E46 ABS & ACS FAILURE

[bmw328]

Hello all,
Hope Someone could please explain or shed some light on this unexpected matter. On the 2Nd of April 2013 I was traveling to work in my 2001 E46 320I, an animal ran in front of me & to try and avoid the accident I slammed on the brakes and swerved to the left.
After waking up in hospital with a skull fracture, broken right tibia & fibula, dislocated hip, 2 broken fingers & a concussion a short term memory loss from hell. I started to puzzle WTF could have gone wrong. (Car did NOT have any ABS or ASC light illuminated on the dash & all systems worked as they should when last diagnostic was performed less than 2 weeks before accident)
According to the pictures I took at the accident scene it would appear that the front wheels locked up and car swerved to the right instead of to the left as where I swerved.
And the reason I say only the front wheels locked up is because the rear wheels drive the speedo gear on the differential (On impact the instrumental cluster got smashed and therefore got stuck on a speed) and because the skid marks on the road is just 2 instead of 4?)
Any comments would be helpful & appreciated.

 

[moranor@axis]

1st... hope you alright and no permanent damage was done

e46 does not have a speed sensor in the diff each wheel has one... when i spin up the rear wheels the speedo does not go up with the Rpm so i assume it takes the speedo reading from the front...

is it possible the skid marks are from when the tires were sideways to the direction the car was traveling? once in that situation there is little the electronics can to to correct things...

 

[Solo Man]

I am sorry to hear about your accident. Also sorry that i cannot help with an explanation as to what went wrong. My question however is: were you wearing your seatbelt at the time of the accident?

 

[bmw328]

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[OppositeLockMT]

Uh oh, I think I should get my DSC and ABS sorted, I have a wheel speed sensor fault.

Sorry to hear about the accident.

 

[S1NGH 001]

Sorry buddy

 

[bmw328]

1st... hope you alright and no permanent damage was done

e46 does not have a speed sensor in the diff each wheel has one... when i spin up the rear wheels the speedo does not go up with the Rpm so i assume it takes the speedo reading from the front...

is it possible the skid marks are from when the tires were sideways to the direction the car was traveling? once in that situation there is little the electronics can to to correct things...

Hello Moranor,

I know the ABS & ASC system got a speed sensor on each wheel hub, I was assuming the E46 was the same as the E30, E32, E34, E36 regarding the Speedometer input on the Instrumental Cluster (They all get there input for the speedo from the Diff sensor)

 

[moranor@axis]

no sensor on e46 diff

what speed were you traveling before you started braking?

 

[bmw328]

I am sorry to hear about your accident. Also sorry that i cannot help with an explanation as to what went wrong. My question however is: were you wearing your seatbelt at the time of the accident?

Hello Solo Man,

Yes, I NEVER drive without my safetybelt.
If I didn't I'm sure I wouldn't have been typing this message. (All side impact airbags deployed - Doors & Head tube airbags

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no sensor on e46 diff

what speed were you traveling before you started braking?

I really don't know. But the car was fitted a newly build engine & haven't even done 1000KM before the accident. I was busy driving the new engine in, so the speed I can guarantee should have been under 120 KMH.

 

[Peejay]

Maybe the sensors failed. :fencelook:

 

[moranor@axis]

being a high speed incident some skid marks are too be expected even with the electronics 100%

I think you can chalk it up to being unlucky... the ripples from the patch work on the tar would also have made it difficult to regulate traction...

 

[Prev]

Damn those pics look hectic. Glad you survived. :thumbs:

Lesson to those that dont' use safety / seat belts.

 

[Solo Man]

I am sorry to hear about your accident. Also sorry that i cannot help with an explanation as to what went wrong. My question however is: were you wearing your seatbelt at the time of the accident?

Hello Solo Man,

Yes, I NEVER drive without my safetybelt.
If I didn't I'm sure I wouldn't have been typing this message. (All side impact airbags deployed - Doors & Head tube airbags

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no sensor on e46 diff

what speed were you traveling before you started braking?

I really don't know. But the car was fitted a newly build engine & haven't even done 1000KM before the accident. I was busy driving the new engine in, so the speed I can guarantee should have been under 120 KMH.

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I am sorry if it sounded as if i was trying to imply anything. After seeing the pictures it seems as if no airbag or seatbelt could prevent serious injury! Hope you will recover soon!

 

[moranor@axis]

out of interest what did you hit?

 

[applehero]

Well first off, I think you are lucky to be alive right now. Has anyone seen what the steering wheel looks like?? (Let alone the fact that it is detached).

Second, from all of what you are saying I think it's more likely that the details around what happened just before your accident will never be know entirely. If the skid marks are indeed yours, it's highly likely you swerved right.

Third, it doesn't look like the ABS kicked in - The skid marks look consistant - no typical ABS skid marks. However that could be also what it looks like in the picture.

I would agree that it is more likely that the front wheels locked up, than the rears. Purely from circumstantial cases, I am aware that the speedo does "freeze" at the speed of impact.

Glad you are okay, and happy driving!

 

[Kish2604]

Whoa... You are lucky to be alive... Where did your head fit in all that?...

What I can tell you is that each wheel has a speed sensor just below the caliper that records wheel rotational speeds and in combination with the steering angle sensor and the pitch/yaw sensor then intervenes when the car measures a loss of traction... Also the feed for the speedo comes from signal from the left rear wheel sensor..

Instead of a asc/dsc failure which will cause a warning light to illuminate on the dash I think a contributing factor is actually worn/defective dampers.. That will cause your long lock up marks..

 

[bmw328]

out of interest what did you hit?

The other think that's weird is after car left the road the car actually skid sideways (
Turned the direction I intended), it skid sideways with the driverside straight into 2 trees that is about a m apart (the driver door got smashed 1st, because the A pillar and firewall collapsed the car rolled over on its side and smashed the roof and dash too after all that the trees acted as a spring and returned the car back on its wheels but like 1 or 2 m from the trees)

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Whoa... You are lucky to be alive... Where did your head fit in all that?...

What I can tell you is that each wheel has a speed sensor just below the caliper that records wheel rotational speeds and in combination with the steering angle sensor and the pitch/yaw sensor then intervenes when the car measures a loss of traction... Also the feed for the speedo comes from signal from the left rear wheel sensor..

Instead of a asc/dsc failure which will cause a warning light to illuminate on the dash I think a contributing factor is actually worn/defective dampers.. That will cause your long lock up marks..

In the accident I actually hit my head against the A pillar (the a pillar was moved to where the steering columb used to be therefore the the tube airbag deployed between driver and passenger seat), I actually bought up the wreck and it's sitting at home, how does the dampers actually look like because I really need to know what failed.

 

[Peejay]

Well seems as if the dampers or maybe even the springs failed to push down hard enough on the road to enable your rear tyres to grip the road.

However that been said it could still be that they couldn't take the load from the swerving. Remember they are designed for normal driving and not for racing. They have very moderate of slightly higher then moderate handling capacity

 

[bmw328]

Well seems as if the dampers or maybe even the springs failed to push down hard enough on the road to enable your rear tyres to grip the road.

However that been said it could still be that they couldn't take the load from the swerving. Remember they are designed for normal driving and not for racing. They have very moderate of slightly higher then moderate handling capacity

Where is the dampers located? I did have a previous incident with the same car where the back spun out while going around a offramp at under 50kmh. (nothing was hit or damaged - I am used too e36s and never had this issue. I understand that if I was racing or something and the accident happened "yes" but as I previously stated I didn't drive at high speed. 120kmh being the max I drive that car at highway speeds. I estimate that the accident accrued between 80 and 100kmh. Maybe u are right about the "dampers" and springs. But how can I check it because I wont rest until I know what tried to kill me. I do know that the car had new front control arm bushes and new control arm in front (control arms was replaced day before accident because of 2 worn ballpoints)

 

[Kish2604]

Dampers are shocks...