Mercedes Wheel Speed Sensor, ABS, ESP, Check Engine Light Fix
07-04-2023, 10:49 AM
#1
Super Member
Thread Starter
Mercedes Wheel Speed Sensor, ABS, ESP, Check Engine Light Fix
I resolved wheel speed sensor problem with our 2005 W211 E500 wagon with ABS, ESP and Check Engine warnings on the dash. Short story: Replaced speed sensor and axle shaft reluctor ring with multiple related fault codes cleared with a reader.
Codes came back on the iCarsoft MB II for left rear wheel speed sensor malfunction. Of course the old plastic wheel speed sensor broke off in the hub as soon as I touched it, so I asked my Indy mechanic to drill it out while there to do the MB S.O.S. message delete (unrelated.) He drilled right past the old sensor guts into the magnetic reluctor ring and it was completely toast then. To be honest, it was rusted out and probably needed replaced anyway.
I ordered the magnetic reluctor ring to do the replacement myself. It was less than $20. Heck the speed sensor was less than $40. Fun part was getting the left rear 5 link rear suspension apart to get at the axle end where the magnetic ring is located. Not for the faint of heart but it can be done in the driveway with enough tools. TIP: I used a Dewalt heavy duty 1/2" battery impact gun with a 1-1/4" 12 point socket to get the axle nut loose. SUPER TIP OF THE DAY: use or rent a Large Hilti Drill (Hammer Drill) set to chisel only (no-spin) with a drill bit to impact the outbound center dimple of the axle shaft in to push it into the wheel hub until loosened. This is a game changer to get CV Axles loose from any hub!
Now accessible, the old reluctor ring came right off and I carefully tapped the new one on using a wooden dowel with the axle still in the car. Just make sure before you tighten up all the suspension bolts that you raise up the the loose wheel assembly to a normal ride height in the fender well so that rubber bushings get tightened at the proper ride height "resting condition" so as not to stress the rubber bushings out.
To summarize again, these two part replacements, along with fault clearing using the iCarsoft MBII reader eradicated the dash of the ABS, ESP malfunction warnings & check engine light. Since so many things are tied into the wheel speed sensor data, these related fault codes need to be cleared to turn off the check engine light too. Ah Ha, I knew something was up as soon as the wheel speed sensor & check engine light lit up all at the same time
I noticed on a euro W211 video that the 
light comes on the dash with this issue instead of the check engine light like on the US models.
Thanks
Codes came back on the iCarsoft MB II for left rear wheel speed sensor malfunction. Of course the old plastic wheel speed sensor broke off in the hub as soon as I touched it, so I asked my Indy mechanic to drill it out while there to do the MB S.O.S. message delete (unrelated.) He drilled right past the old sensor guts into the magnetic reluctor ring and it was completely toast then. To be honest, it was rusted out and probably needed replaced anyway.
I ordered the magnetic reluctor ring to do the replacement myself. It was less than $20. Heck the speed sensor was less than $40. Fun part was getting the left rear 5 link rear suspension apart to get at the axle end where the magnetic ring is located. Not for the faint of heart but it can be done in the driveway with enough tools. TIP: I used a Dewalt heavy duty 1/2" battery impact gun with a 1-1/4" 12 point socket to get the axle nut loose. SUPER TIP OF THE DAY: use or rent a Large Hilti Drill (Hammer Drill) set to chisel only (no-spin) with a drill bit to impact the outbound center dimple of the axle shaft in to push it into the wheel hub until loosened. This is a game changer to get CV Axles loose from any hub!
Now accessible, the old reluctor ring came right off and I carefully tapped the new one on using a wooden dowel with the axle still in the car. Just make sure before you tighten up all the suspension bolts that you raise up the the loose wheel assembly to a normal ride height in the fender well so that rubber bushings get tightened at the proper ride height "resting condition" so as not to stress the rubber bushings out.
To summarize again, these two part replacements, along with fault clearing using the iCarsoft MBII reader eradicated the dash of the ABS, ESP malfunction warnings & check engine light. Since so many things are tied into the wheel speed sensor data, these related fault codes need to be cleared to turn off the check engine light too. Ah Ha, I knew something was up as soon as the wheel speed sensor & check engine light lit up all at the same time
I noticed on a euro W211 video that the light comes on the dash with this issue instead of the check engine light like on the US models.Thanks
07-08-2023, 09:34 AM
#2
Super Member
Thread Starter
Sorry, posted this in the wrong spot.
Admin. Please move to W211 section. Thanks!
Admin. Please move to W211 section. Thanks!
