ABS light is on

Most of the time you can just use the resistance option and spot the odd one out.

[...]

Yep. A half-decent DIYer, or a clued-up local garage would be able to carry out this type of diagnosis easily.

It's certainly a better starting point than taking a 15-year-old BMW to a main dealer for diagnosis, as has been suggested...

(As an aside, a local VW dealer has recently put his prices up to 95UKP

+VAT/hr!)

Chris

Chris Whelan gurgled happily, sounding much like they were saying:

£30/hr less than our local Audi dealer is reputed to be...

Yep, and a BMW dealer is likely to be more expensive still.

The car industry seems to be trying to cover its losses in the recession by increasing repair and servicing costs; parts prices are going through the roof.

Any reliable non-franchised garage ought to be in a very strong position.

Chris

that is fine till there is a bad situation. ABS equipped cars (may )have a different brake balance to a non abs car (when the abs is inoperative). I know this for certain from road testing ABS fault vehicles. When full braking is needed you may find that the car rotates rather rapidly. If you intend to go on using your faulty vehicle it would be a good idea to establish which end of the brakes will lock up first. If it is the rear end then it would be prudent to get the abs fixed. If it is the front then you should be fine.

& E36s are notorious for the pressure sensor in the valve block, you can get them reconditioned.

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.

But, don't believe anything you hear from random people like us on the internet. Go into a parking lot, get up a little speed and slam on the brakes and feel what happens. If the ABS triggers, you'll sure know it. If the ABS activates properly, you won't skid. If it activates improperly you may. Then you will actually know, rather than listening to people like us surmising.

--scott

I'm with Chris on this single point, the goal is a basic go-no go test. The wave form specifics are not critical because the wave form will either be, or not be.

It makes more sense to me to plug a diagnostic computer into the data link connector. No matter what the vintage of the car, the DLC will tell a qualified diagnostic program what is wrong. This, of course, means a trip to a BMW specialist. This is one of the things that can go wrong with my car that I can spend an afternoon trying to figure out, or have the trouble isolated in a few minutes and have the repairs completed in short order.

I'm not certain, but I believe a Peake scan tool will isolate this problem. You can pick up a Peake scanner from realoem.com or autohasaz.com or rockauto.com.

You could jack up each corner of the car, and test the output of each sensor, in less than an hour. At least I could, and I'm not a mechanic, and I'm coming up to 65 years of age.

I'm guessing you are in the US? I believe the OP is here in the UK, so things might be very different.

Firstly, you make an appointment with the dealer. At some times of year, it might take up to two weeks before they have a slot.

Then drop the car off, and wait half a day minimum for a call to tell you when you can pick it up.

It's likely that you would be charged for one hour of time. To put that into perspective, one hour of a BMW dealer's service time here would buy you a front ABS sensor, a rear ABS sensor *and* a usable DMM!

But at what cost? (Again, remembering the OP is in the UK, and this is a

15-year-old vehicle.)

Chris

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.

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.

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

Three years ago, my local BMW dealer wanted £130 + VAT per hour. Don't know what it is now.

No Thanks.

David

Technically, the government wanted the VAT, not the dealer. Technically.

I'm just saying that you gotta put the taxes due into the right heap. The dealer is only the messenger.

But, I still have to pay it.

Whereas businesses get to claim it back. Plus all the 'write downs' companies get against tax on company cars, whom the rest of us have to subsidise including pensioners unable to afford to properly heat their homes.

Rant over.

David

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

Sheesh!

DAS

The dealer has administrative costs associated with the collection and sending in of the VAT. VAT is not a dealer charge, and the government wants you to consider it as one so you are mad at the wrong party. If you thought of the VAT as a government fee along with the mountain of other governemnt fees, then you would be mad at the government. But if government can get you to be mad at the dealership for collecting the VAT, then the government is off the hook.

I'm not suggesting you simply swallow the VAT, I'm only suggesting that if you are going to be mad about it, be mad at the proper party -- the government.

But, yes, you have to pay VAT. My point is that it isn't a profit center for the dealership, so you should not look at the service fee as $100 + VAT, as if the VAT goes to the dealer. Collection and administration of the VAT is a cost center for the dealership, not a profit center. I'm certain that the dealership would love to stop collecting the VAT if it could.

Seems like you limeys had an issue some 250 years ago with taxation without representation. And you still have it.

There is a move afoot here in the Colonies to give us a VAT and do away with the Income Tax that we pay. As a small business -- _very_ small business, I think the VAT would probably drive me back to working for the man every night and day. I don't have the resources to collect and pay a VAT on the services I provide, and paying VAT on the services I consume is likely to cause me to raise my prices which will decrease my business and increase the percentage of costs to administer the VAT.