2012 SLK 250 R172 - ESP, ABS lights on

[Kewickviper]

I bought a 6 year old SLK 250 a few weeks ago and within a week of buying all the warning lights for ABS and traction control started coming on. Initially they only came on occasionally, but now they're on all the time and also the parking break light occasionally comes on while driving. It had recently (August) been for a Mercedes service so I would have thought anything hidden like this would have shown up on the report had it been known before.

I bought a Creader VII+ scan tool and got a load of codes come up - some for internal issue with esp module, one about fuel intake not being clear and a bunch for components not getting enough voltage. I cleared the codes and drove around for a couple days to see what would come back. The eco stop/start function on the car hadn't worked since I'd bought it and upon lifting the hood I saw it still had the now almost 7 year old original Mercedes battery still installed. So I replaced the battery a few days ago and I now have the following codes which come on every time:

ME - Motor Electronics
- C003100 - The fault code is not found in the database.
- C003164 - The left front wheel speed sensor has a malfunction. There is an implausible signal.
- C003400 - The fault code is not found in the database.
- C003464 - The right front wheel speed sensor has a malfunction. There is an implausible signal.

Transmission
- D40A - The right front wheel speed signal from the traction system is not available on the CAN bus.
- D409 - The left front wheel speed signal from the traction system is not available on the CAN bus.

ESP(

- C110200 - The signal of component 'L6/1(Left front axle rpm sensor)' is implausible.
- C327100 - Implausible values of rpm sensors: speed at front axle.
- C111000 - Component 'L6/2(Right front axle rpm sensor)' has an electrical fault.
- C111700 - The signal of component 'L6/2(Right front axle rpm sensor)' is implausible.
- C110700 - The signal of component 'L6/1(Left front axle rpm sensor') is implausible.
- C120000 - The power supply for component 'B64/1(Brake vaccum sensor)' is not OK.
- C326600 - Consequential fault.

SRS
- No Fault codes.

VIN - WDD1724472F031686

If I reset the lights everything works fine until I drive a little way down the road, and then they all come on again. It seems odd to me that all of these sensors can go out at the same time so I'm thinking maybe it's some kind of connection fault to the ESP control unit, however I'm not sure where to start checking for that. What also seems strange to me is that if I go into the data stream function I can see that values are correctly being received on all 4 of the wheel speed sensors and also the brake vacuum sensor so I'm not sure what's causing these faults to flag up.

I've managed to find some abs sensors which are quite cheap from here: https://www.onlinecarparts.co.uk/ca...enz/slk-r172/7503/10138/abs-sensor.html#10110 but I don't want to go out and buy some before checking the connections.

I'm also worried about the fault: "The power supply for component 'B64/1(Brake vaccum sensor)' is not OK." does this mean I need a new brake vaccum sensor or just that the fuse/connection is faulty?

Any help would be greatly appreciated as I'm pretty new to any sort of car DIY.

 

[Bobclive2]

Wheel speed sensor probably, easy fix.

 

[HITECH]

I bought a 6 year old SLK 250 a few weeks ago and within a week of buying all the warning lights for ABS and traction control started coming on. Initially they only came on occasionally, but now they're on all the time and also the parking break light occasionally comes on while driving. It had recently (August) been for a Mercedes service so I would have thought anything hidden like this would have shown up on the report had it been known before.

I bought a Creader VII+ scan tool and got a load of codes come up - some for internal issue with esp module, one about fuel intake not being clear and a bunch for components not getting enough voltage. I cleared the codes and drove around for a couple days to see what would come back. The eco stop/start function on the car hadn't worked since I'd bought it and upon lifting the hood I saw it still had the now almost 7 year old original Mercedes battery still installed. So I replaced the battery a few days ago and I now have the following codes which come on every time:

ME - Motor Electronics
- C003100 - The fault code is not found in the database.
- C003164 - The left front wheel speed sensor has a malfunction. There is an implausible signal.
- C003400 - The fault code is not found in the database.
- C003464 - The right front wheel speed sensor has a malfunction. There is an implausible signal.

Transmission
- D40A - The right front wheel speed signal from the traction system is not available on the CAN bus.
- D409 - The left front wheel speed signal from the traction system is not available on the CAN bus.

ESP(

- C110200 - The signal of component 'L6/1(Left front axle rpm sensor)' is implausible.
- C327100 - Implausible values of rpm sensors: speed at front axle.
- C111000 - Component 'L6/2(Right front axle rpm sensor)' has an electrical fault.
- C111700 - The signal of component 'L6/2(Right front axle rpm sensor)' is implausible.
- C110700 - The signal of component 'L6/1(Left front axle rpm sensor') is implausible.
- C120000 - The power supply for component 'B64/1(Brake vaccum sensor)' is not OK.
- C326600 - Consequential fault.

SRS
- No Fault codes.

VIN - WDD1724472F031686

If I reset the lights everything works fine until I drive a little way down the road, and then they all come on again. It seems odd to me that all of these sensors can go out at the same time so I'm thinking maybe it's some kind of connection fault to the ESP control unit, however I'm not sure where to start checking for that. What also seems strange to me is that if I go into the data stream function I can see that values are correctly being received on all 4 of the wheel speed sensors and also the brake vacuum sensor so I'm not sure what's causing these faults to flag up.

I've managed to find some abs sensors which are quite cheap from here: https://www.onlinecarparts.co.uk/ca...enz/slk-r172/7503/10138/abs-sensor.html#10110 but I don't want to go out and buy some before checking the connections.

I'm also worried about the fault: "The power supply for component 'B64/1(Brake vaccum sensor)' is not OK." does this mean I need a new brake vaccum sensor or just that the fuse/connection is faulty?

Any help would be greatly appreciated as I'm pretty new to any sort of car DIY.

REPLACE your front wheel speed sensors and job will be a good un. You have driven thru too many potholes or flown over too many speed bumps without slowing down lol. but seriously replace both front wheel speed sensors as suggested by somebody else in here. I can give you some very experienced advice concerning ABS systems and wheel speed sensors. DO NOT BUY CHEAP AFTERMARKET CHEAP SENSORS. they will not fix your problem with your mercedes and like many others it will lead you up the garden path to think it is something else when it isnt. Buy mercedes sensors. If you clear the code and at a stand still the car is fine and clear, then lights come on when you hit 10mph, Yes that is a wheel speed sensor or in your case as the DTC codes say, it is both front sensors.

 

[markjay]

As above.

Or, If you bought the car from a trader (as opposed to a private sale), just take it back to where you bought it from and ask them to fix it under you're statutory rights as per the Consumer Rights Act 2015.

But if you did buy it in a private sale and have no come back, then get BOTH front wheel speed sensors replaced, because if you don't then the other one will follow soon.

(Obviously you can't realistically expect a dealer to preemptively replace FOC under the statutory warranty the sensor that hasn't failed yet)

 

[pioneercollector]

I would also look at the wheel speed sensors, I had a similar issue with my SL500, lots of ESP / ABS warnings, and then 60 miles from home 'limp mode' ( basically locked the gearbox in 3rd ) ... quick go on STAR, and a rest and clear, and new sensors - all good!