the module all the way off the steering column because the wiring harness wouldn't let it. So I looked in there and it looked like the final step was to unclip the harness plug from the back side but in order to do that I had to break the one time use lock from the plug with needle nose. Then I was able to release the clip with needle nose and it unplugged easily.
So I did order a couple of those locking pieces. But my next challenge is if I have the confidence to disassemble the module and reflow solder to the main harness pins (and not break anything).
After releasing the airbag spring clips by inserting the T20 (just to press on the spring clips not to turn anything), the airbag pops right off and then you just unplug the connector and pull that out. Steering wheel bolt takes a 10 mm Allen head. It has thread lock and takes some Force but I was able to do it by myself without somebody holding the wheel for me. Once that's loose just unplug the other plug and the wheel comes right off the column. The steering column is splined and it looks like you can easily put the wheel on the wrong way but the turn signal module, which integrates all of the stalks plus the clock spring, has an arrow that points straight up to at least show where straight ahead is. I put a piece of electrical tape on the clock spring to prevent it from turning.
With the wheel out of the way, I had to unclip the column cover boot thing from the turn signal module plastic which was just a little careful prying in four places and then it pops right off.
The final challenge was that I couldn't pull the module all the way off the steering column because the wiring harness wouldn't let it. So I looked in there and it looked like the final step was to unclip the harness plug from the back side but in order to do that I had to break the one time use lock from the plug with needle nose. Then I was able to release the clip with needle nose and it unplugged easily.
So I did order a couple of those locking pieces. But my next challenge is if I have the confidence to disassemble the module and reflow solder to the main harness pins (and not break anything).
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Re: 14 E63S: blind spot monitor disabled, no turn signals
Well I worked up the confidence.
First I removed the clamshell with my handy plastic prybar that has been working wonders for me lately (it was an O'Reilly's impulse buy). This is what the clock spring looks like. Kinda cool. Looks like it maintains a constant bend radius as the wheel rotates. Next I went around and released all the clips to pull the clock spring off of the assembly. Didn't really look like there was anything to solder on those four pins but these six I think would need soldering to the PCB. If I can access them. And here we are. Clearly pressed and not soldered. Also notice the fancy optical encoder for the steering wheel position sensor. My mission should I choose to accept it. Here we go. Firing up the TS101. Oh, before this I sprayed with Deoxit, then contact cleaner to rinse and applied liquid flux to each pin. Then I still used flux core solder. Had to touch up the last one a couple times and it looks a little wierd.
Reassembly was just clipping things together and making sure basic alignment was maintained. Pretty easy job all things considered. Added some brake parts silicone to the threads of the column tilt shaft. Now I just need the new plug lock to finish the job.
First I removed the clamshell with my handy plastic prybar that has been working wonders for me lately (it was an O'Reilly's impulse buy). This is what the clock spring looks like. Kinda cool. Looks like it maintains a constant bend radius as the wheel rotates. Next I went around and released all the clips to pull the clock spring off of the assembly. Didn't really look like there was anything to solder on those four pins but these six I think would need soldering to the PCB. If I can access them. And here we are. Clearly pressed and not soldered. Also notice the fancy optical encoder for the steering wheel position sensor. My mission should I choose to accept it. Here we go. Firing up the TS101. Oh, before this I sprayed with Deoxit, then contact cleaner to rinse and applied liquid flux to each pin. Then I still used flux core solder. Had to touch up the last one a couple times and it looks a little wierd.
Reassembly was just clipping things together and making sure basic alignment was maintained. Pretty easy job all things considered. Added some brake parts silicone to the threads of the column tilt shaft. Now I just need the new plug lock to finish the job.
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Re: 14 E63S: blind spot monitor disabled, no turn signals
The locks I ordered are in. Hopefully I picked the right one because I got two....
Re: 14 E63S: blind spot monitor disabled, no turn signals
I guess the part is back ordered and he said $680 retail. So I have an incentive to fix.
Re: 14 E63S: blind spot monitor disabled, no turn signals
Success. I mean it passed these tests before I fixed it but at least I didn't break anything. Only thing I can do now is drive it and see if it ever happens again. I will say the stupid harness plug lock fought me for what must have been an hour just to clip it into place. I started to break one and had to resort to the second one. The issue is you can't pull the unit off of the steering column while plugging it in so there is only a small place through which to shove your hand or a tool. If I was able to free up the flex cover that covers the column when it moves and bring that out, I could plug in and deal with the lock with a lot more space. But I guess I didn't feel like looking into that. I don't know if the knee panel just comes off easily. If there is a next time, I will be looking into that.
After reconnecting the battery
And after clearing codes.
After reconnecting the battery
And after clearing codes.
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Re: 14 E63S: blind spot monitor disabled, no turn signals
Just in case this helps if I have trouble in the future: https://youtu.be/OfU74lzAuHI?is=0MjRhau3S64nAkaJ
Russian guy taking apart a unit. Not sure if it's a Kostal or Valeo though.
Russian guy taking apart a unit. Not sure if it's a Kostal or Valeo though.