Wheel sensor fault - where next?

[IanMSpencer]

S204 2012 C Class Mercedes C220 Cdi Estate

I've got the usual array of ABS lights from a faulty sensor going on and using my cheapy Merc code reader confirmed it was front right. I now realise it is important that the ABS lights come on almost immediately on turning on the ignition, no movement required, and the fault code immediately is reinstated even if wiped.

In the run up to the fault I thought there were two possibilities: kerbing the wheel causing a puncture, which was front left, and some over enthusiastic water spraying under wheel arches during car washing, together with being suspicious of flat battery due to lack of use.

Anyway, decided to get a (Bosch) wheel sensor and changed that and the fault remains. Checking the old sensor, it seems to give a sensible infinite resistance reading on a multimeter.

Doing further diagnostics, the live data shows that there is no speed signal coming from front right, the other wheels showing sensible numbers.

I think I can eliminate the ring in the hub as that would not cause the readings.

Where next? Any relays to swap around?

 

[Mondayo]

Hi Ian,

Did you get any further with working out what was wrong?

I'm getting similar error messages and so took my car tot the garage. There seemed to be a problem with a wheel speed sensor and so that got changed and now at least the car can see the sensor...but it's still throwing up the error and I'm getting multiple error messages.

Mine is a 2004 E55 S211.

 

[IanMSpencer]

Hi Ian,

Did you get any further with working out what was wrong?

I'm getting similar error messages and so took my car tot the garage. There seemed to be a problem with a wheel speed sensor and so that got changed and now at least the car can see the sensor...but it's still throwing up the error and I'm getting multiple error messages.

Mine is a 2004 E55 S211.

I missed a step or two, and was going to swap left and right sensors to see if I'd fitted a faulty replacement, and also use a multimeter to check the voltage to the sensor.

There didn't seem to be any obvious other relays when I checked the wiring.

Basically, it got too hot to be bothered! Now it's too wet! So still a work in progress.

 

[AMV]

In the process of changing mine.

My ABS sensor is stuck on at ignition which i believe to be because i have fitted an incorrect part.

I've managed to get a hold of the OEM part from Merc which was on back order. Hoping to fit tomorrow and hopefully this saga will be over..

 

[Mondayo]

Sounds like we're going down similar routes then.

Took my car to an auto electrician who confirmed he thinks its a sensor on the rear drivers side....but still slightly in the dark to what it actually is. I spoke to my normal garage this morning and now they're saying it was an ABS sensor they changed, not a speed one!?!

It's going to a mates garage on Friday and the auto electrician and mechanic will look at it together and hopefully get to the bottom of it. Getting a bit bored of the PAS going into limp mode.

 

[AMV]

ABS Sensor is a Wheel speed sensor or also known as an RPM Sensor. (To my knowledge)

 

[AMV]

I managed to change mine and all is well! Touch wood.

A OBD scanner should be able to tell them which sensor is faulty.

I noticed when doing a diagnostic of the wheel speed sensors that the power steering gets turned off. I just restarted the car and it worked again. The diag test is to check the new sensor is working.

 

[wongl]

Sounds like we're going down similar routes then.

Took my car to an auto electrician who confirmed he thinks its a sensor on the rear drivers side....but still slightly in the dark to what it actually is. I spoke to my normal garage this morning and now they're saying it was an ABS sensor they changed, not a speed one!?!

It's going to a mates garage on Friday and the auto electrician and mechanic will look at it together and hopefully get to the bottom of it. Getting a bit bored of the PAS going into limp mode.

Any update on this?

 

[Mondayo]

Any update on this?

Sorry, got distracted.

I got another speed/ABS sensor, but a proper part, not a cheapo pattern one (think it was something like £25-30 for pattern part and £45ish for the proper part). Anyway took them 30 minutes to fit it, test it and clear codes and fingers crossed it fixed the problem!

To be clear, this is just the cabling sensor that was changed.

I've now got an intermittent ride height issue but I don't think that's related

 

[bob6600]

It has been mentioned before that using even branded parts like Bosch have caused issues on Mercs, always go for an original part. If it persists, it could be the pick up/reluctor ring. Worse case scenario, the ABS controller.

 

[Mondayo]

It has been mentioned before that using even branded parts like Bosch have caused issues on Mercs, always go for an original part. If it persists, it could be the pick up/reluctor ring. Worse case scenario, the ABS controller.

Yes, the pick ring has been mentioned.

 

[Wolfie1]

If it was the ring you would expect the code to clear and then light come back on again when you drive again, saying that anything is possible

 

[Rbfive]

S204 2012 C Class Mercedes C220 Cdi Estate

I've got the usual array of ABS lights from a faulty sensor going on and using my cheapy Merc code reader confirmed it was front right. I now realise it is important that the ABS lights come on almost immediately on turning on the ignition, no movement required, and the fault code immediately is reinstated even if wiped.

In the run up to the fault I thought there were two possibilities: kerbing the wheel causing a puncture, which was front left, and some over enthusiastic water spraying under wheel arches during car washing, together with being suspicious of flat battery due to lack of use.

Anyway, decided to get a (Bosch) wheel sensor and changed that and the fault remains. Checking the old sensor, it seems to give a sensible infinite resistance reading on a multimeter.

Doing further diagnostics, the live data shows that there is no speed signal coming from front right, the other wheels showing sensible numbers.

I think I can eliminate the ring in the hub as that would not cause the readings.

Where next? Any relays to swap around?

Hello sir, did you ever resolve your issue with the speed sensor not reading? I am having the same issues.
Thanks you

 

[IanMSpencer]

I ended up with it sitting on the drive in lockdown, then taking it to a garage who replaced the sensor again and it worked fine so it was either something with my installation or these sensors are trouble! As there were no additional parts, it has to be one or the other! No problems since.

 

[Bill2411]

S204 2012 C Class Mercedes C220 Cdi Estate

I've got the usual array of ABS lights from a faulty sensor going on and using my cheapy Merc code reader confirmed it was front right. I now realise it is important that the ABS lights come on almost immediately on turning on the ignition, no movement required, and the fault code immediately is reinstated even if wiped.

In the run up to the fault I thought there were two possibilities: kerbing the wheel causing a puncture, which was front left, and some over enthusiastic water spraying under wheel arches during car washing, together with being suspicious of flat battery due to lack of use.

Anyway, decided to get a (Bosch) wheel sensor and changed that and the fault remains. Checking the old sensor, it seems to give a sensible infinite resistance reading on a multimeter.

Doing further diagnostics, the live data shows that there is no speed signal coming from front right, the other wheels showing sensible numbers.

I think I can eliminate the ring in the hub as that would not cause the readings.

Where next? Any relays to swap around?

I had same issue and fitted a replacement from a supplier but kept throwing a fault. Then I fitted a Merc sensor which cured the fault

 

[Gazwould]

It has been mentioned before that using even branded parts like Bosch have caused issues on Mercs, always go for an original part. If it persists, it could be the pick up/reluctor ring. Worse case scenario, the ABS controller.

What about Ate ?

 

[bob6600]

What about Ate ?

I don't know who is the OEM for them but a respected Indy (might have been Steve@avantguard can't remember) who has seen this issue a lot recommended using MB parts as he has had issues with with aftermarket parts, even branded ones like Bosch.

 

[Gazwould]

Ate is the OEM for Mercedes .

 

[bob6600]

In that case, I would use it. Most big branded manufacturers (Bosch, Febi etc) are very good for aftermarket parts but for these wheel sensors there has been problems, not sure why.