ABS light is on

Page 2 of 7  
snipped-for-privacy@panix.com (Scott Dorsey) wrote:


I did try that (actually on an otherwise empty road) and heard no ABS chatter. But I assumed that wasn't conclusive and that I really would need a slippery or a gravel or similar surface?
One significant development today: the ABS light did not come on, but instead I had a BRAKE LIGHT WARNING message on the computer. However, when I tested the brakes a few hours later with the car in the drive, the lights were OK.
Thanks for all the follow-ups. Its due into the garage tomorrow and I'll report back.
--
Terry, East Grinstead, UK

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

BRAKE LIGHT ERROR on the OBC display comes from either a brake light error -- look at all three of them -- or from the switch on the brake pedal that makes the lights come on. You can buy this switch for less than $20 (USD) and it takes under an hour to put it in. It might take you an hour, but the people that do this sort of thing can get it done in about 15 minutes.
I had this error on my first E36, and I would check the lights against a window. I had windows at ground level at my office, and could apply the brakes and see the lights come on. I took the brake light switch off and opened it up and cleaned it. The error went away and never came back.
This error will not affect the operation of the ABS system.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That seems pretty conclusive to me, but try it again once the ABS system is fixed so you can get a feel of how it triggers.

This is an unrelated problem but I'd pull all the brake light bulbs, clean them, pack them with dielectric grease and put them back and see if that solves it. The current relays in the black box that detects the bulb failures also fails, though, as does the switch. --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 18:48:31 -0000, Chris Whelan

Go on then ,when did you ever come across that?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 18:52:21 +0000, Duncan Wood wrote:

I never said I did.
I have seen an ABS control module where the electronic switching for the warning light had gone permanently closed though.
Chris
--
Remove prejudice to reply.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
gurgled happily,

That's a corner case. You should consider the ABS system out of service if the light is on. And in the instance you supposedly saw, the controller had a short in it that turned the light on, and there's no way to ascertain out here in the trenches that the short hadn't taken out some other significant part of the controller function.
The system design is that if the light is on, the system is off.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I think that you'll find this is an MOT failure now..
There is a firm who do very good recon's of these units. Used them last year on our Volvo 850 very quick service. There are others around might be an idea to give them a call..
http://www.ecutesting.com/index.html
--
Tony Sayer


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 18:52:21 -0000, "Duncan Wood"

It's a bit slim for *both* to happen.
I totally disconnected a low level switch from a screenwash tank fifteen years ago, the light on the dash never illuminated until a few weeks ago, now it does on an intermittent basis, sometimes flickering, sometimes solid for many hours.
...the wires are still disconnected and taped back at the tank.
Going back to the original poster, if the ABS light is low side switched, a simple short to earth as the wiring harness passes by a bracket or a piece of bodywork that should have rubber edging strip on it could do the same thing.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

But in that case the system doesn't "think" there's a fault. There's a fault that makes you "think" the system "thinks" there's a fault when it doesn't.
Where the system "thinks" there is a fault it will disable the ABS.
--
David Taylor

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Same thing.
If you cannot rely on the system working, then it does not work even if there is random functionality.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 10:49:12 -0800, Jeff Strickland wrote:

How is a working system with a malfunctioning fault indication the same as a broken system?
Chris
--
Remove prejudice to reply.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 18:52:44 -0000, Chris Whelan

Because it's malfunctioning, that means it's broken. Besides you can't usefully tell that that's the failure made so you're going to have to treat it as broken.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 18:58:34 +0000, Duncan Wood wrote:

Yep, but it still doesn't mean what the OP said:
"The ABS light being on means the ABS will not work"
Chris
--
Remove prejudice to reply.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 19:02:17 -0000, Chris Whelan

To all intents and purposes it does, in as much as turning the steering wheel will cause the steered wheels to move.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You're not laboring under the illusion that because the car stops then the ABS works, are you?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 04 Jan 2011 11:01:10 -0800, Jeff Strickland wrote:
[...]

What have I said that would make you think that?
Chris
--
Remove prejudice to reply.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sheesh!
DAS
--
To reply directly replace 'nospam' with 'schmetterling'
--
"Chris Whelan" < snipped-for-privacy@prejudicentlworld.com> wrote in message
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think some of the correspondence have difficulties in understanding more complex sentence constructions. :-)
I agree with your first comment, namely that one can't be absolutely certain that a failed light indicates a failed ABS system.
I don't think you claimed that one should ignore the light failure or anything else.
Many years ago I experienced an aircraft incident where the pilot had seen a warning light for a fault I cannot recollect. I discussed it with him when asking why our continuation of the journey after an intermediate stop was being delayed. He said that they were trying to determine if only the light was faulty (which would permit takeoff) or whether there was an underlying fault (no takeoff). Yes, many years ago, but the principle still holds.
DAS
--
To reply directly replace 'nospam' with 'schmetterling'
--
"Chris Whelan" < snipped-for-privacy@prejudicentlworld.com> wrote in message
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Years ago I was on a flying banana where the hydraulic pressure alarms kept going off constantly. The pilot kept resetting them and complaining about the stupid monitoring system.
I asked him how he knew it was a false alarm and not an actual hydraulic problem, and he pointed to some hydraulic fittings on the side of the fuselage. "See how that's dripping.... there's plenty of hydraulic pressure. When that stops leaking then there's a hydraulic pressure loss." --scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

That's right up there with, "the leaking engine isn't a problem, the problem is when the engine stops leaking."
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.