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E39 speed sensor / abs issues!! help!

61K views 62 replies 16 participants last post by  528iAut  
#1 ·
Good morning all (as I assume its AM now in the US?) :),

I'm coming here for help because i've not had much luck on the bmw UK forums and hopefully this should be something quite trivial, but I just dont have much experience with bmw's.

So basically I was driving along the other day and my DSC, ABS and (!) lights, all yellow decided to come on and stay on. So i put it on the code reader I have and the error said:

Left front wheel speed sensor

So i thought, no problem thats a piece of cake. Bought the part, put it on and started the car, the lights were gone. Great I thought. Not even 200 meters down the road, I could feel the abs and dsc kicking in and interrupting my ride, I speeded up a little bit, they tried to cut in again, then all 3 lights just stayed on.

So i did a bit of investigating. Read the codes and the code now said:

Left front wheel speed sensor OR ABS Inlet valve

So I took my old sensor and put it on the right hand side of my car, just to make sure it was actually buggered, and it was, because when i read the codes again it said 'Right wheel speed sensor cable'.

And just to make sure, I put the new sensor in the side which is already OK (drivers side), and the error was gone, so the new sensor is fine.

So my question is, having replaced the sensor and now have working sensors, is it really possible for the ABS module just to die? I am assuming that the 'ABS Inlet valve' message means the module. Even when I clear the codes and drive, the ABS/Traction control seem very confused and cut in randomly!!

Any help is MUCH appreciated!
 
#2 ·
my DSC, ABS and (!) lights, all yellow decided to come on and stay on. So i put it on the code reader I have and the error said:Left front wheel speed sensor
Most of us have already been down the same road you have, despite the fact you're driving on the wrong side. :)

The code readers are notorious for giving the WRONG readings when the ABS is involved. Almost all of us (including myself) have seen the wheel sensor implicated when it was the ABS control module all along.

There are six ways to test the wheel speed sensors, none of which involve the code reader, and the simplest of which entails a five-minute under-the-hood wheels-on-the-ground test with a digital multimeter.

Yes it's wholly possible and quite common for the ABS to "just fail". Most of us get a few days' warning with intermittencies but eventually all of us get the dreaded three-finger salute (brake, abs, and dsc lights).

I assume that's what you have. If so, then my advice is for you to read this thread, from start to finish ... which I'll summarize in the three steps below:

STEP 1: Do the 5-minute DMM test of the 4 wheel sensors; if more than one test bad, you're probably doing the test wrong; if any one tests bad, then go to the step 2; otherwise go to step 3.

STEP 2: If any one sensor tests bad, doublecheck at the wheel after cleaning them off and checking the wires visibly. If it tests bad, replace it and go back to test 1. If it tests good, then go to step 3.

STEP 3: Rebuild the ABS.

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#3 ·
I cannot express my gratitude enough for your post, THANK YOU. I will get the ABS module rebuilt before returning the brand new sensor and test accordingly. I was almost certain it was the module.

If my old sensor turns out to be fine, i've saved myself ÂŁ90!!

Thanks so much!
 
#4 ·
I have an update:

I sent my ABS module off to BBA-Reman (on ebay) and they were unable to fix the module. They were very helpful and gave me a full refund just to add, but they told me that the error was on the control board itself which is sealed with a tamper-proof substance which they cant get to.

So basically i'm looking at getting myself a new module it seems... :(

I have a question though. Is it a good idea to get an after-market wheel sensor ? or do these have a bad reputation?
 
#5 ·
Is it a good idea to get an after-market wheel sensor ? or do these have a bad reputation?
From what I've read here, you want as close to stock for the wheel sensors as humanly possible (check the threads as it's a common topic).

To give back to the bimmerfest community, it would be great if you post post mortem pictures of your opened up ABS control module, especially shots of the inaccessible circuit board area.
 
#6 ·
#9 ·
Gents - this info is very helpful...I have the DSC light on with airbag and an intermittent check engine. Code for check engine says camshaft position sensor - yet no starting problems. Replaced front camshaft sensor - no change. Can't seem to find any other codes - was thinking I would try replacing the DSC and ABS relays to see what happens...anybody tried that before replacing the module? Thanks!
 
#10 ·
The camshaft sensor code is probably not related to your DSC light. What CPS do your codes point to? You replaced just one sensor, your other one may be bad.
 
#11 ·
Code reader didn't specify front or rear - my tech suggested the front as it is usually the culprit in his experience and is easiest to replace...guess I will replace the rear and see what happens. Thanks!

Any suggestions about the DSC light - no codes, but light is on along with airbag light...dealer wants $150 just to check, my indy tech says don't worry but it is the airbag light.
 
#12 ·
Unfortunately your DSC could be from any of your wheel speed sensors or the module. I'd check all of your speed sensor with a VOM.
 
#13 ·
I got the two finger salute today (ASC, ABS light) and I was extremely P.O'ed. One of those times where in the last month Ive spent $3000 on a transmission rebuild, and after deciding I wasnt going to sell the car for a while I dumped another $4-500 into sensors, water pump and tension struts.

Anyway, thanks Bluebee for your very through post on ABS failure modes (link above). I suspect my steering angle sensor is on the way out. After reading your post I turned the wheel slowly lock to lock and the lights went out. I'lll let you know if it comes back.
 
#15 · (Edited)
One month followup on the intermittant ABS/ASC light.

I was initially getting the two mentioned lights and they would go out either at random, or sometimes if I turned the wheel from lock to lock. This degraded in to the transmission not automatically shifting in to 3 or 4. If this happens, you can manually shift up by clicking the shifter from D to 3 and back to D. Downshifting is still automatic. Anyway, I thought initially it was the steering angle sensor because it could sometimes get it to go away by turning the wheel. I wanted to do the diode check on the wheel speed sensors using Bluebees thread http://www.bimmerfest.com/forums/showpost.php?p=4205801&postcount=48 but I have the older ABS System ('98 528) and the pin outs dont match up. I found this thread with the pin outs for the older ABS system: http://www.m3forum.net/m3forum/showthread.php?t=341672

Anyway, I changed out the left front sensor, which was literally crumbling apart. When tested, I got zero volts on the diode test and 3k ohms. It was supposd to be .5-2M ohms, according to the M3 thread. I cut the cable of the old sensor to do some further investigation and found that it had a small cut in the outer black insulation. The inner yellow/red wires were crumbling apart just touching them, and the copper was actually green from corrosion.

So as with all intermittent issues, it is fixed- until it isnt. The left front sensor was without a doubt bad, and I havnt had any errors since changing it out. I still dont see how the one sensor went from ABS/ASC error to then later include the transmission. Im keeping my fingers crossed.

This wheel speed sensor clearly gave its all and will receive full honors as it is laid to rest in the trash can.

Wires corroded 6" from the end of the sensor cable?
Image


Crappy pic showing the wheel sensor and not showing the two bolt holes for attachment because they crumbled apart when removed??
Image
 
#16 ·
One month followup on the intermittant ABS/ASC light.

I was initially getting the two mentioned lights and they would go out either at random, or sometimes if I turned the wheel from lock to lock. This degraded in to the transmission not automatically shifting in to 3 or 4. If this happens, you can manually shift up by clicking the shifter from D to 3. Downshifting is still automatic. Anyway, I thought initially it was the steering angle sensor because it could sometimes get it to go away by turning the wheel. I wanted to do the diode check on the wheel speed sensors using Bluebees thread http://www.bimmerfest.com/forums/showpost.php?p=4205801&postcount=48 but I have the older ABS System ('98 528) and the pin outs dont match up. I found this thread with the pin outs for the older ABS system: http://www.m3forum.net/m3forum/showthread.php?t=341672

Anyway, I changed out the left front sensor, which was literally crumbling apart. When tested, I got zero volts on the diode test and 3k ohms. It was supposd to be .5-2M ohms, according to the M3 thread. I cut the cable of the old sensor to do some further investigation and found that it had a small cut in the outer black insulation. The inner yellow/red wires were crumbling apart just touching them, and the copper was actually green from corrosion.

So as with all intermittent issues, it is fixed- until it isnt. The left front sensor was without a doubt bad, and I havnt had any errors since changing it out. I still dont see how the one sensor went from ABS/ASC error to then later include the transmission. Im keeping my fingers crossed.

This wheel speed sensor clearly gave its all and will receive full honors as it is laid to rest in the trash can.
If you google you'll find out that many transmission issues are caused by wheel speed sensors. Transmission needs that sensor information to do the shifting, if the transmission is now shifting smootly there is no reason to worry.
 
#20 ·
Hmmm... OK. The thread that Flybot quoted had listed both of them as a reference for the pinouts - so that's why I included them (assuming they were important). I didn't actually 'read' them, as it's mostly gibberish to me - so thanks for taking a look at it for us.
 
#22 · (Edited)
BTW, someone PM'd me a few times today from the E38 side asking about the pinout on the older ABS control modules.

Here's the content of that PM exchange today, so that others may benefit from the effort.

I have recently bought BMW 1998 740iL Sedan E38. I have problems with ABS Module & Wheel Sensor. I read your post http://www.bimmerfest.com/forums/sho...1&postcount=48 but I have different ABS Connector it has 15 holes. Where can I find which hole are for which wheel sensor? I don't know which connector should I test. one connected to ABS? or one behind glove box (ABS/ASC computer connector) describe in http://www.bimmerfest.com/forums/sho...&postcount=645. My model is E38 I hope if I will take glove box out it wont turn out there are different connections.

here is how my connector looks like:
Image
My answer was as follows:
I think everything you need is already in the referenced thread.
Remember, 200,000 people (views anyway) have visited that thread, and there are about 650 posts - all containing great information and lots of photos and diagrams.
So - by now - almost all the possible questions have been asked and answered already.
For example, this is the same 15-pin connector you have which was already shown long ago in post #498
http://www.bimmerfest.com/forums/sho...&postcount=498
Image


But more importantly, you should scroll to post #333 which shows in detail the right connectors for your style of ABS control module setup:
http://www.bimmerfest.com/forums/sho...&postcount=333

Image


More information is in post 341
http://www.bimmerfest.com/forums/sho...&postcount=341

And, more information is in the next half dozen posts after that.
Image

Image
Hope this helps but it's best to post your question to the forum and not in a PM simply because that will help others also.
Good luck.
 
#23 ·
I'll "spoon-feed" you to save you much reading. Do not replace anything else except your module. Or, you can try getting it rebuilt by BBA here in US. Re-build saves you having to recode, but do not lose sight of the age of your module which means it has greater chance of another connection failing. There was a post here showing how a module is re-built and believe company was in UK. They seem to replace all wires and resolder and not just the offending connection. Your module would then be as good as new practically.
 
#28 ·
My issue with the ABS/ASC is fixed, as posted above, which did not include blindly replacing/rebuilding my ABS module. Your "help" is late, incorrect, and not very helpful. I normally avoid responses to rubbish, but today is just one of those days.
 
#30 ·
I'm sorry there was a misunderstanding. Maybe my post precipitated it, and, if so, I apologize.

540iman has been instrumental in giving us the DMM test and the pinout for the newer E39s, so we can run the diode test on the hall-effect sensors. It's simply amazing that we even HAVE a test for the sensors, because all the tests I know of for the ABS control module are complicated, and fraught with red herrings.

Likewise, Flybot has been instrumental in pointing us to a thread (which I had not known about) which shows the same test for the older E39s - but with a different pinout. This is great additional information.

I, for my part, took the information from both of you and combined it as best I could and made the references available to everyone else via the bestlinks and a summary post above (and to the canonical ABS trifecta thread).

So, the good news is that, together, we're a well-honed team.

99% of what I write is for the benefit of the next person - and I take the great information YOU GUYS give me - and put it together for them.

Thanks & kudos to BOTH Flybot and 540iman!
 
#31 ·
I was driving my BMW 520i SE manufactured 2000 today and without any warning, the speedo stopped, the ABS and ASC light lite up on the dash and the fuel flow meter on the dash stopped working, the tripometer doesnt clock any miles up now either. I called out the AA mechanic who believes its a speed sensor on the wheel but would that of isolated all those dials, i have now booked the vehicle into BMW for a service check on that issue as the car only had a full service 500 miles ago and a MOT in february. Does the diagnostic check sound familiar to anyone and is it a expensive job , help please
 
#32 ·
I would cancel the stealer appt., remove ABS module, and send to BBA for attempt at rebuild. You can drive car while module is out. BMW will say there is no way they can predict when a module will go out even if it were 10 miles after you left the stealer.
Could it be a speed sensor? Maybe, but doubt it due to number of things that went wrong at once. Sounds like module to me and at 12 years plus, you need it looked at anyway. Dealer will quote you $2000- you watch and see...
 
#33 ·
BMW 520i se

Hoyya thank you for the info, best check my bank balance by the sounds of it, hopefully it may be a quick fix but as you say with so many items failing in one go it sounds bad. The car still runs OK but its nice having everything working. I will check out the speed sensor and see if i can find any obvious faults with it, BMW waiting list for service is nearly 2 weeks, not good for a quick fix. May approach a local garage and see what happens, thank you again for some direction, at least my GPS will let me know my speed in the meantime:)
 
#34 ·
BMW 520i se

Hiyya thank you for the info, best check my bank balance by the sounds of it, hopefully it may be a quick fix but as you say with so many items failing in one go it sounds bad. The car still runs OK but its nice having everything working. I will check out the speed sensor and see if i can find any obvious faults with it, BMW waiting list for service is nearly 2 weeks, not good for a quick fix. May approach a local garage and see what happens, thank you again for some direction, at least my GPS will let me know my speed in the meantime:)
 
#35 ·
You will find better knowledge here than BMW will give you or most indys-not all, but most.
You can do it! Pull the ABS module (remove one big plug and 6 screws and mail it off.
Look on Ebay for an auction repairing BMW ABS. See if you can find an auction for BBA to do the work. About $100 bucks for a re-build or nothing if yours can't be re-built. INDYs don't use re-builders nor do stealers as it just takes the money you have that they want. If you are going to own a BMW, you best get comfortable working on it. Read the many threads.
 
#37 ·
Just did another check on my car, going by info on this forum, when started from cold, warning lights out but no speedo or fuel swing meter, sounds like it could be that ABS computer but will double check it again in the morning to confirm. thank you to date for all the info, i would of been lost without it
 
#38 ·
E39 TDS ABS pre 98 Touring - Don't use KOED ABS sensors.

Sorry for not reading the answers in this tread, and I think I have a different car. But here in Scandinavia we get cheaper E39 parts from KOED. Generally O.K. But not for the ABS sensors (which differs before and after 98). For those I had to use the original BMW ones (or second hand ones from the scrap yard). The KOED ones works for a while, and gradually ceases. And gives the initially described problems. The original ones, for one year now, still just fine.
 
#39 ·
Sorry for not reading the answers in this tread, and I think I have a different car. But here in Scandinavia we get cheaper E39 parts from KOED. Generally O.K. But not for the ABS sensors (which differs before and after 98). For those I had to use the original BMW ones (or second hand ones from the scrap yard). The KOED ones works for a while, and gradually ceases. And gives the initially described problems. The original ones, for one year now, still just fine.
When you buy sensors for BMW I would only buy OE or OEM sensors. Some aftermarket sensors might work, but I don't want to be a guinea pig.