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ABS / brake lights "trifecta"

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If this only happens when very hot than you need either fixing yours or getting a new DSC unit. My understanding was that it happened first when hot and that issue has persisted since then hence the ABS pump troubleshooting suggestion - as the error persisted. If you are getting a new or buying someone else's used (only if cheap) then it has to be coded to your car. When you clear the errors do both appear immediately, even when cold? The thing is that you also have steering wheel sensor issue which would also trip off the ABS lights - if memory serves me...

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5 hours ago, dmarkovina1 said:

If this only happens when very hot than you need either fixing yours or getting a new DSC unit. My understanding was that it happened first when hot and that issue has persisted since then hence the ABS pump troubleshooting suggestion - as the error persisted. If you are getting a new or buying someone else's used (only if cheap) then it has to be coded to your car. When you clear the errors do both appear immediately, even when cold? The thing is that you also have steering wheel sensor issue which would also trip off the ABS lights - if memory serves me...

Only happens if car is already hot when I turn it on…

 

no other time.

 

if I leave it long enough to cool, the lights reset themselves on the next drive.

 

not sure about steering sensor, I reset that and that has stayed cleared since.

 

i’m exploring options of getting a s/h unit to test, and seeing if ECUTesting can repair what has been damaged on this one. - I don’t have much faith as they never found a problem in the first place!

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7 hours ago, dmarkovina1 said:

If this only happens when very hot than you need either fixing yours or getting a new DSC unit. My understanding was that it happened first when hot and that issue has persisted since then hence the ABS pump troubleshooting suggestion - as the error persisted. If you are getting a new or buying someone else's used (only if cheap) then it has to be coded to your car. When you clear the errors do both appear immediately, even when cold? The thing is that you also have steering wheel sensor issue which would also trip off the ABS lights - if memory serves me...

 

Only needs to be coded to the car if the numbers aren't the same IIRC

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Hoping Simon can sort me out with a 002 unit.

 

anyone know how to code the unit if I end up getting a different one? Can it be done with the usual programs? (Inpa / ncsexpert )

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My opinion is that even with the same part number it needs to be coded to the vin using ncs.  Then steering angle reset which is the other programme dis i think.

 

https://www.bimmerforums.com/forum/showthread.php?1765680-DIY-Code-used-E39-DSC-module-w-NCS-Expert

 

https://m.youtube.com/watch?v=ySNPwvJWWtk

 

I just fitted a good new old stock 02 module bought on ebay and it works fine.

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ABS sensors rarely fail and never all four. Good job as they corrode in and the allen bolt generally snaps off in the alloy hub. What joy they are.

 

The problem is heat soak from the engine. V8's are a bastard for it. A heat shield is a good starting place and good luck with a secondhand ABS ECU although the gamble is somewhat cheaper than the insane cost of a new one.

 

If this fault had a fixed pattern, I'd be wrapping it in wet towel or something - anything to keep it cool and see if the problem persists. 

 

Edit; all 002 DSC ECU's need coding regardless. It's the 001 ASC ones that are plug and play. 

 

 INPA is fine.

Edited by Sir Anthony Regents-Park

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Inpa will code the module to the vin.  Not so sure about the steering angle calibration unless you have a very early version.  Dis will do that.  Was in the links i sent.

Having changed my module a few weeks ago; the cheapest new i could find was euro car parts at about £400 for an 01.  However, they wanted £900 special order for a 002.  Possibly Schmeidmann could have been cheaper.  Was lucky and found a new old stock 002 on ebay.

From research the best repairer seems to be ECU testing.  BBA reman seemed to have mixed to poor reviews recently.  AC tronics also good but only accessible to the trade.

My module had been repaired before in the past.  Over ten years ago by ac tronics so i didn't want to risk a second repair.  If i had not found a new one i would have bought a second hand one for maybe £80 on ebay and got it worked over by ECU testing.  Problem with these modules i found was that it's not just the thin gold wires that get cooked but also the MOSFET power transistors.  Stupid price really for a fairly basic piece of electronics that has far less in it than an old mobile phone.

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It's a matter of opinion i guess.  I've had mine for 11 years longest I've ever kept a car.  Probably the best alround quality family car i have ever owned.  Had an F11 a while back as a hire car and preferred my car when i got back in.  My opinion is these can't be run easily on a shoestring as bangers.  Money has to be spent from time to time and they need to be kept on top of.  My e34 was a sorry wreck when i traded it for this car because i didn't do that.

My recent trifecta problem cost me £450 so not great but i hear of new cars with more electronics and more issues.

Edited by Dbcrd

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Another thing to look out for when diagnosing ABS sensor faults is the air gap between the trigger ring and the sensor. The ring itself corrodes and/or the metal the ring sits on rusts and swells expanding the ring, closing the air gap and damaging the sensor.

If this has happened, the easy fix is a new sensor and place a washer between the hub and the sensor where the hex bolt goes through bringing the sensor out a little more and re-creating the air gap. Most cars with ABS have a similar trigger ring system and

this is a money saving trick I learned years ago. I've seen trigger rings actually split due to rust swelling underneath it.

 

If the replacement ABS Module has the same part number it does not need coding to the car but you will have to clear the fault codes before a road test.

 

A steering angle sensor fault will only bring up the DSC light, not ABS, if only the DSC light comes on, a SAS re-set usually fixes it.

 

Hope this helps.

 

 

Edited by Busterbvi

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Like I mentioned before, I reset the steering fault and it hasn’t returned, so I don’t think that was anything to worry about. 
 

ECUTesting now have the unit back again because it got damaged when it was posted back.

 

I've also bought a complete pump/module off of @simongarland1987 just incase.

 

if I continue to have issues with the original unit once returned, I’ll swap the module over and see if anything changes.

 

if not, it might still be the pump (but I’m still suspecting the module)

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Had a phonecall from ECUTesting to say they now also need my pump so they can carry out further testing…

 

sounds a bit suspect, and like a lot more hassle because it means disconnecting brake lines etc.

 

I have a spare pump, should I just send them that?

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When you say pump, do you mean the actual housing next to engine which the ECU unit bolts to or the pre-charge pump next to the brake servo?  If it’s the former it’s straightforward to do but seal the ends of the brake pipes to prevent any moisture or leakage. And don’t press the brake pedal

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7 hours ago, dmarkovina1 said:

They understand that the fault is only apparent when the DSC unit is properly hot?

I have tried telling them this numerous times. 

 

im posting them the spare pump.

 

I’ll see what they say. If they still don’t find a fault, I’ll have it returned and send to ACTronics to get their opinion.

 

ive not been overly impressed with ECU Testing.

 

I’ll also try the spare module when I get a chance.
 

 

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8 hours ago, dmarkovina1 said:

You can test your pump with two wires...or post them the spare one, which means you will still be no smarter as to whether yours actually work...I would expect them to have their own test rig...

My pump works, or at least it does whilst the dash lights aren’t on… I have to admit, I’ve never tried heavy braking whilst the lights are lit.

 

when lights are cleared, I can stamp on the brakes and get the abs to activate.

 

one slight benefit is if I try everything else and still get the issue, I’ll have a tested pump to swap over when it goes into the garage.

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For whats it’s worth just had my unit back from them. No issues, was well

packed and it fixed the issues. They didn’t tell me what was wrong with it but looks like the pump and valve unit has been replaced and my original ECU repaired and fitted to the pump. 

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15 hours ago, Mashmanu said:

For whats it’s worth just had my unit back from them. No issues, was well

packed and it fixed the issues. They didn’t tell me what was wrong with it but looks like the pump and valve unit has been replaced and my original ECU repaired and fitted to the pump. 

Maybe I got the new guy, or the trainee, or it was a Friday afternoon etc.

 

I’ll progress with this plan and go from there.

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Sooo…

 

ECUTesting found nothing wrong whilst re-testing the module, and nothing wrong with the spare pump.

 

i’ve spoken to ACTronics who have also been recommended for these sort of issues.

 

They’ve said they can test the module on its own, but would prefer to test complete unit (incl pump) to be certain.

 

How much of a pain is it to remove the abs pump? And then bleed the system? - is it worth me replacing the two small flexi lines at the same time I do this?

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As I mentioned previously there is the main ABS unit (ECU, Valve body and pump) with 6 pipes going into it. This is easy to remove and in my own experience took about 5 minutes to remove. Ensure you seal the end of each pipe to prevent fluid leakage and moisture getting into the pipes/fluid. The precharge pump which is next to the brake servo under the in-car air filter I haven’t removed but would expect that to be very messy so lots of rags/tissue to soak up any fluid spillage and again seal the pipe ends. Refitting the main ABS unit was straightforward and yes you do need to bleed the brake system. You will need DIS or INPA to do the fronts as you need to use the pre-charge pump and actually DIS gets the ABS going too. 

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On 18/09/2021 at 16:12, Sir Anthony Regents-Park said:

ABS sensors rarely fail and never all four. Good job as they corrode in and the allen bolt generally snaps off in the alloy hub. What joy they are.

On 25/07/2021 at 21:20, d_a_n1979 said:

The UK sensors apparently are hard to remove as their small hex bolt corrodes and seizes

Are you refering to item 8 in this diagram?

https://www.realoem.com/bmw/enUS/showparts?id=DL82-EUR-02-2003-E39-BMW-530d&diagId=31_0255

Anyone know where you can buy these in the UK??

Part number is 07129901130 ISA screw M6X20-8.8-ZNNIV Chrome-free CR(VI)

Edited by ajl530d
Added more detail

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