W210 ABS BAS light triggered when pressing the horn!?

[Zakeroony]

Hi there,

Newbie to the forum so forgive me if this is obvious. As per the post title my E320 CDI (2001) Avantgarde has an intermittent fault where the engine revs drop momentarily when driving, knocks out cruise (it will re-engage) and flashes up ABS BAS "Visit the workshop" lights. Then goes out. Repeat.

Today, I noticed that when I press the horn I have no sound and the ABS and BAS lights kick off.

Took it to an independent Merc specialist and on diagnostic checking they said it had a strange fault about 'motion sensors'.

I'm thinking brake light switch but the horn triggering things is what I find confusing. This has all come about at the same time as my offside headlight failing. Swapped the bulb but no joy.

Hope that someone has some words of wisdom - I am not working at present and am getting quotes from breakers of 400 GBP for a complete headlight (gulp).

Thanks for any advice and suggestions.

Zak

 

[BlackC55]

I have seen this before.

Check the earth behind the headlight on the inner wing. It will be corroded I expect.

 

[Zakeroony]

I will do just that! Thank you for the tip. Will report back.

 

[renault12ts]

I agree...this happened to me...the earth fixing had rusted off...reattached elsewhere...all fixed. It's funny how the MB guys miss the obvious little things.

 

[johnsco]

I have seen this before.

Check the earth behind the headlight on the inner wing. It will be corroded I expect.

I've had just the same on the E430 (year 2002).
The horn, headlights or fog lights all triggered the ABS + BAS/ESP lights and caused loss of power.
A corroded earthing point behind the off-side head-lamp was the problem.

 

[Zakeroony]

Black C55 you are the man! Happy days. Found the earth fault was EXACTLY as you said. Many thanks. In fact, when I [technical term[ wiggled it the earth came off in my hand!

Suggestions now please on how to make a decent new earth that isnt going to see this reoccur on dark, wet and miserable night in the backend of nowhere?

 

[Zakeroony]

@BlackC55 and any others knowledgeable in this area... I have cleaned up the inner wing horizontal area (near the chassis leg - not at the strut top - this is where the earth had rotted off) and to my shock and horror have a hole about 10 cm long x 2 cm wide. Gulp. Is this an MOT failure?

Horrible place to get to weld up I imagine...

Unhappy

 

[renault12ts]

Yep...I was going to say that if the earth rusted off it would mean welding there...been there done that.

You'll have to remove the bumper, to remove the headlamp to gain access. You may even have to remove the wing (which will probably also need replacing anyway)...good luck.

 

[Zakeroony]

Thanks for coming back to me - and so fast. Gutted. Last thing I need right now is more cost. Going to get the earth sorted tomorrow to make the car driveable and worry about this when I have an income.

 

[Zakeroony]

Thanks for your help guys. Picture of the hole: https://www.flickr.com/photos/adrianzacher/15744922311/in/photostream/

Is this an MOT failure?

I can bite the bullet and get the wing off and replace the area (in time) but right now is really not a good time (stony broke)

 

[Zakeroony]

Thing I forgot to ask (should this be in electronic - but its kind of a continuation of this issue) is how to clear the ABS & BAS faults that are still flagged. Gone from 7 faults to 2 so making progress

 

[renault12ts]

Thanks for your help guys. Picture of the hole: https://www.flickr.com/photos/adrianzacher/15744922311/in/photostream/

Is this an MOT failure?

I can bite the bullet and get the wing off and replace the area (in time) but right now is really not a good time (stony broke)

That is rusted along the top of a brace which goes from the bumper to the chassis...chances are it is also shot and will have to be removed. If you are handy with a welder it's not too bad once you get at it.

The good news is the nearside doesn't seem to suffer the same way.

 

[Zakeroony]

You are right. The brace is pretty shot too. It will have to get on with it for now though.

Thanks for letting me know the nearside doesnt suffer in the same way. Phew!

And the ABS/BAS lights have settled down too. Thanks all for your very kind help, patience with my panic and advice.