W203 C270Cdi ABS/EPC/BAS/ESP warnings

[charl39]

Morning all

I have an intermittent problem with these warning messages. My 2002 C270CDi (151,000 miles) is otherwise brilliantly reliable, but over the past few weeks I've had the problem of these warnings going on. What happens is this:

• First of all the EPC and BAS warnings go on, a few minutes after starting the car in the morning.
• Next, after about 10 miles, the ABS and ESC warnings go on.
• All four of these warnings stay on every time I start the car. The cruise control doesn't work either (but the autobox does change gears just fine.)
• I take it to my local (independent) garage to look at it. They scratch their heads, try to reset the codes, which doesn't (apparently) work, and I take the car away again with the warnings still showing.
• Miraculously, the next time I start the car, the warnings have disappeared, and stay off, for about a week. Then it happens all over again.
• According to the garage, it could be a faulty sensor encased in a ring in the rear wheel assembly. The part itself is cheap, but they say tha to fit it, the driveshaft has to come off first, which risks damaging it.

Now I don't mind spending a little money on the car to keep it on the road (I recently had new tyres and a new battery - the battery was the first thing I had done after these warnings started) but the car is frankly not worth much more than £750 so if they break my driveshaft that's it for the car. I don't want to risk it; but I also don't want to go off to the Mercedes dealer for them to charge me hundreds of £££ either with the possibility of not fixing it. To be honest I have a very good relationship with my local garage; they have looked after the car for 12 years so far, and they don't rip me off.

Does anyone have an idea of what actually might be the cause of this? Or alternatively, of a workshop in the Oxfordshire area who are any good at this sort of thing?

I love my car and am very reluctant to replace it. I could never replace it with the modern equivalent anyway - I just can't afford that any more. The MOT is due in March and I obviously need to sort it out before then.

Thanks for your collective wisdom!

 

[Wighty]

Morning all

I have an intermittent problem with these warning messages. My 2002 C270CDi (151,000 miles) is otherwise brilliantly reliable, but over the past few weeks I've had the problem of these warnings going on. What happens is this:

• First of all the EPC and BAS warnings go on, a few minutes after starting the car in the morning.
• Next, after about 10 miles, the ABS and ESC warnings go on.
• All four of these warnings stay on every time I start the car. The cruise control doesn't work either (but the autobox does change gears just fine.)
• I take it to my local (independent) garage to look at it. They scratch their heads, try to reset the codes, which doesn't (apparently) work, and I take the car away again with the warnings still showing.
• Miraculously, the next time I start the car, the warnings have disappeared, and stay off, for about a week. Then it happens all over again.
• According to the garage, it could be a faulty sensor encased in a ring in the rear wheel assembly. The part itself is cheap, but they say tha to fit it, the driveshaft has to come off first, which risks damaging it.

Now I don't mind spending a little money on the car to keep it on the road (I recently had new tyres and a new battery - the battery was the first thing I had done after these warnings started) but the car is frankly not worth much more than £750 so if they break my driveshaft that's it for the car. I don't want to risk it; but I also don't want to go off to the Mercedes dealer for them to charge me hundreds of £££ either with the possibility of not fixing it. To be honest I have a very good relationship with my local garage; they have looked after the car for 12 years so far, and they don't rip me off.

Does anyone have an idea of what actually might be the cause of this? Or alternatively, of a workshop in the Oxfordshire area who are any good at this sort of thing?

I love my car and am very reluctant to replace it. I could never replace it with the modern equivalent anyway - I just can't afford that any more. The MOT is due in March and I obviously need to sort it out before then.

Thanks for your collective wisdom!

Ian at Star Mercedes in Reading is one of regular Indys on this site . You really need the car diagnosed by a Mercedes Star/Xentry computer to pin it down . I haven't heard of the driveshaft coming off to do the sensor (but who knows) .
Some of the symptoms you have I had a year ago with a £11 Brake stop switch that took 5 mins to change , but as with all these things a Merc expert like Ian is the way to go .

 

[alexanderfoti]

It sounds like they are talking about the reluctor ring, but the codes would indicate which wheel is causing the fault, and they could visually examine it by removing the wheel speed sensor.

You mention EPC warnings in your title, but not in the main post?

EPC warning can be caused by throttle pedal faults, or fuel system faults, so its important to rule that out.

ABS/ESP/BAS are all affected by wheel speed issues, and when you have all three faults at once, its what I would look at.

Brake light switch not a bad shout!

 

[om613]

Are the new tyres the right size, rolling radius-wise?
(Although with that fault, it will not go away for a week before it reappears).

Yes, the brake light switch is worth changing, u/s cruise is the usual sign.