ABS SBC Connector Pin-out
10-10-2017, 06:52 AM
#1
Junior Member
Thread Starter
ABS SBC Connector Pin-out
Hi All,
I hope I have come to the right place to get some much needed assistance on my E320 CDI. I have an ABS dash light. I used my Carsoft MB Scanner and had a code for the Right Rear Wheel Speed Sensor.
Simple enough, I order one and install it on the car, hopped in for a drive and I still have the "ABS" dash light. I used the code scanner to try to reset the light but the light remained. Same code: RIGHT REAR WHEEL SPEED SENSOR.
Suspecting I bought a faulty Wheel Speed Sensor from EBAY, I went to my local Mercedes Benz Dealer and bought a Wheel Speed Sensor from the DEALER. I installed the new MB part and hopped in for a drive once again. I still have the "ABS" dash light. Again, I tried to reset the code but the code remained. RIGHT REAR WHEEL SPEED SENSOR.
Again, I hoped for the best and assumed that the part I purchased from Mercedes was a faulty wire, so I used the "known good" wire from the Rear Left Wheel and swapped it to the Rear Right Wheel. And again, I was looking at 2 codes, one for the left wheel (because I removed the sensor) and the other code was for the RIGHT REAR WHEEL SPEED SENSOR.
Being optimistic, I returned the Wheel Speed sensor back to the Left Rear Wheel and taped up the right rear connector to keep debris out of it. I checked the codes, one last time, and still have a code for the right wheel, obviously, and now a code for the LEFT REAR WHEEL SPEED SENSOR.
Somewhere between the right rear wheel speed sensor connector in the wheel well and the ABS/SBC pump under the hood, there is a problem. Something is shorting the connector causing it to damage the Wheel Speed Sensor.
I come to the Forum to ask a few questions:
1) Has anyone ever had this problem before? and if so what was the remedy?
2) Can any one on here provide me with a wiring schematic or pin out between the ABS/SBC connector and the Wheel speed sensors?
3) Considering a possible ABS/SBC fault, can any one recommend a good repair company that can fix my unit?
I hope I have come to the right place to get some much needed assistance on my E320 CDI. I have an ABS dash light. I used my Carsoft MB Scanner and had a code for the Right Rear Wheel Speed Sensor.
Simple enough, I order one and install it on the car, hopped in for a drive and I still have the "ABS" dash light. I used the code scanner to try to reset the light but the light remained. Same code: RIGHT REAR WHEEL SPEED SENSOR.
Suspecting I bought a faulty Wheel Speed Sensor from EBAY, I went to my local Mercedes Benz Dealer and bought a Wheel Speed Sensor from the DEALER. I installed the new MB part and hopped in for a drive once again. I still have the "ABS" dash light. Again, I tried to reset the code but the code remained. RIGHT REAR WHEEL SPEED SENSOR.
Again, I hoped for the best and assumed that the part I purchased from Mercedes was a faulty wire, so I used the "known good" wire from the Rear Left Wheel and swapped it to the Rear Right Wheel. And again, I was looking at 2 codes, one for the left wheel (because I removed the sensor) and the other code was for the RIGHT REAR WHEEL SPEED SENSOR.
Being optimistic, I returned the Wheel Speed sensor back to the Left Rear Wheel and taped up the right rear connector to keep debris out of it. I checked the codes, one last time, and still have a code for the right wheel, obviously, and now a code for the LEFT REAR WHEEL SPEED SENSOR.
Somewhere between the right rear wheel speed sensor connector in the wheel well and the ABS/SBC pump under the hood, there is a problem. Something is shorting the connector causing it to damage the Wheel Speed Sensor.
I come to the Forum to ask a few questions:
1) Has anyone ever had this problem before? and if so what was the remedy?
2) Can any one on here provide me with a wiring schematic or pin out between the ABS/SBC connector and the Wheel speed sensors?
3) Considering a possible ABS/SBC fault, can any one recommend a good repair company that can fix my unit?
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Tony Smith (05-01-2021)
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KeithParsons (08-19-2022)
08-19-2022, 06:49 AM
#6
Junior Member
Thread Starter
Reluctor Ring
Good morning Randomguys,
The issue on my car was the reluctor ring.
What that is, is a ring that fits on the rear drive shaft that counts a "pulse" for the wheel speed sensor so the ABS (sbc) is aware of the speed each wheel is turning.
I went through several wheel speed sensors, HOPING it woukd be the answer.
I even changed the reluctor ring with an EBAY part, and it didn't fix the issue. (Bad part). 20 dollars.
I ended up taking the car to MB to have them try to figure it out and hoped it would be a free fix due to a factory recall on the ABS system.
MB Dealer called me after having the car for a day and said reluctor ring on driveshaft. I told them it had been replaced. They said it wasnt outing anything for the wheel speed sensor to read.
This wasn't covered under the recall and I paid for the repair out of pocket. I think it was around 800 dollars. MB part was also like 20 dollars.
The job isn't too bad, but requires the wheel, control arms, brake disc, and wheel hub to be removed. I woukd think an independent shop would be close to half the cost of the MB dealership, or a knowledgeable back yard mechanic with a floor jack, stands, and a few metric wrenches could knock the job out under 3 or 4 hours max.
If searching how to do it, search "replacing the wheel hub", or "replacing rear cv shaft". You'll find more on that than reluctor ring. Once the wheel hub is removed, the ring is right on the end of the cv shaft. When I replaced mine with the ebay part, my original ring appeared rusty and "looked" bad, so you might see that yours appears the same way. These parts are exposed to the elements, so it seems it wouldn't be too uncommon for this to be an issue.
Good luck with your car, hope this helps. Btw...my car had 160k miles when it happened, it now has 280k miles and still runs like a diesel should!
The issue on my car was the reluctor ring.
What that is, is a ring that fits on the rear drive shaft that counts a "pulse" for the wheel speed sensor so the ABS (sbc) is aware of the speed each wheel is turning.
I went through several wheel speed sensors, HOPING it woukd be the answer.
I even changed the reluctor ring with an EBAY part, and it didn't fix the issue. (Bad part). 20 dollars.
I ended up taking the car to MB to have them try to figure it out and hoped it would be a free fix due to a factory recall on the ABS system.
MB Dealer called me after having the car for a day and said reluctor ring on driveshaft. I told them it had been replaced. They said it wasnt outing anything for the wheel speed sensor to read.
This wasn't covered under the recall and I paid for the repair out of pocket. I think it was around 800 dollars. MB part was also like 20 dollars.
The job isn't too bad, but requires the wheel, control arms, brake disc, and wheel hub to be removed. I woukd think an independent shop would be close to half the cost of the MB dealership, or a knowledgeable back yard mechanic with a floor jack, stands, and a few metric wrenches could knock the job out under 3 or 4 hours max.
If searching how to do it, search "replacing the wheel hub", or "replacing rear cv shaft". You'll find more on that than reluctor ring. Once the wheel hub is removed, the ring is right on the end of the cv shaft. When I replaced mine with the ebay part, my original ring appeared rusty and "looked" bad, so you might see that yours appears the same way. These parts are exposed to the elements, so it seems it wouldn't be too uncommon for this to be an issue.
Good luck with your car, hope this helps. Btw...my car had 160k miles when it happened, it now has 280k miles and still runs like a diesel should!
08-21-2022, 06:27 PM
#7
Ditto on reluctor ring. As my indie explained it, even though the code says wheel sensor, that doesn't rule out the possibility that it could be the reluctor ring. So you almost have to replace the speed sensor to see where you stand.
