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*FIXED* Blind Spot Assist Inoperative - Journey to fixing it
*FIXED, solution detailed through thread*
Hi all,
just wanted to document how I am going about trying to fix this issue. When I start the truck, it gives me the message blind spot assist and lane assist inoperative messages. I just “OK” them through and continue on my way. Well today I was finally able to get both sensors out. I tried a couple times before but gave up.
To get the sensors out, just bend the heatshield to give you room to work. Unplug the cable from the sensor by pressing down on the top/bottom tabs and wiggle it out. I am at 67k so they were hard especially over the years of built up salt/grime/dirt.
Once the connector is unplugged, it slides horizontally out the other end of the sensor, but there is a tab on the opposite side to where the connector is (not the tab on that is clearly visible). Lift the tab and push/slide the sensor out.
From there, take a thin flat head and pry the sensor apart. Go slow and pry about 3 spots per side to get the cracking of it to get it open.
Once it is apart then start inspecting and cleaning with isopropyl alcohol and q-tips and an old toothbrush.
You can see in my pictures where the water penetrated badly on one sensor. The other sensor looks clean.
Unfortunately, the worst conditioned one I took a blade to cut the plastic holders off and on one the blade crashed into the microchip. Unbelievable! Three pins were damaged, one of them looks to be on a power plane, but this one was probably already damaged to begin with. I will put these back together temporarily and test it out. Maybe unplugging and plugging them back in fixes the issue.
In the meantime, I ordered a genuine replacement sensor on ebay for $115, so I will report back here as I get closer to hopefully fixing this!
Last edited by Gray_Panther; 06-07-2023 at 08:32 PM.
Reason: solution found
great tips and pics, thank you. I'm also looking to do mine at some point. I've noticed sometimes (rarely) the turn signals also won't work, and i believe it is related to the blind spot sensor inoperative error.
Any concern with there being an issue with the harness/did you inspect it?
i was going to replace the sensors but was also thinking of replacing the harness, would hate to do all that work and still run into a problem due to a harness issue/water damage in the harness.
Rock Auto hasnt had the sensor in stock for quite some time, please follow up once you finish and if your ebay sensor worked out i may also purchase from ebay.
great tips and pics, thank you. I'm also looking to do mine at some point. I've noticed sometimes (rarely) the turn signals also won't work, and i believe it is related to the blind spot sensor inoperative error.
Any concern with there being an issue with the harness/did you inspect it?
i was going to replace the sensors but was also thinking of replacing the harness, would hate to do all that work and still run into a problem due to a harness issue/water damage in the harness.
Rock Auto hasnt had the sensor in stock for quite some time, please follow up once you finish and if your ebay sensor worked out i may also purchase from ebay.
The harness looked just fine, If you are concerned with the harness see if you can run a beep test before having the harness replaced because that can be labor intensive. Replacing the connector is easy but the harness will definitely take time to do.
Originally Posted by BlownV8
Please post the part number if you have it on hand. Also, do you know if this a part that needs to be coded to the car?
I have no clue if it needs to be reprogrammed, but the part number is as follows:
A 000 905 06 10
Autoliv P/N 6221569 08A
SW: A 000 902 54 05
HW: A 000901 30 01
I will be installing back onto the truck tomorrow and will see if the system is still inoperative after cleaning the circuit board and damaging the one microprocessor chip
Bought a sensor on Ebay and based on my research, once you buy a sensor with all the same details: Part #, SW and HW it would work. I know in my case the part number is different than what @Gray_Panther has.
Well I plugged them back in and no change. But I only left the car running for a minute. My woman is taking it for a drive to work later so maybe it goes away on its own. But I suspect that module I damaged is the offender and when I get my replacement in the mail I will swap it in and see if it fixes it.
If it does fix it then I will seal the connector up with dielectric grease and silicone around the module so water doesn’t seep in again.
Well I plugged them back in and no change. But I only left the car running for a minute. My woman is taking it for a drive to work later so maybe it goes away on its own. But I suspect that module I damaged is the offender and when I get my replacement in the mail I will swap it in and see if it fixes it.
If it does fix it then I will seal the connector up with dielectric grease and silicone around the module so water doesn’t seep in again.
I'd run a OBD scan and clear the codes first, then see if the error pops back up. If it does run a scan again and it should specify which sensor left or right is causing the code.
Still not solved but I think I am getting closer. When I tried swapping in the replacement unit the issue still persisted and I tried the combinations hoping to eliminate one of the modules. But no luck.
So I drove to my godfather’s garage to see what his scanner can pick up and i got the following messages:
So now I think I should look at replacing the distronic module since the radar modules aren’t even communicating with it.
I got the front distronic module out!
I had to remove the front grill and rip out the foam that sits on top of the passenger side distronic module to access the clips to remove the flap.
There is a second slot on the driver side that is empty, I am assuming that is for the distronic+.
Next step is ordering a replacement module and see if that is that the solution. If it isn’t then I won’t know what to do next.
Well bad news. The used modules I picked up from eBay do not work, and I will be returning them and getting my money back.
Unfortunately, this has to be put on pause until end of next year as I don't want to spend that kind of money considering I have multiple close family weddings next year. For now, I am going to keep the modules off the car, squeeze dielectric grease in the connectors and plug them up so that water doesn't seep in.
Here is some resources to assist when you look to re-attempt. I did a search in WIS for Module A89 and found the attachments.
This will confirm the location of module A89 (behind grill emblem), see page 8 (its illustrated diagram and then list of component names below the diagram). the 2nd attachment provides details about the A89 Module and the function.
As ml3504matic mentioned, could it have been that the unit you ordered may have been defective. I'm not sure if there is any type of programming needed on these distronic units specifically versus the blind spot sensors which did not need any programming.
UPDATE:
Beautiful day for Memorial day today, keep those who have departed in memory!
I had some spare time and my father and I got to work troubleshooting. I will take pictures next time I am under the truck and will write a detailed report for those to use in the future.
We started by disconnecting the connectors from both modules and checking to see voltages on the four pins. Ground pin had good continuity to the muffler, so we know ground is connected. We saw voltages on the two data (green) pins so we knew the computer is sending signals to those pins. We didn't see any voltage on the positive pin. Next logical step was the disconnect the wiring harness from the breakout connector (pictures to come at a later date, but feel free to message me for a better description) and see if we saw the same thing, which of course we did.
Fuse location 116. Sure enough it was blown so we replaced it. Once that was done we set the key to the position for electronics and started getting power back on the power pins. Took the key out, connected back up the original modules, and turned the car back on and still got the Blind Spot Assist Inoperative message.
Next step is to get those modules replaced. I feel like I am really close!
UPDATE:
Beautiful day for Memorial day today, keep those who have departed in memory!
I had some spare time and my father and I got to work troubleshooting. I will take pictures next time I am under the truck and will write a detailed report for those to use in the future.
We started by disconnecting the connectors from both modules and checking to see voltages on the four pins. Ground pin had good continuity to the muffler, so we know ground is connected. We saw voltages on the two data (green) pins so we knew the computer is sending signals to those pins. We didn't see any voltage on the positive pin. Next logical step was the disconnect the wiring harness from the breakout connector (pictures to come at a later date, but feel free to message me for a better description) and see if we saw the same thing, which of course we did.
Fuse location 116. Sure enough it was blown so we replaced it. Once that was done we set the key to the position for electronics and started getting power back on the power pins. Took the key out, connected back up the original modules, and turned the car back on and still got the Blind Spot Assist Inoperative message.
Next step is to get those modules replaced. I feel like I am really close!
I have the very same problem on my 2013 ML350 4matic
fusea are all good… I put new sensors and connected ecu to xentry and the complaints is no communication to sensors. I am going to check voltage on connectors. If that comes good, not sure what else
I have the very same problem on my 2013 ML350 4matic
fusea are all good… I put new sensors and connected ecu to xentry and the complaints is no communication to sensors. I am going to check voltage on connectors. If that comes good, not sure what else
did you scan it with Xentry and the engine ON? I always get bljnd spot codes when I use Xentry with engine OFF and key position 2.
I snagged a used replacement module off of ebay and replaced the module that was most oxidized, which also happened to be the one where I damaged 3 pins on the microprocessor.
No fuse blown, and everything is working again with no error messages. The car even beeped when someone was driving past my wife when she initiated the turn signal to change lanes on the highway. Very happy the truck is fully functional again.
I will remove the fuse and then both modules again tonight so I can put dielectric grease on the connections and 100% silicone around the seam of the modules to prevent water ingress. Install back up tomorrow and forget about it!
I will take pictures and give a bit more detail when I have some free time to do so.
Noted, except my one module was opened by me so I have to reseal. In my search another person(s) found that their leak came from the sides, not just the connectors.
Will fill with dielectric grease on connectors to prevent moisture from getting in.
I snagged a used replacement module off of ebay and replaced the module that was most oxidized, which also happened to be the one where I damaged 3 pins on the microprocessor.
No fuse blown, and everything is working again with no error messages. The car even beeped when someone was driving past my wife when she initiated the turn signal to change lanes on the highway. Very happy the truck is fully functional again.
I will remove the fuse and then both modules again tonight so I can put dielectric grease on the connections and 100% silicone around the seam of the modules to prevent water ingress. Install back up tomorrow and forget about it!
I will take pictures and give a bit more detail when I have some free time to do so.
Another Blind Spot sensor issue - connector loose inside
My 2013 ML350 sensor worked sporadically. I thought it must be dirty. Each time I stuck the power washer into the area with the sensor and blasted it to clean it, it started working again. I got tired after doing this three times in a year. Took it out and carefully disassembled.
The connector in the sensor is pressed into the circuit board. In my case, the connector was not properly pressed into the circuit board. I pressed it in and then soldered it. Put it back together with some sealer. Much better now.
Turns out the violent vibration from the power washer was shaking it enough to make the connection work again.
My 2013 ML350 sensor worked sporadically. I thought it must be dirty. Each time I stuck the power washer into the area with the sensor and blasted it to clean it, it started working again. I got tired after doing this three times in a year. Took it out and carefully disassembled.
The connector in the sensor is pressed into the circuit board. In my case, the connector was not properly pressed into the circuit board. I pressed it in and then soldered it. Put it back together with some sealer. Much better now.
Turns out the violent vibration from the power washer was shaking it enough to make the connection work again.
You experienced the "pressed pins" issue. These "pressed pins" are all over the vehicle including ignition module (key), steering control module (tranny shifter), ISM (tranny actuator), etc.
here is a bible for electrical issues common to many MB, but described on the W212 platform (the sedan version of the W166 in my opinion). Enjoy, I am sure you will appreciate it ( https://mbworld.org/forums/e-class-w...ml#post8757496)
I have problems with my rear right blind spot sensor of 2013 W212. A diagnostic showed a water damage.
Maybe it is possible to repair it. But one part was destroyed because of high temperature. The part number can not be seen. So i need a high quality foto of this part. I think on your original fotos it is possible to see the part number.
10-21-2022, 04:12 PM
