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FAQ - Traction Control Errors / Random braking / Instability Problems / ABS & DTC Issues

128K views 138 replies 43 participants last post by  Adam72 
#1 ·
The issue: Traction Control Errors / Random braking / Instability Problems / Cruise Control issues / ABS & DTC Issues / Jerky Power Restrictions / Erroneous Flat Tyre Warnings. Symptoms commonly starts as TC intervention during left or right hand bends, then on straights, then near constantly.

Diagnosis: Turn all your traction control nannies off my holding the DTC button for around 5 seconds, then re-test your car carefully. We don't advise trying this test in slippery/dangerous conditions for obvious reasons! If your rings are bad enough, they may also throw a 'Wheel speed sensor rear extrapolation' error. You can also check the wheel speed sensors via live monitoring of the wheel speed sensor outputs using a laptop and BMW software or similar. You won't get any errors when stationary annoyingly.

The usual cause: Rusty rear driveshafts. The driveshafts corrode, and the rust causes the Reluctor ring/s to expand, and sometimes crack too. If the ring expands enough, it will make contact with the wheel speed (ABS) sensor. Here's a good photo courtesy of Teasdas, note the crack and shiny area (witness of contact):



Solution: Basically you need a new reluctor ring, and most probably a new ABS sensors too. No coding required. Reluctor rings are available from eBay for around £5.



Method (courtesy of dozydoog):

The hub nut (Number 4 in the image below) should not be an issue, it' simply a 30mm or 32mm socket job but the nut is staked to the grooves in the end of the drive shaft, these need knocking out before you wind the nut off to avoid thread damage. Breaker bar makes easy work of the factory 190nm if someone applies footbrake with engine running

The splines will be tight, wind nut off about 3mm then find a bar that fits inside the nut and apply a solid whack with a lump hammer. please dont hit the nut or the driveshaft end with the nut removed, you will cause damage, mine went with the first solid blow. needs a new nut on re-assembly. If it's really stuck, soak with 'Plus Gas', leave overnight and retry in the morning. Never be tempted to strike the end of the M24 shaft, you'll peen it over and wreck the thread. If you have to, use a plastic / hide or other soft hammer.

Once the drive shaft has moved tighten it back into original position but only to low torque



To split the driveshaft, the 6 drive shaft to axle torx bolts (Numbered 3 in the image above) have to be removed with care, do not damage the inner cv joint gaitors. You will need a assistant to lock the wheel in various position with a bar placed across 2 replaced wheel studs as you need to rotate the shaft to get at each bolt in turn.

Shaft should now compress and clear the diff casing. The issue is on the nearside where rear 2 exhaust mounts need to be eased off to allow the shaft to clear the diff, once done the shaft can be knocked from the hub a 2nd time, much easier.

Ok, on mine the amount of rust under the ring had expaned it by at least 1mm. quick crack cross the ring with a chisel and it's off.
by the time the rust was chipped off, wire brushed, filed off and emery'd i'd guess there was .25mm clearance with the new , we had to use epoxy as loctite would not have done.

reverse for putting back together, but again, mind the drive shaft gaitors. getting enough thread showing through the hub to engage the nut will be a problem, ensure everything is cleaned and lightly oiled then tap with a soft hammer on the inner face of the drive shaft until the threads can be accessed.

E Driveshaft male torx bolts vary with car model:
M8 bolts - 52Nm
M10 bolts - 80Nm

(drivers side is much simpler due to no exhaust)

Whole job about 1 1/2 hours for an old git like me and in total for both sides was £13, £4 each reluctor ring and £5 for the epoxy as had run out.

An alternative to glue-on rings are the heat-on variety, see here for a tutorial:



It's good practice to replace the 6 driveshaft bolts and hub nut, parts available from Cotswold BMW or your local friendly parts counter. Just give them the last 7 digits of your VIN to ensure you get the correct parts for your car.

Alternative fixes: If you don't fancy gluing a new ring on to your old shaft, you can buy a replacement pattern drive-shaft for around £100 from various motor-factors.

Disclaimer: This FAQ post is intended to be as balanced and accurate as possible, but this thread should be considered as opinion only. We can not be held responsible for injury, damage or expense caused.
 
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#2 ·
This has been really written at the right time, thanks marco_polo!
Some weeks ago I had the intermittent Traction Control warning light coming off and cutting down my engine / braking on a straight, non slippery stretch of motorway road at constant speed.
Never happened again till the day before yesterday, when it is showing up quite frequently.

I can imagine it means that the reluctor ring has expanded quite much now and it is frequently touching the ABS sensor.

Being very lucky, I actually brought the car to the garage literally last week and I can't be bothered to take it down again, seeing also as we have planned an appointment two months down the line to replace anyway the brake pads; I reckon all this could be tackled there and then, but I have some questions:
- is disabling the DSC and DTC going to compromise the ABS intervention? I doubt so but would like a confirmation
- can the continuous expansion of the reluctor ring permanently ruin or temporarily hinder the ABS capability to understand there is a need to intervene?
- overall, understanding the risks of driving with DSC and DTC disabled, is this something that needs attention asap or you reckon can wait 2 months? (I drive approximately 1500 miles per month).
Thanks!
 
#3 ·
Disabling the DTC doesn't disable ABS braking, but dodgy wheel speed sensors to compromise the ABS function as it's getting erroneous signals. It will return to normal/safe condition once the rings and sensors are repaired, no permanent damage/memory.

I'd want them done reasonably quickly. An insurance company might argue the car isn't in a roadworthy state with defective ABS/DTC, why give them any wiggle room!
 
#4 ·
so In essence, disabling the DTC gets rid of the annoyance of the car slowing down randomly, ABS is still working per se but because the sensors are anyway screwed up, could compromise the ABS functionality for the moment being?

I totally understand that a car is unsafer without the ABS/DTC, but if I were to drive a Renault Clio of the year 1998 i would probably be in the same situation (w/o ABS, traction control etcetc.)
 
#5 ·
No ABS could be safer than malfunctioning ABS though? The car will be releasing the brakes when it shouldn't, that could actually make the car less stable than a nice old (skidding) Clio? Not sure I'd want the car thinking just one wheel has locked up, effectively disabling that calliper?

Up to you though, none of my business. :)
 
#7 ·
Hi, recently got myself an 07 plate E87 and I've found that I'm having the same issues as those mentioned above, I've drove it round this week with the DSC/DTC all disabled and found it stops the random breaking etc but obviously I don't wish to be driving round like this forever, could this cause CCID-24, 42 & 50 (DBC Brake Assist Failure, Brake and Driving Control Failure & Tyre Monitoring Failure) to all show up?
 
#8 ·
msmith96 said:
Hi, recently got myself an 07 plate E87 and I've found that I'm having the same issues as those mentioned above, I've drove it round this week with the DSC/DTC all disabled and found it stops the random breaking etc but obviously I don't wish to be driving round like this forever, could this cause CCID-24, 42 & 50 (DBC Brake Assist Failure, Brake and Driving Control Failure & Tyre Monitoring Failure) to all show up?
Yes.

The Tyre Pressure Monitoring System works via the wheel speed sensors and reluctor rings. Basically, the TPMS expects all the wheels to rotate at roughly the same speeds. If one wheel suddenly becomes smaller in diameter (puncture), it will rotate faster than the others, which gets detected and flagged on the dash. If the TPMS isn't getting sensible readings from the wheel speed sensors it will throw CC-ID 50.

24 and 42 are obviously easily connected to the wheel speed sensors / reluctor rings.
 
#9 ·
I have this problem and I've checked the reluctors rings which look good and nothing is rubbing on the sensors,
Atm I'm driving with the dtc switched off which isn't ideal in wet weather,any ideas what else it could be?
 
#12 ·
Kittybmw said:
Yeah it's ok when it's off
Yours will be the first of over a hundred cars which isn't reluctor ring/abs sensor related, how weird. I'd definitely remove the sensors from the car and inspect them yourself, just to completely rule them out as the source of your problems. Check their wiring and connectors too.
 
#13 ·
marco_polo said:
The issue: Traction Control Errors / Random braking / Instability Problems / Cruise Control issues / ABS & DTC Issues / Jerky Power Restrictions. Symptoms commonly starts as TC intervention during left or right hand bends, then on straights, then near constantly.

Diagnosis: Turn all your traction control nannies off my holding the DTC button for around 5 seconds, then re-test your car carefully. We don't advise trying this test in slippery/dangerous conditions for obvious reasons! If your rings are bad enough, they may also throw a 'Wheel speed sensor rear extrapolation' error. You can also check the wheel speed sensors via live monitoring of the wheel speed sensor outputs using a laptop and BMW software or similar.

The usual cause: Rusty rear driveshafts. The driveshafts corrode, and the rust causes the Reluctor/s ring to expand, and sometimes crack too. If the ring expands enough, it will make contact with the wheel speed (ABS) sensor. Here's a good photo courtesy of Teasdas, note the crack and shiny area (witness of contact):



Solution: Basically you need a new reluctor ring, and most probably a new ABS sensors too. No coding required. Reluctor rings are available from eBay for around £5.



Method (courtesy of dozydoog):

The hub nut (Number 4 in the image below) should not be an issue, it' simply a 30mm or 32mm socket job but the nut is staked to the grooves in the end of the drive shaft, these need knocking out before you wind the nut off to avoid thread damage. Breaker bar makes easy work of the factory 190nm if someone applies footbrake with engine running

The splines will be tight, wind nut off about 3mm then find a bar that fits inside the nut and apply a solid whack with a lump hammer. please dont hit the nut or the driveshaft end with the nut removed, you will cause damage, mine went with the first solid blow. needs a new nut on re-assembly. If it's really stuck, soak with 'Plus Gas', leave overnight and retry in the morning. Never be tempted to strike the end of the M24 shaft, you'll peen it over and wreck the thread. If you have to, use a plastic / hide or other soft hammer.

Once the drive shaft has moved tighten it back into original position but only to low torque



To split the driveshaft, the 6 drive shaft to axle torx bolts (Numbered 3 in the image above) have to be removed with care, do not damage the inner cv joint gaitors. You will need a assistant to lock the wheel in various position with a bar placed across 2 replaced wheel studs as you need to rotate the shaft to get at each bolt in turn.

Shaft should now compress and clear the diff casing. The issue is on the nearside where rear 2 exhaust mounts need to be eased off to allow the shaft to clear the diff, once done the shaft can be knocked from the hub a 2nd time, much easier.

Ok, on mine the amount of rust under the ring had expaned it by at least 1mm. quick crack cross the ring with a chisel and it's off.
by the time the rust was chipped off, ire brushed, filed off and emery'd i'd guess there was .25mm clearance with the new , we had to use epoxy as loctite would not have done.

reverse for putting back together, but again, mind the drive shaft gaitors. getting enough thread showing through the hub to engage the nut will be a problem, ensure everything is cleaned and lightly oiled then tap with a soft hammer on the inner face of the drive shaft until the threads can be accessed.

E Driveshaft male torx bolts vary with car model:
M8 bolts - 52Nm
M10 bolts - 80Nm

(drivers side is much simpler due to no exhaust)

Whole job about 1 1/2 hours for an old git like me and in total for both sides was £13, £4 each reluctor ring and £5 for the epoxy as had run out.

An alternative to glue-on rings are the heat-on variety, see here for a turotial:



It's good practice to replace the 6 driveshaft bolts and hub nut, parts available from Cotswold BMW or your local friendly parts counter. Just give them the last 7 digits of your VIN to ensure you get the correct parts for your car.

Alternative fixes: If you don't fancy gluing a new ring on to your old shaft, you can buy a replacement pattern drive-shaft for around £100 from various motor-factors.

Disclaimer: This FAQ post is intended to be as balanced and accurate as possible, but this thread should be considered as opinion only. We can not be held responsible for injury, damage or expense caused.
Hi Marco

Helpful as always, is there an uprated driveshaft option?
I saw something the other (trying to find link atm), I think it was for a 135i but could be wrong.

Thanks
 
#16 ·
So finally managed to have a look and found it's the n/s ,the reluctor looks ok but something was definitely rubbing on the sensor,I put a washer inbetween the sensor and the housing to pull it out a mm and it drove fine so will be sorting it in the near future, the for your help on this Marco 👍
 
#17 ·
Hi Guys,

Been a while since I've been on and posted anything but it would seem that I am the latest one to be having these DTC/ABS errors on my car.

Started yesterday when all of a sudden a warning came up on the dash and the drive showing an ABS warning, Driving Stability warning, DBC failure, FTM system error and Start Assistance inactive.

I have read various articles across the net and found speculation that it could be a ABS sensor, speed sensor, ABS unit fault, Reluctor ring failure etc.

I'll be taking the car into my indy that usually works on my car and will post on what the diagnosis and remedy is.

Cheers

Stealth,
 
#18 ·
Hey Guys,

Quick update as to what the garage told me this morning, basically I should disconnect the battery myself and leave it for 30mins.

See if the fault returns and then come back to them because some of the sensors may not be talking to each other.

Thanks that's fine if I were asking how to fix it myself but I wasn't. I've now booked it elsewhere and will be dropping it off tomorrow.

Stealth
 
#19 ·
Update

The car was inspected by an independent local to me and my place of work and several hours later it was confirmed that one of the speed sensors was the cause of all the faults!
Amazing to think how one sensor could take out 4 separate systems! Albeit they're all related to braking!
They replaced it (off side rear) and on collection relieved me of £110 for doing so! I'm not complaining...
Not bad in my opinion considering BMW wanted £99 just to take a look and couldn't get me in till Monday 19th!
Glad to have my car back and back to full power and able to stop properly!

Stealth
 
#20 ·
Stealth328Ci said:
Update

The car was inspected by an independent local to me and my place of work and several hours later it was confirmed that one of the speed sensors was the cause of all the faults!
Amazing to think how one sensor could take out 4 separate systems! Albeit they're all related to braking!
They replaced it (off side rear) and on collection relieved me of £110 for doing so! I'm not complaining...
Not bad in my opinion considering BMW wanted £99 just to take a look and couldn't get me in till Monday 19th!
Glad to have my car back and back to full power and able to stop properly!

Stealth
Result mate.

Sent from my iPhone using Tapatalk
 
#24 ·
I just had this issue with my 2005 116i. First symptom was complete loss of power 4 weeks ago while driving on Motorway at 70mph and flashing DTC warning on dash. After pulling over and restarting car issue did not reappear until last week when the random braking started to occur at all speeds.

Both ABS reluctor rings and corresponding sensors were replaced by indy BMW (Clayton Cars) for £550 including VAT.

If it has not already happened to you or if you are considering buying an older e87 definitely factor this into your maintenance budget.
 
#25 ·
Hi all,

I've just noticed this thread. I posted about my issues in a separate subject yesterday, I'm just wondering if anyone related to this thread has any advice. My traction control issues started around 4 months ago, all the same symptoms as have been explained here. Two new Reluctor rings cured it for around 5 weeks then I had the DTC light flashing again. The flashing and resulting braking had been occurring more frequently, approx every 30/40miles (every 3/4 journeys to work for me). I had both sensors replaced yesterday for genuine BMW sensors (garage showed me the invoice from BMW this morning). Since they have been changed, on both journeys especially on the motorway, the car is even worse. DTC light flashing 10x more often. What has gone wrong, is there a specific distance that the rings need to be from the sensors? The basic diagnostics test doesn't read any errors. How can I tell where my problem is coming from. The car is booked back in on Monday where they will fully inspect the sensors and rings etc. Are there any pointers I can give them? I've spent £400 altogether trying to resolve this issue and by putting two new sensors on I've only made it worse.

Any help would be greatly appreciated.
 
#26 ·
I would want to see the live data (via laptop or decent code reader) coming from all four ABS sensors. Obviously all four should be giving the same wheel speed, so I'd expect to see (at least) one anomaly.

An output check with a stationary car is useless.
 
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