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Abs control unit

3K views 23 replies 6 participants last post by  bluebee 
#1 ·
I just recently went to the bmw shop & they told me I need a new abs control unit & it'll be cheaper to order it online, The problem is I don't know were to order it & if it needs to be brand new to turn off my abs light ? Can someone help me & also show me what they might look like so I know exactly what to order cause every time I search it up on eBay a few different things pop up ? I have a 528i , year is a 99 .
 
#2 ·
You probably do not need a new ABS control unit.

Most mechanics believe their instruments, instead of knowing what we know:
- Is it possible for diagnostic tools (such as INPA, PASoft, Carsoft, etc.) connected to the OBD/Pacman port to correctly diagnose the ABS BRAKE DSC/ASC trifecta (1)

Luckily, EVERY SINGLE E39 ever built (almost) has had this problem.
So, start here:
- How to run the canonical quick test of the ABS BRAKE DSC/ASC trifecta or bifecta (1)

And then, if that tests shows it to be the ABS control module, then go here:
- What are all known options when your ABS control module is bad (1)
 
#3 ·
What was the reason you need a unit what testing did they do? You can read bluebees write up on this unit and certainly they have problems but yours sound like better know the reason why first. This really could be a bad sensor and not a unit but you didn't give and information.
 
#4 ·
Yeah I read bbs post & it kinda helps I guess but I took it to a bmw specialist & he didn't say the whole module was bad he told me to just order a control unit online & take it back & they'll install it for me but I'm not sure what testing they did I assumed they just used the obd & read the codes ? I don't have a check engine light or any of that its just the dsc & abs & traction
 
#8 · (Edited)
Yeah I read bbs post & it kinda helps
Think about this.
You can pay upwards of $1000 to replace your ABS control module and wheel speed sensors; or, you can read the entire thread (not that one post) and maybe get away for from zero to about $450 dollars (most likely around $100).

NOTE: The reason the post only "kind of" helped is that it's a single post. No one post is going to answer all your questions and get you up to speed on this issue.

he didn't say the whole module was bad he told me to just order a control unit online
If you read that thread, you'll realize that sentence makes absolutely no sense.
they'll install it for me
Again, if you read the thread, you'll know that it takes less than five minutes to "install" it. In fact, it takes about one or two minutes, and needs only one torx driver, which you should already have in your toolbox.

but I'm not sure what testing they did I assumed they just used the obd & read the codes ?
If you read the thread, you'd realize this has NOTHING to do with OBD (which is for emissions).

In other words, there are no OBD codes (well, there's that P0500 but that comes later and it's detailed in the thread anyway).

I don't have a check engine light or any of that its just the dsc & abs & traction
Now I'm frustrated.

Even if you read only the POST, you'd know there is no check engine light.

So, my suggestion is the following step-by-step DIY:

  1. Sit down at the desktop computer
  2. Put your wallet away in the desktop drawer
  3. Read any or all of the following threads, to completion
- How to physically test & repair the Bosch ABS control module (1) & how to diagnose the BMW amber ABS BRAKE DSC/ASC trifecta or bifecta (1) & what are all known options when your ABS control module is bad (1) & why you want to only buy oem wheel speed sensors (1) & how to remove and replace the four BMW E39 ABS related WSS wheel speed sensors (1) & which wss innervates the speedometer (1) & explanations by 540iman as to why the fancy diagnostic tools always fail to properly diagnose the trifecta or bifecta (1) & where to get the fancy schmancy diagnostic tools for free once you're aware of their limitations (1) & why it's probably not the ABS hydraulic pump failing (1) & how to properly test the BPS brake pressure sensor (1) & how to properly test and replace the steering angle sensor (1) & Quick99Si's explanation of why the 10-minute wheel speed sensor diode-action quick test doesn't always work, especially on non-OEM wheel speed sensors (1) & what's this about the P0500 setting the SES (1) & why you want to wait a week before getting a smog test after removing your ABS control module (1) &, if you really want to try, how to attempt to disable the ABS/DSC but keep the speedometer and mpg cluster readouts (1)

Caption: Here is a picture of my "repaired' ABS control module.
 

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#7 ·
Unfortunately the abs unit when it fails does not have a code that says the unit failed in some cases intermittent shorts give all kinds of problems and this would be a reason to consider the control unit. Has anything in the abs system been repaired before or can they at least tell you what they tried for example if they tried sensors with no change...etc
 
#9 ·
Since I have gotten it no I'm not sure but it seems to me everything is all original with no repairs but I could be wrong, & I can ask them but I'm not in that area anymore it's like a 30 minute drive . Should I just take it into consideration & buy the control unit ? I really need the light to turn off so I can get my tags
 
#10 ·
I really need the light to turn off so I can get my tags
Tags?

What state are you in?

NOTE: It matters, depending on the state, for this issue (and your CP doesn't say).
 
#12 · (Edited)
I thought so, since you used the odd word "tags" (which I have only heard out here).

IIRC, California law proscribes a seller selling a car that requires inspection within 90 days of the sale that does not pass inspection.

Another way of saying that is that California law prescribes that the seller pay for fixing the car so that it can pass inspection.

I think the details are in this thread (but we'd have to check since you failed, not for OBD, but for something else):
- What states make it illegal to sell a car "as is" that won't pass smog or that have an SES/CEL light lit at the time of sale (1)

NOTE: Please post your smog results to that thread, since your payment for our help is to help others by documenting what it is you do.
- A compendium of BMW E39 emission smog test results (1)
 
#14 ·
I would suggest you let the shop order, install and code the ABS module. This will cost more, but it will be done correctly and the shop will be fully responsible for any issues.

If you order the part, what happens if you order the wrong one? Some cars have DSC, some have ASC and the ABS models are different.
 
#18 ·
I would suggest you let the shop order, install and code the ABS module. This will cost more, but it will be done correctly and the shop will be fully responsible for any issues.
How do we even know that the ABS control module is bad?
It could as well be a wheel speed sensor, from what we're told, so far.

Either way, it should cost the user about $100 to fix.

If you order the part, what happens if you order the wrong one? Some cars have DSC, some have ASC and the ABS models are different.
That's not really a realistic problem, for two different reasons:
1. You almost NEVER need a "new" ABS control module!
2. Even if you did need a new (or rebuilt) module, any reputable supplier will doublecheck that the parts are correct.

It's the same problem you'd have with almost ANY part on the car.
You can't be afraid of ordering anything just because of the FUD involved in getting the part number correct.

Besides, realoem will tell the OP the exact part number in fifteen seconds, so, where is the risk?

I past my smog test though it wasn't the smog I failed , there switching over my pinks to salvaged & in order to do that I had to get a break & light inspection which I failed & in order to pass the place that inspected my car said I had to get the abs light turned off & then they can pass me .
OK. So it's more complicated than a normal smog.

Then, all I can recommend is that it behooves you to call someone up on Sacramento (plenty of phone numbers are on the links I already provided) to see if the SELLER is responsible for the cost of your car getting properly tagged.

I think they are; and, unless you show otherwise, I don't see this problem being any different (although, I agree, it's more complicated than your standard car sale because of the word "salvage" and what that might mean in terms of the applicability of the law).

I know I don't want to order the wrong part that's why I got on here & was asking
First off, you don't need to order a new one, and second off, even if you did, it's so easy, that you need to follow this DIY below:

  1. Write down the last 7 digits of your VIN
  2. Point your browser to RealOEM and enter those digits where it asks
  3. Find the part number for your particular car
Here's mine, for example, for DSC, when I typed in my VIN into that engine just now:

I'm not sure what I should do I just really need my car & I need the light turned off before I can get my tags
It's trivially easy to figure out what to do, but you have to read a bit to find what everyone else did who was faced with the exact same problem.

Remember, this has happened to almost every E39 out there, so what we do is already well known (and I already pointed you to those answers).
 

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#15 ·
I past my smog test though it wasn't the smog I failed , there switching over my pinks to salvaged & in order to do that I had to get a break & light inspection which I failed & in order to pass the place that inspected my car said I had to get the abs light turned off & then they can pass me .
 
#19 ·
Buy the repair service on ebay from BBA, they regularly offer it for $99. Only buy new control unit, if they tell you that yours can't be repaired. When you send it for repairs you can remove it yourself and install it yourself. Since it's the same control unit no need for coding.
 
#22 ·
Only buy new control unit, if they tell you that yours can't be repaired.
I can understand the fear involved, so, one would buy a new unit, which is only about $450 plus coding; but what's wrong with a used unit from BBA or other reputable outfit if you get it at a good price and a guarantee?

Mine could not be rebuilt and I had to purchase a new one. It does happen.
Even then though, you don't have to buy a NEW unit. You can get a rebuilt unit from the same people who rebuild them. Same guarantee (AFAIK).

Realoem will not tell you if you have ASC or DSC. It gave me part numbers for both with my vin.
I know. I know. You can't dump everything on the OP at once.
You'll notice the canonical thread on the trifecta starts with me asking whether I have ASC or DSC (despite the DSC button staring me in the face on my dash!).

The best way to tell is to remove the ABS module and count the solenoid valves:
10 = ASC
12 = DSC
We should probably look for or start a thread on "how do I know if I have asc or dsc" where that information would be added.

That's the hardest way to check it. There are easier ways like checking the buildsheet, cabin button (asc/dsc), using a scanner and checking the p/n on the module.
Good information for a thread on ASC vs DSC
 
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