W211 ESP,ABS SBC Faults & Battery

[211Stu]

Im new here so first off hello

I am having issues with my 03 W211 320CDI (199,620miles)
I will list them each but maybe some are caused by the same issue?

1. ABS Not working
2. ESP Not working
3. SBC hold Not working
4. Brake service - All fine replacements front and back with in the last 12 month (SBC counter maxed?)
5. Battery warning on start up with disabled convenience functions for a limited time.

The main battery in the boot reads 12.5+/- 0.2v and has a clean bill of health after health testing (even tried a new battery and no change)

Small battery under bonnet reads around the same 12.5+/- 0.2v and again ok after a health check.

From the on board computer on start i get as above 12.5v ish then a dip to around 10v while cranking and then upto around 13.5v+ after a few sec so i can see the alternator is working.

Its not that the battery is dead as such as its never not started or even shown a low enough voltage for me to be worried about as i have been keeping my eye on it for a while now.

Dont really know where to go from here, i am taking it to maindealer to see what they think next week but to be honest if its going to cost a fortune (£1000s) then maybe i will think about getting a new car.

My SBC unit (Bosch 0 265 960 018 - hw05/03 sw16/03) are they covered under a warranty or max 10yr?

big post but i have tired to provide as much detail as i can, thanks for any input.

 

[OneForTheRoad]

I used to suffer this --- disabled convenience functions for a limited time .. one day whilst cleaning the car I had the radio on for 30 mins , the whole dash went berserk , the clock started going backwards and the dash turned red . the car wouldn't even turn over , I luckily had a spare brand new bosch battery which I fitted and ever since ive had no problems at all . id think even a dead battery would read 12 volts tbh , its the amp age its holding which is the important factor . id replace the battery and check the smaller battery date , if its old change that also . your sbc serial is dated may 1992 . try charging the main battery for 24 hours and see if things improve.

 

[211Stu]

i had replaced the main battery and left it on the car for around a day and a half, also used the car in the time mixture of town/motorway driving nothing changed.
I may buy a the smaller battery and see of that changes anything.

 

[HB]

Alternator may be the cause. I just replaced myn after same issues as yours. My car is similar in age to yours and these things will eventually go wonky.
The car is brill again. No issues.

 

[John]

Welcome to the forum.

Mine also had issues with the main battery originally (I'd look at the date of your existing battery) and then the alternator.

Plays havoc with the car.

Dont really know where to go from here, i am taking it to maindealer to see what they think next week but to be honest if its going to cost a fortune (£1000s) then maybe i will think about getting a new car.

My SBC unit (Bosch 0 265 960 018 - hw05/03 sw16/03) are they covered under a warranty or max 10yr?

I'd find a good independent - unless you like spending money.

Forget the warranty on SBC. They dropped that idea a long time ago.

Get it checked out first by a good inde...

 

[Deleted member 37751]

I've had this a couple of times in different 211's and each time it was the auxiliary battery at fault.

They're only around £50-60 from the main dealer.

 

[cliveBRABUS]

I would get it put on STAR

 

[Stratman]

I'd like to see slightly higher voltages both off load and while charging.

Off load a lead acid battery should be 13.2V (6 cells of 2.2V in series) and 14.2V when running and being charged.

 

[E55BOF]

used the car in the time mixture of town/motorway driving nothing changed.

What distance did you cover? A decent run might well sort it out for a while; the symptoms you have certainly point to a failing, or low on charge, auxiliary battery.

Apart, that is, from SBC Hold not working - I don't think that is a convenience function. How long have you had the car, and was the SBC Hold function working previously? If not, and I intend no offence, is it possible your technique for engaging it is incorrect? You should also have SBC Stop on your car; is that working?

If the car is still on its original SBC unit after that mileage, it must have done a lot of its miles on the motorway in traffic-free running. The serial number seems to indicate it's a very early unit, but I don't know that for sure. Do a search in the Parts, Maintenance & Servicing forum for <Checking the SBC - SL?>, and the thread you bring up has all the info you need to establish the age of the unit.

 

[b1g1an]

Convenience function is rear battery, hold not working and red lights is front battery. Whether it's actually duff batteries, lack of use or the alternator causing them to be undercharged though is more difficult to diagnose.

Giving them both a decent charge and see what happens is best place to start.

 

[cazyp]

As Stratman said 12.5v is too low for your main battery.

 

[HB]

I had all these faults. It's the alternator and batteries , trust me.

 

[211Stu]

I got a new battery for the front and its made no difference, had my rear battery checked again from another garage and they say its fine.

getting 13.9v when driving.

 

[John]

13.9v when running sounds OK.

You need to find a good inde.

Post up where you are based...

 

[4life211]

How to stop a W211 in case of SBC failure ?

 

[E270 Owner]

1. Throw ships anchor out of the window

2. Both feet on brake pedal push hard and pull hard on bottom of steering wheel with both hands.
(depending on speed at time of failure)

 

[OneForTheRoad]

it has enough pressure to bring the car to a stop - 1 time only , I read somewhere . I have also read other horror stories of grown men pooping themselves when the sbc fails .

 

[mersum1es]

In emergency mode pedal actuates master piston directly (usually no actuation between pressurized circuit but brake force 'simulator' only) and electric valves open emergency circuit, power is absolutely not boosted which means only fraction of braking power left. These few 'pedal to floor' cases reported, IDK what wrong with system them, either jamming valves or air content in circuit...

 

[4life211]

In emergency mode pedal actuates master piston directly (usually no actuation between pressurized circuit but brake force 'simulator' only) and electric valves open emergency circuit, power is absolutely not boosted which means only fraction of braking power left. These few 'pedal to floor' cases reported, IDK what wrong with system them, either jamming valves or air content in circuit...

I have this case to myself.I have E270 cdi 2003, and my SBC failed .Fortunately I was in low speed 10 mil/h and I stoped it with hand brakes.I take it to service shop with hand brakes.But what can happend if you are in highway and SBC failed ????Where is the safety of merc ???

 

[211Stu]

just remember i posted this, just a update to say my battery issues and convenience function prob have been solved i replaced the voltage regulator, cost £35 delivered for a Bosch one took me about 2 hrs.

though it was worth a mention if people have the same issue this was a fix for me.