ABS Issue (Brakes locking up) - Not common fault

[Leemarty6]

Had this resolved in the end! The ABS module has been removed previously and someone installed the connections in the wrong order! so the front was the back and visa versa cost me a fortune to get this figured out and the car now has a brand new ABS module...

Hi again, so the ECU Testing path didn't work for me either. They said that my unit couldn't be fixed (and it suffered transit damage as well).

When you tried the used unit and couldn't code it, do you remember what the issue was? I'm assuming the inverted connections problem was on the new unit.

We assume the new unit didn't have anything wrong with it in the end and that it could not be coded because the connections were incorrect but well never know.

During the processes the ECU was re-flashed which opened another can of worms. I had to get a replace ECU as well because the original got fried in the process.

I had the brand new ABS unit coded with the connections round the right way with a 2nd hand ECU. many £££ later.

I would say to source a second hand unit online that matches the part no. exactly and have a reputable mobile BMW coder give you a visit.

 

[andre.zammit]

Wow that's unfortunate to say the least... Hopefully we won't be comparing repair bills at the end of all this.

Yes I found a unit which matches my part exactly and the seller assured me that it can be re-coded.

It should arrive in a couple of days, maybe the story will stop there.

 

[srhutch]

Wow that's unfortunate to say the least... Hopefully we won't be comparing repair bills at the end of all this.

Yes I found a unit which matches my part exactly and the seller assured me that it can be re-coded.

It should arrive in a couple of days, maybe the story will stop there.

Coding these can be a bit of a bastard. I did mine last year as did another member on here. We shared data (think he helped me more though). He had tried a BMW indy who couldn't do it. I couldn't drive my car anywhere as I couldn't even bleed the brakes sufficiently to make driveable du to air in the pump.

Are you looking to code yourself or getting somebody to do it?

If you're going to try yourself I'm more than happy to try and help you through if I can.

 

[andre.zammit]

No a BMW specialist garage will install the part and code it. They use Autologic software for coding. What did you end up using?

The garage had a concern that sometimes parts which were not wiped of their old coding fail to be coded for another car.

 

[andre.zammit]

So I got the car back today and the issue is fixed!

Did a few tests of hard braking and now the ABS kicks in and no locking wheels!

If anyone comes by this thread in the future and has an E85/E86 Z4 which locks up a wheels under heavy braking, the ABS module is the issue. My brake pedal was going to the floor and wouldn't come back until the car was completely stationary (in a cloud of smoke from the locked up wheel).

 

[Alemito]

I’m having this issue too, but my rears unlock as soon as I release the pedal (luckily).
Still module?

 

[andre.zammit]

So the ABS never activates? I think it's strange that the rears lock up instead of the fronts though.

As the symptoms are not exactly the same I guess there is some hope that it's not the module.

 

[ph001]

Hey all, not been on here for a while. Guess what... gave the car a spruce up at the weekend and always take it up the road to dry the brakes off before garaging. Came back down the estate at about 25mph and pressed the brakes pretty hard. Brake pedal goes soft and rear brakes lock on solid! Massive rear skid until it came to a standstill at which point it released the brakes and all is well again!!!

No codes, no lights, nothing. Traction control and ABS all still seem to work just fine. The problem must happen when the EBC (Emergency brake control) kicks in. Extremely disconcerting and extremely dangerous!

My ABS unit went back to ECU Testing about 10 years ago so has the lifetime warranty on it... but that was just for the usual trifecta of ABS lights. Last thing I need right before Xmas :?

 

[andre.zammit]

Hi, that’s exactly what used to happen to me. I flat spotted a brand new tyre because of it.

I had my ABS unit replaced by a used one I got off eBay. Then I had to change the brushes in that to solve the trifecta issue that came with the used unit.

 

[ph001]

Hi, that’s exactly what used to happen to me. I flat spotted a brand new tyre because of it.

I had my ABS unit replaced by a used one I got off eBay. Then I had to change the brushes in that to solve the trifecta issue that came with the used unit.

Did you enquire if your existing one could be repaired by the likes of ECU testing?

I’m wondering if this is a more widespread problem than many if us realise but you wouldn’t know until EBC is activated (which could be quite rarely).

 

[ph001]

Hi, that’s exactly what used to happen to me. I flat spotted a brand new tyre because of it.

I had my ABS unit replaced by a used one I got off eBay. Then I had to change the brushes in that to solve the trifecta issue that came with the used unit.

Did you enquire if your existing one could be repaired by the likes of ECU testing?

I’m wondering if this is a more widespread problem than many of us realise but you wouldn’t know until EBC is activated (which could be quite rarely).

 

[ph001]

Hi, that’s exactly what used to happen to me. I flat spotted a brand new tyre because of it.

I had my ABS unit replaced by a used one I got off eBay. Then I had to change the brushes in that to solve the trifecta issue that came with the used unit.

Did you enquire if your existing one could be repaired by the likes of ECU testing?

I’m wondering if this is a more widespread problem than many of us realise but you wouldn’t know until EBC is activated (which could be quite rarely).

I can’t help thinking that something this dangerous should be a recall by BMW.

 

[andre.zammit]

I did send the unit to ECU Testing but it apparently got damaged during shipping (from Malta) and they said that it couldn't be fixed. This could have been either to the actual ABS issue or the damage (a part of its plastic cracked).

Anyway try your luck with ECU Testing anyway, if they can't fix it you won't be charged anything so I guess it's worth a try.

Re: "I can’t help thinking that something this dangerous should be a recall by BMW." yeah this is what kept me back from buying a brand new unit for thousands of pounds / euro. It would probably happen again in a few years as I don't think the unit was revised at all.

 

[ph001]

Hi all, please could someone have a quick look at their ABS unit to confirm if these connections look correct? It’s been like this for years but all the pics I can find on Google have the braided hoses at the top and bottom???

 

[ph001]

Anyone? :?

 

[andre.zammit]

These are from my car. I think they look the same as yours?

 

[ph001]

Thanks so much for that…. you can see that the top flexi hose (the one nearest the bulkhead) is in a different place on your car than it is on mine!

I can’t believe my car has been like this for years and only now has it come to light…. the previous owner must have connected it up wrong when the unit was sent to ECUtesting.

I’ll swap those top two connections over and report back.

 

[_Paclunch]

Thanks so much for that…. you can see that the top flexi hose (the one nearest the bulkhead) is in a different place on your car than it is on mine!

I can’t believe my car has been like this for years and only now has it come to light…. the previous owner must have connected it up wrong when the unit was sent to ECUtesting.

I’ll swap those top two connections over and report back.

Reviving this old thread. My rear right locks up when ABS kicks in and it doesn't release until vehicle speed is 0, even if I jump off the brake completely.

Looking at my ABS unit/pump I can see the pipes are orientated in a different order, with one of the flexi hoses being in the middle and not on the outer edges. Did the pipe swap work? I assume so, as if it didn't you probably would have returned to say! :lol:

 

[andre.zammit]

That’s exactly what used to happen to me with the rear wheel locking up.

I had to swap the module though. Hopefully fixing the pipe order works for you

 

[andre.zammit]

That’s exactly what used to happen to me with the rear wheel locking up.

I had to swap the module though. Hopefully fixing the pipe order works for you