BMW traction light

[Dettmer]

Hi. I have a traction light coming on intermittently and the car looses power. I can overcome this by switching off the traction control. I hear that it could be the sensor. How do I find out which one it is and is it easy to change?

Edited by Julietdelta on Saturday 17th February 11:01

[E-bmw]

1. Make sure you have 4 matching tyres of the best that you can afford.

2. Check tyres are inflated to the correct pressures.

3. Get back to us when you have checked/completed these as required.

BTW, it is the Traction Control or ASC or DSC light depending on the car IIRC.

Just because the light is coming on doesn't mean there is a problem.

More details on the car/circumstances of the warning would help as there are hundreds of VERY different BMWs with many different characteristics.

[B'stard Child]

What BMW model?

[Julietdelta]

E-bmw said:

1. Make sure you have 4 matching tyres of the best that you can afford.

2. Check tyres are inflated to the correct pressures.

3. Get back to us when you have checked/completed these as required.

BTW, it is the Traction Control or ASC or DSC light depending on the car IIRC.

Just because the light is coming on doesn't mean there is a problem.

More details on the car/circumstances of the warning would help as there are hundreds of VERY different BMWs with many different characteristics.

Hi. The tyres are all okay and might not be the best but certainly not the worst and all inflated to the correct pressure. The pressure light did come on recently though and only one tyre was 1 bar below what it should have been.
It’s a BMW 318 D SE BUSINESS EDITION .
It comes on when driving in the motorway. I’ve not seen that there is a trigger or pattern though. Came on once on my long journey up north and multiple times on the way back. Today I’ve been driving locally and no issues. She it comes on the engine looses power. The light is a triangle with a circle arrow.

[Julietdelta]

B'stard Child said:

What BMW model?

BMW 318 D SE BUSINESS EDITION Estate

[B'stard Child]

Julietdelta said:

B'stard Child said:

What BMW model?

BMW 318 D SE BUSINESS EDITION Estate

Could well be the reluctor rings expanding (due to rust) on the rear driveshafts rubbing on the ABS sensor and chewing through them.

If it's intermittent that's exactly the same symptoms I got initially - random traction control light and what felt like a misfire (the engine cutting power to get back the traction it though it didn't have)

Then it progressed (adding to the traction control warnings) to random tyre pressure warnings despite all the tyres being inflated to the correct pressure.

Finally it added total ABS failure to the mix and the dash lit up like a Christmas tree.

All of the warnings and driveability issues went away with the traction control turned off (although the dash still stayed lit up like a Christmas tree until the car was turned off) It didn't show any warnings on restart but after a few miles would be back again

Easy to check - jack the rear up one side at a time - remove the wheel and then extract the ABS sensor from the housing - look at the sensor if it's got wear to the end and the reluctor ring (looking down the hole that the ABS sensor sits in) has shinny bits on it then it's a good indication that the reluctor rings have expanded due to rust on the driveshafts underneath them.

[Julietdelta]

B'stard Child said:

Julietdelta said:

B'stard Child said:

What BMW model?

BMW 318 D SE BUSINESS EDITION Estate

Could well be the reluctor rings expanding (due to rust) on the rear driveshafts rubbing on the ABS sensor and chewing through them.

If it's intermittent that's exactly the same symptoms I got initially - random traction control light and what felt like a misfire (the engine cutting power to get back the traction it though it didn't have)

Then it progressed (adding to the traction control warnings) to random tyre pressure warnings despite all the tyres being inflated to the correct pressure.

Finally it added total ABS failure to the mix and the dash lit up like a Christmas tree.

All of the warnings and driveability issues went away with the traction control turned off (although the dash still stayed lit up like a Christmas tree until the car was turned off) It didn't show any warnings on restart but after a few miles would be back again

Easy to check - jack the rear up one side at a time - remove the wheel and then extract the ABS sensor from the housing - look at the sensor if it's got wear to the end and the reluctor ring (looking down the hole that the ABS sensor sits in) has shinny bits on it then it's a good indication that the reluctor rings have expanded due to rust on the driveshafts underneath them.

Thanks so much. Where do I find them, and if they do look expanded then are they easy to replace?

[B'stard Child]

Julietdelta said:

B'stard Child said:

Julietdelta said:

B'stard Child said:

What BMW model?

BMW 318 D SE BUSINESS EDITION Estate

Could well be the reluctor rings expanding (due to rust) on the rear driveshafts rubbing on the ABS sensor and chewing through them.

If it's intermittent that's exactly the same symptoms I got initially - random traction control light and what felt like a misfire (the engine cutting power to get back the traction it though it didn't have)

Then it progressed (adding to the traction control warnings) to random tyre pressure warnings despite all the tyres being inflated to the correct pressure.

Finally it added total ABS failure to the mix and the dash lit up like a Christmas tree.

All of the warnings and driveability issues went away with the traction control turned off (although the dash still stayed lit up like a Christmas tree until the car was turned off) It didn't show any warnings on restart but after a few miles would be back again

Easy to check - jack the rear up one side at a time - remove the wheel and then extract the ABS sensor from the housing - look at the sensor if it's got wear to the end and the reluctor ring (looking down the hole that the ABS sensor sits in) has shinny bits on it then it's a good indication that the reluctor rings have expanded due to rust on the driveshafts underneath them.

Thanks so much. Where do I find them, and if they do look expanded then are they easy to replace?

How handy are you mechanically?

The ABS sensors are easy to replace

Reluctor rings not so easy - driveshafts need to be removed to get to them - BMW won't replace the reluctor rings only the complete driveshaft but it can be DIY if you have the tools and provided the shafts aren't too rusty.

[Julietdelta]

B'stard Child said:

Julietdelta said:

B'stard Child said:

What BMW model?

BMW 318 D SE BUSINESS EDITION Estate

Could well be the reluctor rings expanding (due to rust) on the rear driveshafts rubbing on the ABS sensor and chewing through them.

If it's intermittent that's exactly the same symptoms I got initially - random traction control light and what felt like a misfire (the engine cutting power to get back the traction it though it didn't have)

Then it progressed (adding to the traction control warnings) to random tyre pressure warnings despite all the tyres being inflated to the correct pressure.

Finally it added total ABS failure to the mix and the dash lit up like a Christmas tree.

All of the warnings and driveability issues went away with the traction control turned off (although the dash still stayed lit up like a Christmas tree until the car was turned off) It didn't show any warnings on restart but after a few miles would be back again

Easy to check - jack the rear up one side at a time - remove the wheel and then extract the ABS sensor from the housing - look at the sensor if it's got wear to the end and the reluctor ring (looking down the hole that the ABS sensor sits in) has shinny bits on it then it's a good indication that the reluctor rings have expanded due to rust on the driveshafts underneath them.

Thanks so much. Where do I find them, and if they do look expanded then are they easy to replace?

[stevemcs]

Driveshafts are fairy cheap so sometimes it’s worth just putting a new driveshaft in.

[Julietdelta]

Thank you!!

[B'stard Child]

stevemcs said:

Driveshafts are fairy cheap so sometimes it’s worth just putting a new driveshaft in.

They aren’t cheap from BMW (if they actually have them avaliable) and they normally have a hefty exchange surcharge which makes the initial expense a lot more - From memory it was £800 each last year for my 1 series (250 of that was exchange surcharge)

However they only had one side (not the side I needed) so I went aftermarket and lets just say they were cheap and it shows (new and old below)



The aftermarket ones were £225 for the pair - as a result of fitting them - I’ve been able to refurb the originals an fit new reluctor rings to them and when the weather is better I’ll re-fit the originals back to the car. (I needed to keep the car on the road and I couldn’t take the risk around trying to replace the reluctor rings only and finding the shafts to have been too rusty so the rings were loose)

I’ll ebay the aftermarket ones as used for 6 mths

[stevemcs]

B'stard Child said:

They aren’t cheap from BMW (if they actually have them avaliable) and they normally have a hefty exchange surcharge which makes the initial expense a lot more - From memory it was £800 each last year for my 1 series (250 of that was exchange surcharge)

However they only had one side (not the side I needed) so I went aftermarket and lets just say they were cheap and it shows (new and old below)



The aftermarket ones were £225 for the pair - as a result of fitting them - I’ve been able to refurb the originals an fit new reluctor rings to them and when the weather is better I’ll re-fit the originals back to the car. (I needed to keep the car on the road and I couldn’t take the risk around trying to replace the reluctor rings only and finding the shafts to have been too rusty so the rings were loose)

I’ll ebay the aftermarket ones as used for 6 mths

Euros do list the reluctor rings, yes the pattern parts are not the same as genuine but for the average person and given the age of the car tend to work out the cheapest option.

[B'stard Child]

stevemcs said:

Euros do list the reluctor rings, yes the pattern parts are not the same as genuine but for the average person and given the age of the car tend to work out the cheapest option.

Agreed - I just wasn’t happy with the weedy look of the aftermarket ones compared to the originals - aftermarket clearly shares the same parts from 116i to 130i and with 265 bhp to play with on my car I’m going back to the originals (if it ever stops raining)

OP the reluctor rings are on the drive shafts at the bottom of the picture I posted - they are a band with square holes punched into it that is then press fitted over the driveshaft

It is on the reluctor rings that you need to see if there are shinney areas as that will indicate contact with the sensors