Bas/esp

[Measure Up]

Hi, These lights (BAS-ESP, ABS ) have been playing up the last few weeks on our ML270 whenever either the ABS or the ESP is activated and not going out at all until it is switched off. The other day, the ABS pump began to run continually and intermitantly with a mind of its own even with the engine switched off. Mercedes Benz have put it on their diagnostics and 'think' it may be the ABS pump which 'may' need replacing!! Has anyone got any knowledge or experience of this problem. Is the ABS pump module prone to failure or what would cause these problems? Or could it be a simple fuse?

 

[Myros]

You must get the codes read

if the clever types on here are to make sense of it.
You can of course check ALL the fuses in the interim. A very sensible thing to do.
If you have the results of the diagnostic check, which MB should have let you see and have if you paid for it ( even if it were a freebie, they should have let you see the results)post them up here and someone might know what's going on.

 

[Measure Up]

Thanks. Not got the fault codes as yet, but checked all the fuses, relays etc before it went in, with no luck. Not been able to collect the car yet either from the garage due to the weather. Hopefully they will be ble to give me the codes. Thanks again.

 

[Myros]

make sure they do

as it will help narrow things down considerably ( we hope)
Good luck with it.

 

[television]

Possibly a bad connection on the PCB on the ABS pump

 

[Alex Crow]

some of these did suffer with chafing of the loom near the pump, where it goes by the inner wheel arch trim. also have seen corroded connectors on these too - the pump location on the ML makes it a little vulnerable.

 

[Measure Up]

Sorted thanks to all, MB cleared all the codes and we went through all the relays.... again. The ABS pump relay has been changed and ESP, ABS BAS lights etc have all gone out and normal sservice is resumed thankfully without the need to replace the pump!!!! There you go a £27 relay. Although having looked how vulnerable the pump is underneath the washer reservoir etc, I'm well pleased it hadn't gone. Thanks again.

 

[television]

That was an unusual fault and that must be remembered..Pleased its fixed

 

[Alex Crow]

if this was a relay in the main fuse/relay module behind the washer reservoir, i am not too surprised. we have seen many problems with these relays over the years, affecting various systems on the car.

 

[greenfingers]

My first post in ages after enjoying trouble free motoring in the ML.
Pleased that Myros eventually got to the bottom of his nightmare.
I have a similar predicament, and after reading everyone elses accounts of their own BAS/ESP solutions, I am even more confused.

Over the last few days, the dashboard has periodically had more lights on it than our demised Christmas tree. Namely:- BAS/ESP, ETS, ABS, and EPC.
I haven't tried crawling around in the snow to investigate as yet, but according to other posts it sounds like there are a number of possible causes.

I wonder if all the other victims had all their brake/traction related lights come on together or not, and whether I could therefore eliminate some of the causes. I have a strong feeling that this is not a mechanical fault since the lights can come on or go off at random and even at a standstill. What is certain is that the ABS and traction control are not working when the lights are on.

It is interesting to hear that corrosion or poor contacts on the ABS unit are a possibility, because when the washer bottle is more than 3/4 full it has a slight leak, and oddly enough I topped it up with additive for the cold weather recently. Could the water have dripped onto the ABS electrics?

I would be grateful for any suggestions and it would be particularly helpful if someone (Malcolm?) could point me towards a wiring diagram.

I've just got to add gleefully that the ML has been amazing in the snow - even when flooring the throttle on slopes that 2WDs can't get up, it just lurches off with no apparent wheelspin. The ABS works brilliantly too: I have a van with ABS and it cannot compare in terms of stopping on snow - you just end up sliding into the verge.
It really makes you appreciate the benefits of having these features when they are working.

 

[television]

If you have the ESP BAS and ABS lamps on,,then the fault must be in the Base module or system the ABS, as both of the other 2 things ride on top of the ABS

 

[greenfingers]

Thanks Malcolm, I barely had time to make a cup of coffee!

So do you think that thing under the washer bottle could be the culprit? I don't relish getting at it. And does that mean the brake light switch can be eliminated?

 

[television]

Thanks Malcolm, I barely had time to make a cup of coffee!

So do you think that thing under the washer bottle could be the culprit? I don't relish getting at it. And does that mean the brake light switch can be eliminated?

Yes the brake lamp switch will do nothing for ABS as this is not a true CAN item as such. could be a wheel sensor or the ABS pump or ECU if fitted. There is always some kind of protection offered for the expensive ABS components, and I will try and see if there is any documentation on this tonight

 

[greenfingers]

Yes the brake lamp switch will do nothing for ABS as this is not a true CAN item as such. could be a wheel sensor or the ABS pump or ECU if fitted. There is always some kind of protection offered for the expensive ABS components, and I will try and see if there is any documentation on this tonight

Thanks, then I will firstly try to crawl underneath tomorrow and check if any of the wheel sensors or their connectors seem loose.

 

[television]

I have done some searching around,,(I do not know much on the 163) There is the N10 AAM all activity module. It is known that the connections on the ESP module can corrode and an application of a good switch cleaner would do no harm on this..

This is one of those cars so different to anything else and a working knowledge would be a boon

 

[Myros]

I still have an ESP control unit

which I bought for mine somewhere. If that's what you end up needing, and if it's compatible, then I'm sure we can come to an arrangement.

 

[Measure Up]

I'm sure you have already, BUT double check the relays in the main fuse box and then check them again!! Have you got any whirring noises when you switch off the car. I did latterly after the faultlights had been on a week. It was the relay sending messages to the ABS pump module and knocking off the ESP/ BAS and ABS. Apparently however, the pumps are well known to fail on the 270's and 320's apparently due to the reservoir leaking water into the black box on the left handside and damaging the contacts.
Good luck with it. Sent me grey!

 

[television]

My ABS pump went down on the V70R last year,,I cut it open and re soldered the connector socket to the PCB and glued it back up and it has been perfect ever since.

I had nothing to lose

 

[greenfingers]

I'm sure you have already, BUT double check the relays in the main fuse box and then check them again!! Have you got any whirring noises when you switch off the car. I did latterly after the faultlights had been on a week. It was the relay sending messages to the ABS pump module and knocking off the ESP/ BAS and ABS. Apparently however, the pumps are well known to fail on the 270's and 320's apparently due to the reservoir leaking water into the black box on the left handside and damaging the contacts.
Good luck with it. Sent me grey!

WOW, yes I am getting a kind of whirring noise somewhere in the engine compartment after switching the engine off. I remember noticing it the other day for the first time and then thinking nothing of it. The sound is a sort of buzzing, which has now got me thinking about relays.
Thanks Measure Up, I will investigate in the morning.

 

[kgd]

changed the instrument panel today on my C220cd1 (w202) and the bas light remains on
is this because the steering wheel wasnt lined up properly - I did mark it but maybe a spline or two out
How do I rectify this?
any help appreciated