2001 C320 ABS ESP BAS warning light then limp mode

[mattyv33]

Hi all, bought a 2001 W203 C320 a month back. A couple of days later I got the ABS ESP BAS warning light followed by visit workshop and the car went into limp mode.

Great, I thought, here we go. I stopped, turned it off and started it up and everything cleared. The car ran as normal for 2 weeks before it did the same. Did the usual turn it of and on and all faults cleared and drove as normal. Happened the day after (last Sat) and has not happened since.

I am wondering if this could be something simple as a corroded wire or bad sensor - not sure where to start or what to look for but this fault is annoying because each time I have to pull over to a stop and restart.

Hoping you guys can assist!

I also have another two faults.

1. When the car is stationary, the idle is unsteady and the car appears to shake. You can see the idle going up and down.

2. The add oil warning light comes on saying add 1.5l - I add about 500mls and it goes off and says oil OK. It will come on again in a few weeks. No evidence of oil leaks.

Hoping this may be a sensor too - I read the is a sensor that can be changed when you change the oil?

Apart from this issues, the cars great!!

Thanks in advance

 

[babaroga]

1. It could be a few things, including MAF sensor sending wrong data. Try unplugging MAF and then start the car, as a first try. It could be mechanical also where one of things like alternator, power steering pump or AC compressor is going to give up the ghost and ceasing up. Not sure if your engine has Idle Control Valve.

2. It could be the oil level sensor. Try using dipstick to check OIL rate and compare with on screen. How often do you need to top up oil? I still trust dipstick more than that electronic sensor.


Now, ABS ESP BAS. Not sure on Merc, but Land Rover used to have "three amigos" that would govern above functions. It can be as simple as ABS sensor on the wheel to losing earth connection somewhere. Those sensors are used for many things, not ABS function only.

Maybe you should get someone with Star to have a play to start with....

 

[Mistreku]

For the BAS ESP error, you should probably replace the brake light switch (behind the brake pedal, under the dash, 10 min job). It's a common fault on W203/W208, apparently. Make sure you get a genuine one, as aftermarket ones will fail pretty quickly (ask me how I know).

The rough idle could be down to more than one thing. MAF (as suggested, try running the car with it disconnected, if it runs better, then it's probably on its way), could also be the coils/spark plugs. Does it run smooth in higher RPM's? If not, I'd have a good look at the coils. Also, O2 sensors could cause this rough idle, I had similar issues with my previous car, both rough idle and poor acceleration/MPG's, they were fixed with replacing O2 sensors. Does the idle hunt at all (going up and down by itself)? Or it's more like small misfires when idling with a little shaking?

I'm not very knowledgeable either, I'm afraid, but I'm sure if you provide more details regarding this idle issue, someone more experienced with MB's will come up with a solution.

Gab

 

[mattyv33]

Thanks for the replies, what happens with the abs bad esp error is that you will be driving normally then all of the lights come on the dashboard - abs bad esp brake lining visit workshop then it will only drive in one gear. Also at the same time the speedometer stops working and stays at 0mph.

It hasn't done it since last Sunday now, car driving as normal. I will replace the brake light switch as suggested, there is a mercedes garage near me called Merx - thinking of taking it there to plug in - may throw some light on the rough idle?

The rough idle is getting worse, when stationary the car wobbled and you can hear the engine revving up and down slightly - can also see it on the dash. When creeping along it still shakes but as soon as you put your foot down it drives perfect!

 

[Mistreku]

You can do the brake switch job yourself, is very easy, all you need is a screwdriver. The switch, itself, costs around 15 pounds. If you decide to do it yourself, there's plenty of DIY's around. The error will pop more often in time and will eventually go to the point where it will be present as soon as you start the car. Being such an easy and cheap job, I'd say the sooner you fix it, the better.

As for the rough idle, since the car runs as it's supposed to do while in gear, I'd look for an air leak (cracked/disconnected hoses, loose clamps). A less likely scenario would be leaky injectors, but really, I wouldn't go that far with the suppositions. IMO, it will be just an air leak which disturb the idle AFR.

Keep us posted.

Gab