[aaroncoppen19]

Hi so I recently bought a 2008 bmw 320i E90 and it had a problem where I would go up to 60/70/70mph the put my foot down and the traction control symbol would flash and cut power, if I turn the DTC off the car works as it should but I’ve recently had 2 rear abs sensors and rings replaced to try fix the problem but ive ran out of ideas on what it could be, any help would be appreciated!!

[PhaceN52]

What kind of tires do you have on?

[aaroncoppen19]

Originally Posted by PhaceN52

What kind of tires do you have on?

I’ve got tomket sport 225/40zr18

[PhaceN52]

The problem is present also with warmer temperatures or just now that's cold? Does the car squat a lot when you floor it? It could be tires, some suspension component on the rear like control arms... Dunno

[aaroncoppen19]

Originally Posted by PhaceN52

The problem is present also with warmer temperatures or just now that's cold? Does the car squat a lot when you floor it? It could be tires, some suspension component on the rear like control arms... Dunno

This is happening in all weather and temperatures, I also don’t think the car squats when I put the pedal down

[Greyfox]

So you are hard accelerating after hitting 60/70mph?

Correct tire size?

[aaroncoppen19]

Originally Posted by Greyfox

So you are hard accelerating after hitting 60/70mph?

Correct tire size?

Anything I do after 60/70 hard or soft acceleration it just flashes traction control cutting power but sometimes if I take foot off acceleration and put it back on it lets me accelerate further but still flashes. I have a vid but can’t post it on here. Also not even sure I’ll have to check about tire size, just bought the car at Xmas

[Greyfox]

Originally Posted by aaroncoppen19

Also not even sure I’ll have to check about tire size, just bought the car at Xmas

If there is a mismatch between tires front to rear or even between the whole set then that would cause issues with the rotations being reported to the DTS.

Also I'd check the tire pressures and make sure they are also in spec.

[aaroncoppen19]

Originally Posted by Greyfox

If there is a mismatch between tires front to rear or even between the whole set then that would cause issues with the rotations being reported to the DTS.

Also I'd check the tire pressures and make sure they are also in spec.

All 4 are matching yes, but I’ll check the pressures as I though a couple looked a bit flatter than normal the other day, cheers for the reply!

[crashoverride]

Sounds like it might be a suspension issue. If tires are not sitting right and say less than is in contact the road it will cause the tires to spin. Basically the traction control pops up if the wheels spin it then brakes that tire to stop it from spinning like an extreme example is in snow you need to turn off traction control to allow to spin to eventually find some traction and get you moving (opposite of what I would think) I would check the shocks and suspension to make sure your tires are getting full contact.

[aaroncoppen19]

Originally Posted by crashoverride

Sounds like it might be a suspension issue. If tires are not sitting right and say less than is in contact the road it will cause the tires to spin. Basically the traction control pops up if the wheels spin it then brakes that tire to stop it from spinning like an extreme example is in snow you need to turn off traction control to allow to spin to eventually find some traction and get you moving (opposite of what I would think) I would check the shocks and suspension to make sure your tires are getting full contact.

Okay thanks, cars back in the garage next Tuesday. I’ll bring this up to him to check, appretiate the reply👍

[e90yyc]

I’m not suggesting this is your issue, but I had a number of DSC gremlins that I couldn’t figure out (and believe me, I tried everything…). Turned out the module was bad. Replaced it with a used part and issues went away.

Just something to keep in mind before you blow your brains out trying to solve this, assuming it doesn’t end up being one of the more obvious issues that others have pointed out (wheels/tires, WSS, etc).

[aaroncoppen19]

Originally Posted by e90yyc

I’m not suggesting this is your issue, but I had a number of DSC gremlins that I couldn’t figure out (and believe me, I tried everything…). Turned out the module was bad. Replaced it with a used part and issues went away.

Just something to keep in mind before you blow your brains out trying to solve this, assuming it doesn’t end up being one of the more obvious issues that others have pointed out (wheels/tires, WSS, etc).

What do you mean by the module was bad? Sorry I’m still new to all this haha

[gbalthrop]

Originally Posted by aaroncoppen19

... 2008 bmw 320i E90... 60/70/70mph the put my foot down and the traction control symbol would flash and cut power, if I turn the DTC off the car works as it should but I’ve recently had 2 rear abs sensors and rings replaced to try fix the problem...

Hope YOU/ your $hop, a large parts retailer near you have a Scan Tool or Diagnostic Software (INPA/ISTA) that can read DSC Fault Codes, particularly Wheel Speed Sensor codes and also "Live Data" showing actual wheel speed signals received by DSC (Dynamic Stability Control) Module.

Without knowing WHAT DSC fault codes you have, and/or what the Live Data shows for Wheel Speed Signals received by DSC, we CANNOT offer any meaningful suggestions.

You SHOULD have a sticker on the B-pillar, visible when opening Driver Door, that indicates original factory tire size. ALL FOUR tires must be SAME "Rolling Circumference". That means NO significant difference in tire size, tread wear, or inflation. Wheel Speed signals, even with proper function of Sensors and their signals, can vary between wheels due to ANY difference in "Rolling Circumference".
George

[e90yyc]

Originally Posted by aaroncoppen19

What do you mean by the module was bad? Sorry I’m still new to all this haha

All good! We’re all here to learn.

Long story short (edit: nvm, it’s long), I manual-swapped my car (removed auto transmission and put in manual transmission) and immediately after I did this, I started experiencing issues with things that are controlled by the DSC (Dynamic Stability Control) module. This module is a combination of electronics and hydraulic pump that performs ABS function, stability/traction control, cruise control, and a number of other things.

In my case, when I’d go over bumps, the module would cut power. When I would turn cruise control on, throttle would surge on and off for ~5 seconds, and then cruise would deactivate.

Because this all started immediately after I did a ton of work on my car, I ended up sinking a stupid amount of time into troubleshooting. This was both because I thought it couldn’t be a coincidence, and because there actually were NOT any error codes—at least nothing beyond some very generic code that got me no closer to the problem.

In the end, I simply replaced the DSC module and everything worked perfect. As for what caused it to fail: Might have been coincidence, could have been something I did while doing all the wiring for swap; dunno.

Just keep in mind that if everything else checks out, it’s possible the module itself could be faulty even if there are no error codes. I wouldn’t jump straight to replacement though, especially if you’re paying someone to do the work.