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Discussion Starter #1 (Edited)
The other night I'm on the tollway at 180kmh in the E34 530i when I had to do some emergency braking (pick up truck in the fast lane doing 40kmh with no tail lights and cars in the middle lane ruling out a lane change) and I didn't see it until on top of the pickup as using low beam.

To my surprise the 530 locked the brakes and the car immediately kicked 10 degrees sideways until I eased off and stopped the wheels skidding to regain braking effectiveness and directional control (LHS front tyre slight flat spot), so it looks like both the fronts and the RHS rear locked up. I pulled up ok but it was a surprise to have the brakes lock up.

I've never had the 530 in a hard braking situation like that before so it appears the ABS isn't working but there's no warning light illuminated on the dash.

It's taken me a couple of years to trust the ABS system and stand on the brakes as I grew up on non ABS brakes.

I know the ABS works on my M5 and when one of the plastic sensor lead connectors broke I got an ABS warning.

Anyone had a no ABS no warning light situation ?

Is the ABS module easy to test/diagnose or is this something that needs to be done at the dealer ?
 

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The other night I'm on the tollway at 180kmh in the E34 530i when I had to do some emergency braking (pick up truck in the fast lane doing 40kmh with no tail lights and cars in the middle lane ruling out a lane change) and I didn't see it until on top of the pickup as using low beam.
This exactly what happend to my dad and me at least 17 years back ( I was a kid, 14 years old) but it was in a daylight situation. We were about the same speed as you in his old 535i e34 (with the Throwing Stars) going in the left lane when the fromt he nowhere the frigging truck at the right decided to change to the left lane with out any reason doing probably 40 km/h or so. My dad ******* the brakes, (we had a dig at the left of our lane all the way of the highway to "separate" the other highway) and the BMW locked up the brakes for fraction of time, it turned about those 10 degrees to left, direct to the dig and soon enough the ABS kicked and corrected the car keeping it stright in our lane and we avoided crashing against the truck and ending up in the dig or somethign worse.

That day, I realised the ABS how important and good was/is that system and felt in love because of that, we are alive today!

Back to the topic, yes, you should have an ABS light I think, however I don't remember if my M5 does have it in my cluster? I willcheck that...think I never seen that in my car).
 
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Discussion Starter #6
Is there bulb anymore? Sensor or abs ring problem, somebody remove bulb so buyer might not notice.
Yes , that's what I'm thinking , the bulb has been removed , I'll check later today.

I've done 18,000km in the 530i and never had a situation where I needed ABS (I still have 20/15 vision so I'm normally looking a long way ahead at traffic conditions and use very light braking early when I see the brake lights coming on 5 or 6 cars ahead).

The problem even at legal tollway speeds at night is these stupid trucks which have no or virtually no rear tail lights , in certain conditions they're invisible until you're very close, it's 'ok' when they stick to the slow lanes but occasionally you get a smart *** in the fast lane.

I've set a personal limit of 130 to 140kmh at night on the tollway now on low beam, I need to upgrade the headlights also, high beam on the E34 is ok but low beam is a bit dim , I also want to replace and re-aim the fog lights , we have no use for fog lights here but they would be useful as 'pot hole' lights at night.

Here's a Mercedes that slammed into a water tanker truck recently, at night the 'clear zone' on the inside lanes has probably got a truck hiding in there with no or low lights. Tollway lighting is patchy.
 

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check:

http://www.e38.org/e34/e34_94_etm.pdf

page 200 for ABS 530i/540i. Do you also have ASC?

Might be relay problems > ABS ECU doesn't get voltage supply and isn't able to switch the light on instrument cluster.

Since most of these cars don't get in to a phase that the ABS pump needs to work the pump remains sticky. Braking hard once in a while should make sure your pump remains active. ABS pump on E24 6 series are known with this issue.
 

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Discussion Starter #9
check:

http://www.e38.org/e34/e34_94_etm.pdf

page 200 for ABS 530i/540i. Do you also have ASC?

Might be relay problems > ABS ECU doesn't get voltage supply and isn't able to switch the light on instrument cluster.

Since most of these cars don't get in to a phase that the ABS pump needs to work the pump remains sticky. Braking hard once in a while should make sure your pump remains active. ABS pump on E24 6 series are known with this issue.
Thanks Tomba,

No ASC on this car
 

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Well I checked my B38 and does have the ABS light and it lights when IGN key is in ON for shortier period vs the the others lights.
 

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FWIW, I suspect the way the ABS light works is that it runs a self test on startup and only a success puts out the light. ie if the ECU isnt getting voltage then the self test would fail and the light should illuminate.

check:

http://www.e38.org/e34/e34_94_etm.pdf

page 200 for ABS 530i/540i. Do you also have ASC?

Might be relay problems > ABS ECU doesn't get voltage supply and isn't able to switch the light on instrument cluster.

Since most of these cars don't get in to a phase that the ABS pump needs to work the pump remains sticky. Braking hard once in a while should make sure your pump remains active. ABS pump on E24 6 series are known with this issue.
 

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Discussion Starter #12
Is there bulb anymore? Sensor or abs ring problem, somebody remove bulb so buyer might not notice.
Confirmed , ABS light has been removed.

I put a new globe in and the ABS light is permanently illuminated.

Note to self to pay more attention to the warning lights on start up hmmm
 

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FWIW, I suspect the way the ABS light works is that it runs a self test on startup and only a success puts out the light. ie if the ECU isnt getting voltage then the self test would fail and the light should illuminate.
If it doesn't get voltage there is nothing to switch (it simply can't due to lack of power supply). If it can't switch, it won't ground the light wire and the light won't go on. If the light should go on in cases like a disconnected ECU it should have a separate ECU which it hasn't.
 
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