W212 wheel speed sensor fault after wheel bearing replacement
Thread Starter
Newbie
Joined: Jan 2014
Posts: 5
Likes: 0
From: DFW TX
W212 sedan
W212 wheel speed sensor fault after wheel bearing replacement
Hey all,
I replaced both front wheel bearings and seals on my 2011 E350 RWD sedan, but when I drove it 30 yards from the shop the BRAKE warning comes on and says there's a fault and disables the traction control and ABS systems and also my cruise control won't work. I bought the MB Carsoft scanner, and sure enough both front wheel sensors were reading erratically - good for a second, then to 0, then to half of the rear wheels, then back to the same, etc. The wheel bearings and seals were National brand, supposedly the same as OEM (BCA 32008 inner, BCA A12 outer, NAT 710588 seals.)
Thinking it was the seals, I pulled the hubs and replaced both seals with OEM parts. Still get the same erratic readings on the front right but the front left reads 0 wheel speed now.
Help would be greatly appreciated before I just start throwing more money and parts at it, I'm puzzled. The seals press in flush to the hub, the ABS/wheel speed sensor appears to be fine and undamaged. I don't know what to do next except replace the sensor or maybe order the full replacement OEM hub with the bearings and races already installed since they don't sell the OEM bearings for the E212 separately but that's like $400/side!
Thanks!
I replaced both front wheel bearings and seals on my 2011 E350 RWD sedan, but when I drove it 30 yards from the shop the BRAKE warning comes on and says there's a fault and disables the traction control and ABS systems and also my cruise control won't work. I bought the MB Carsoft scanner, and sure enough both front wheel sensors were reading erratically - good for a second, then to 0, then to half of the rear wheels, then back to the same, etc. The wheel bearings and seals were National brand, supposedly the same as OEM (BCA 32008 inner, BCA A12 outer, NAT 710588 seals.)
Thinking it was the seals, I pulled the hubs and replaced both seals with OEM parts. Still get the same erratic readings on the front right but the front left reads 0 wheel speed now.
Help would be greatly appreciated before I just start throwing more money and parts at it, I'm puzzled. The seals press in flush to the hub, the ABS/wheel speed sensor appears to be fine and undamaged. I don't know what to do next except replace the sensor or maybe order the full replacement OEM hub with the bearings and races already installed since they don't sell the OEM bearings for the E212 separately but that's like $400/side!
Thanks!
Thread Starter
Newbie
Joined: Jan 2014
Posts: 5
Likes: 0
From: DFW TX
W212 sedan
There is no vibration from the wheels. I tightened the spindle nuts today and now my scanner shows steady wheel speed at both front sensors. However, I still get the fault message saying L6/1 left front axle rpm sensor has a mechanical fault and same for the right. I'm surprised since I figured now that my scanner shows it's picking up steady wheel speeds it would work! I don't have the tool to torque them to spec and can't find a good tutorial. Now that they're reading, still think that's my problem?
Thread Starter
Newbie
Joined: Jan 2014
Posts: 5
Likes: 0
From: DFW TX
W212 sedan
Took it to a mechanic, they ordered the whole hub and bearing kit from MB and installed. That worked. Evidently you can buy just the bearings aftermarket still (same part number and everything) but they've changed specs so that's why MB only sells the hub and bearing together. I'd recommend trying the hub/bearing combo straight from MB and see if that fixes your issues.
Trending Topics
Newbie
Joined: Dec 2021
Posts: 3
Likes: 2
w212 e250 cgi
Resolved
Took it to a mechanic, they ordered the whole hub and bearing kit from MB and installed. That worked. Evidently you can buy just the bearings aftermarket still (same part number and everything) but they've changed specs so that's why MB only sells the hub and bearing together. I'd recommend trying the hub/bearing combo straight from MB and see if that fixes your issues.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Junior Member
Joined: Mar 2016
Posts: 18
Likes: 1
From: Massachusetts
2002 C32 AMG/1999 C230k
Just to put in my input on a similar situation, upon closer examination the tone ring/seal is not fully pressed into the hub. If you press it in fully it will be too far from the sensor causing the issues you are having. I had to use a screwdriver and a hammer and tap it back out slightly so it was closer to the wheel speed sensor. But I could not find an official specification on the distance it should be, but yes, also buying a new assembled hub will also have the correct distance set.
