R230 SL500 ESP / ABS / BAS/ Speedtronic / Service brake fault

[Oilman471]

Hi everyone I am new to the group and looking for some help.

I have searched the forums and internet no end on this issue and wondered if anyone had any ideas.

I have had this issue on and off for about 2 years although it would reset with switching off and back on and not reappear for months. It gradually got worse and the errors would come up pretty much everytime I drove the car, sometimes almost straight away other times after an hour.

I have an MBv2 Icarsoft scanner and Wurth scanner and both have come up with NSR wheel speed sensor. I have changed the sensor to an aftermarket one and also have fitted a new reluctor ring from Reluctor rings . com the sensor was seized and had to be drilled out. This initially fixed the issue as the lights were coming on when I started the car and now come on after approx 15 mins of driving.

I ordered a genuine Wheel speed sensor which I got the other day and after fitting it the car would throw all the above faults within 50 metres or so. i have put the aftermarket one back on and it faults after about 15 mins.

I have checked the Can bus connections in the passenger footwell they are dry but the brown set of canbus connectors look like they have been repaired at some time as they have heatshrink wrap on them and the 2 buz bars one is a little discoloured. I have disconnected both the green and brown can bus connectors in the passenger footwell and cleaned them 1 by 1 with switch cleaner. The brake pedal switch was changed a while ago.

When i removed the genuine speed sensor it was difficult to get it out of the electrical plug that it goes in and then difficult to get the aftermarket one back in to.

I also have an issue with the multi contour seats air system not working. If I connect an airline to the pipe that attaches to the PSE pump in the boot they work fine. PSE works fine other wise it seems the seats don't "call the pump to operate" this may be related to the speed sensor?

Help and ideas welcomed.

 

[LostKiwi]

Seat problem will not be related and is probably a leaking hose. Your MB2 should see an error. If an error is present the pump won't operate that air circuit and you'll need to clear the codes.

The ABS sensor sounds like it's not getting a good signal off the reluctor. Check using live data what the speed reported is by the sensor compared to other sensors. Check the sensor gap - if it's too wide the readings will be erratic.

 

[Oilman471]

Thanks for the quick reply.

Live data shows the wheel speeds all being almost the same. It does seem strange that one sensor picks up the reluctor for a period and the other wont.

How do I check the sensor gap by removing wheel and using feeler gauges between the sensor and ring? Do you know what should it be?

 

[LostKiwi]

Should be around 1.0mm

 

[Oilman471]

Hi I have tried to check the gap but i cannot get any feeler gauges in the hub to check as there doesn't seem to be any room. Will see if i can remove the sensor and check the depth and then measure the depth of the sensor.

 

[Oilman471]

Car is in the garage today to see if they can work out what the issue is.

 

[Oilman471]

Issue has now been solved. The new reluctor ring i fitted had mushroomed slightly when I put it on. Garage has replaced the reluctor ring and put the genuine sensor on and so far all is well. No more faults.