ABS Issue (Brakes locking up) - Not common fault

wonkydonkey · Post by **wonkydonkey** » Fri May 24, 2019 11:19 pm

Example of repair service: https://www.ecutesting.com/product-cata ... amc916203/

andre.zammit · Post by **andre.zammit** » Thu Apr 30, 2020 9:30 am

Leemarty6 wrote: ↑Fri May 24, 2019 10:58 pm So I bought a used abs from a French supplier £800.
Fitted programmed and now the DSC won’t calibrate. Now it’s getting pricey..

I’m looking at a new ABS module and pump from BMW for just shy of 2K with a 7.5% discount. Must return the one from my car to qualify.

All I can do is hope now that this resolved the issue as I’m literally throwing money at it.

If anyone’s got any suggestions will be appreciated!

My garage indicated that no physical component would lock the brakes on, so it must be an ABS fault

Hi, I have the exact same issue with my Z4. Where you able to fix this issue?

I'm tempted to send my ABS module in for a rebuild but as there are not fault codes reported from it I'm not sure this is the way to go.

Leemarty6 · Post by **Leemarty6** » Tue May 05, 2020 3:54 pm

andre.zammit wrote: ↑Thu Apr 30, 2020 9:30 am
Leemarty6 wrote: ↑Fri May 24, 2019 10:58 pm So I bought a used abs from a French supplier £800.
Fitted programmed and now the DSC won’t calibrate. Now it’s getting pricey..

I’m looking at a new ABS module and pump from BMW for just shy of 2K with a 7.5% discount. Must return the one from my car to qualify.

All I can do is hope now that this resolved the issue as I’m literally throwing money at it.

If anyone’s got any suggestions will be appreciated!

My garage indicated that no physical component would lock the brakes on, so it must be an ABS fault
Hi, I have the exact same issue with my Z4. Where you able to fix this issue?

I'm tempted to send my ABS module in for a rebuild but as there are not fault codes reported from it I'm not sure this is the way to go.

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...

andre.zammit · Post by **andre.zammit** » Tue May 05, 2020 6:03 pm

Glad to hear that! (apart from the costing you a fortune part)

I just sent mine for repair so hopefully I won't need to go through all the hassle of coding a new one.

At least reading your reply gave me a bit of encouragement that the ABS module seems to be the culprit.

andre.zammit · Post by **andre.zammit** » Mon May 11, 2020 4:32 pm

Leemarty6 wrote: ↑Tue May 05, 2020 3:54 pm 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.

Leemarty6 · Post by **Leemarty6** » Tue May 12, 2020 2:19 pm

andre.zammit wrote: ↑Mon May 11, 2020 4:32 pm
Leemarty6 wrote: ↑Tue May 05, 2020 3:54 pm 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 · Post by **andre.zammit** » Tue May 12, 2020 2:51 pm

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.

Post by **srhutch** » Tue May 12, 2020 5:21 pm

andre.zammit wrote: ↑Tue May 12, 2020 2:51 pm 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 · Post by **andre.zammit** » Tue May 12, 2020 5:42 pm

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 · Post by **andre.zammit** » Mon May 18, 2020 6:30 pm

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 · Post by **Alemito** » Tue Oct 20, 2020 7:19 pm

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

andre.zammit · Post by **andre.zammit** » Tue Oct 20, 2020 9:04 pm

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 · Post by **ph001** » Tue Dec 06, 2022 7:05 pm

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 · Post by **andre.zammit** » Wed Dec 07, 2022 12:22 am

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 · Post by **ph001** » Fri Dec 09, 2022 6:00 am

andre.zammit wrote: ↑Wed Dec 07, 2022 12:22 am 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).

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