ABS and traction control lights on the dash - looking for an answer to the mystery!

[Little Lady Katie]

Hi guys and girls,

Hope everyone’s having a great weekend, and those of us in the uk enjoying this AMAZING heatwave!

So I have a problem with my beautiful baby, a 2000 3.0 z3 roadster, and I’m looking for some help/advice/thoughts on this one!

To give a bit of context and background to the story....

I had my airbag light come in a month or so ago. It’s registering as the positive battery cable (SBK cable) and I’ve been so lucky in having the fantastic help and support of another member on here, @mrscalex , in tackling that. We are hopefully fitting a replacement soon. I’m only mentioning that because I don’t know if it bears any relevance/is linked to this new fault.

So the problem I’m seeking help on first occurred yesterday. I stared the car up for the second time in the day and my ABS and traction control lights were both on. My heart sank! This is not a new thing for me; I’ve had the standard wheel speed sensor faults and things like that before, and all those times I’ve the past a code has registered and I’ve gotten to the bottom of the problem and changed the sensor. Strangely though, no codes registered at all with these. I have a really good code reader (ex garage/mechanics one) that reads under the steering column and a cheaper one that I use to read the airbag codes from the engine. Neither registered any codes (other than the airbag one I know I have linked to the problem with the SBK cable)

The car was driving as normal. No crunching of ABS which I’ve had before when I had a fault with one of the wheel speed sensors. The lights both went off 5 mins into the drive.

This repeated on a drive later that day. Lights came on when I started the car up and went off after 5 mins. Again no codes.

Today I started up the car and heart sank as the dreaded 2 lights came on again. Once again no codes, but this time they stayed on for the full drive

I’ve asked a good friend and fellow zedder @Aceman and he’s leaning towards thinking it might be something to do with Mmm not sure but you are probably right in thinking the extremes heat at the moment may have something to do with the abs module as he says they do suffer from bad solder joints on the circuit board, which he explained you can either repair or replace the unit but that also involves recoding in the replacement which is a pain.

We thought it would be a good idea to put the question to the forum and ask if anyone else has any thoughts or ideas or indeed any of their own experiences of this?

Would it be worth taking it to a specialist bmw diagnostics place to see if they could read a bit deeper into the electronics? (I do have one up the road from me which is run by a couple of bmw master technicians who are good and have the software and know how for it, but do charge accordingly!!) or is it something I could potentially fix with the help of another member?

Thank you so much in advance everyone!!!!

 

[D R Oldfield]

I have a similar issue with my 1998 2.8 z3 the abs and traction control light has come there are no codes and the asc switch doesn't do anything the abs does seem to work I have been told it's probably a wiring fault

 

[the Nefyn cat]

Wouldn't have thought that having a code-reader plugged in would cost a vast amount, even if it's a really fancy one. Only a few minutes work, and no need to get dirty, even. Got to be cheaper than trying to sort it some other way, seen too many people throw loads of bits at a car rather than get some proper diagnosis done.

 

[Little Lady Katie]

Wouldn't have thought that having a code-reader plugged in would cost a vast amount, even if it's a really fancy one. Only a few minutes work, and no need to get dirty, even. Got to be cheaper than trying to sort it some other way, seen too many people throw loads of bits at a car rather than get some proper diagnosis done.

I absolutely agree! I’ve had two code readers plugged in! One under the steering column and one directly off the engine to no avail. They’re not registering any codes being thrown up

I just wondered if any others had any advice/experiences of this, and am contemplating as a next step taking it to autohaus for some more specialist bmw diagnostics

 

[the Nefyn cat]

If the blokes up the road have specialist BMW gear they may find something that a generic code reader can't. Not saying they definitely can, but sometimes there's a reason why some things cost more than others. I've got a cheapo code reader myself, but if anything complicated starts to rear its ugly head then the laptop comes out and INPA gets used. And a quick plug-in shouldn't cost that much.

 

[Sean d]

Mine is doing the same since its been stripped and new sensors fitted, however its not been on a run yet, only did 100 yards in it and hoped it would clear, failing that the fuse will be removed

 

[NZ00Z3]

You need to read the ABS codes from the round connector under the bonnet. All computers are available there.

The OBDII plug under the steering column only connects with the DME.

 

[Little Lady Katie]

Ive tried reading from under the steering column and with a different code reader which connects under the bonnet. It’s just not picking anything up

Next step definitely would be to take it to autohaus - it’s run by a couple of bmw master technicians and they’re bloody good and they have the expert kit, I just wanted to seek some advice from other z3 owners first just to see if I could glean any other advice and info on the topic, especially because autohaus aren’t cheap (they get to the bottom of things, but understandably you pay a premium. And I don’t start my first dr job for 3 weeks and won’t get my first paycheck for 8!) . Lights have gone off again and once again no codes being thrown and car is driving as normal. Definitely none of the ABS crunching I got last time I had a wheel speed sensor go awry and trigger that dash light to come on. It’s very strange

 

[Little Lady Katie]

Thank you so much all

 

[Little Lady Katie]

I have a similar issue with my 1998 2.8 z3 the abs and traction control light has come there are no codes and the asc switch doesn't do anything the abs does seem to work I have been told it's probably a wiring fault

Does sound very similar!!

 

[Sean d]

Ive tried reading from under the steering column and with a different code reader which connects under the bonnet. It’s just not picking anything up

Next step definitely would be to take it to autohaus - it’s run by a couple of bmw master technicians and they’re bloody good and they have the expert kit, I just wanted to seek some advice from other z3 owners first just to see if I could glean any other advice and info on the topic, especially because autohaus aren’t cheap (they get to the bottom of things, but understandably you pay a premium. And I don’t start my first dr job for 3 weeks and won’t get my first paycheck for 8!) . Lights have gone off again and once again no codes being thrown and car is driving as normal. Definitely none of the ABS crunching I got last time I had a wheel speed sensor go awry and trigger that dash light to come on. It’s very strange

It may well be just a dirty sensor

 

[Little Lady Katie]

It may well be just a dirty sensor

It’s definitely a possibility isn’t it. Were you thinking possibly a wheel speed sensor, or could there be another/others to consider?

Thanks

 

[roadvoyager1]

This topic was subject of a few threads a couple of years ago. I had a similar intermittent problem on my 1999 2.8
This was probably the most useful thread (read later as it is quite long) https://zroadster.org/threads/abs-asc.12579/page-5#post-216997
Picking up on your story so far. The socket under the steering column does not access all of the modules and this is likely to be why you are not getting codes. The round plug under the bonnet gives access to all modules if you have the correct diagnostics tool. BMW INPA software is suitable. Several members have this, is there anybody in the York area who can help with INPA? I have it but am about 80 miles from you and am sure there will be somebody more local.
Depending on the code you get you can decide what is required next. If it is a module fault it can be repaired or replaced, and recoding which you mention is a simple process with INPA taking all of 5 minutes.
It could be the high temperatures are causing a latent fault to show up and it will go dormant when temperatures reduce.
Please come back and ask for help or further advice. Even the best auto techs seem to struggle with this type of fault and we would much rather help you solve the problem than see you go down the " specialist" misdiaglosis route.
Okay, get a cup of tea and settle down for a read of that thread.

 

[Geophys]

I recently left mine with the boot not quite shut properly and a week or so later went to start and the battery had gone completely flat, it would operate the central locking but when you turn the key no lights at all. Well I charged it up for 24hrs and it fired up just fine but the traction control light stayed on as did the brake hydraulics light. I though I'd take it for a quite drive for a bit and see if they went out, half an hour later still on, the brakes seemed to be fine, but I had been driving fairly carefully. Arrived back at my road, which was deserted, so charged up to the house and really slammed on the brakes, immediately both lights went out and have been off ever since. The only thing that could have caused the problem was electrical supply to the sensors, which just needed really waking up.

So I would wager that your problem could certainly be an electrical supply one, so my second act would be to get the continuity of the wiring checked (Full codes being read, the first act.)

 

[D R Oldfield]

Hi does anyone have a wiring diagram of that abs system, which fuses feed it and we're abouts is the abs control module
Thanks in advance

 

[Brian H]

Would it be worth taking it to a specialist bmw diagnostics place to see if they could read a bit deeper into the electronics? (I do have one up the road from me which is run by a couple of bmw master technicians who are good and have the software and know how for it, but do charge accordingly!!) or is it something I could potentially fix with the help of another member?

The code readers you have will pick up the same codes as the master technicians, as there are no codes stored there is no info to diagnose, did your code reader manage connect to the ABS unit? We have seen a number of pumps fail over the past few years and this could be one area to investigate?

 

[Mario]

It’s definitely a possibility isn’t it. Were you thinking possibly a wheel speed sensor, or could there be another/others to consider?

Thanks

Hello I have the same car that you have a 3.0 and I have successfully fixed mine, I have the INPA/DIS cable and software and I have done lots of troubleshooting, I am a bit far from York in North London but if you fancy a drive here I can give it a go and hopefully fix it, I have replacement sensors for everything since I bought lots of parts when troubleshooting mine. In my case I had problems first with the wheel speed sensors, but after that a little known fact is DSC cars have sensors under the passenger seat that go bad if they get wet which is possible even if you have had the smallest water leak as they seat right at the bottom and are covered by thick insulation foam.

 

[mrscalex]

Katie’s car is an older 3.0 so may not have the DSC. Or they may all have it. Can’t remember.

I’m probably catching up with Katie over the next few days when we’re on hols that way. So I’ll take my laptop with me.

Katie stay on my case to pack the laptop and arrange to meet!

 

[Mario]

Mine is one of the early 3.0s but you might be right it might have ASC or something else. Let us know how it goes!

 

[Little Lady Katie]

This topic was subject of a few threads a couple of years ago. I had a similar intermittent problem on my 1999 2.8
This was probably the most useful thread (read later as it is quite long) https://zroadster.org/threads/abs-asc.12579/page-5#post-216997
Picking up on your story so far. The socket under the steering column does not access all of the modules and this is likely to be why you are not getting codes. The round plug under the bonnet gives access to all modules if you have the correct diagnostics tool. BMW INPA software is suitable. Several members have this, is there anybody in the York area who can help with INPA? I have it but am about 80 miles from you and am sure there will be somebody more local.
Depending on the code you get you can decide what is required next. If it is a module fault it can be repaired or replaced, and recoding which you mention is a simple process with INPA taking all of 5 minutes.
It could be the high temperatures are causing a latent fault to show up and it will go dormant when temperatures reduce.
Please come back and ask for help or further advice. Even the best auto techs seem to struggle with this type of fault and we would much rather help you solve the problem than see you go down the " specialist" misdiaglosis route.
Okay, get a cup of tea and settle down for a read of that thread.

Thank you for this! I am about to sit down and read now (apologies for delay in Response - it’s been my graduation week and to say it’s been hectic is a gross understatement. Also trying to get all the paperwork sorted for starting my first dr job in 10 days time which is frankly pretty terrifying!!) the lights haven’t come on again for the past 3-4 days and I’m just hoping they’ll stay off (that’s optimistic me talking) but more realistic me is wondering If I need to consider that there might be something more underlying this