[medlyleeds]

Hi All

The car has constantly been pulling to the left since I got it
3 Series BMW. 15 plate 330d. 30000 miles. As far as I know not had any significant accidents and not gone through any major potholes etc
M-sport suspension. 19inch wheels. New Michelin pilot sport 4 non run flats (although same issue with previous runflats)
Recently had new super-pro bushes fitted to front - problem was ongoing prior to this - this was an attempted remedy
Constant pull to the left. If I let go of wheel car drifts off to left. Constant force required on wheel to make car go straight, however car does does go straight when wheel is centered. If car is on road that is crowned to the right - no force on wheel needed and either goes straight or sometime still pulls left.
Only position where wheel does not need any force applying is slightly off to the left
Wheel does not appear to self centre as well when turned to the left. When turned to the right it snaps back to centre, when turned left it returns to just of left of centre
When car is moving it feels very slightly easier to steer left than right. Does not seem to the be the case when stationary
The problem has been constant despite a number of wheel alignments. After an alignment it appears to be almost (but never completely) eradicated but over the next few hundred miles it returns slowly.
It has had numerous wheel alignments and the front tyres have been rotated around but this has made no difference

I have attached the latest readout

View post on imgur.com

Any help would be much appreciated

[HighlandPete]

Originally Posted by medlyleeds

Hi All

The car has constantly been pulling to the left since I got it
3 Series BMW. 15 plate 330d. 30000 miles. As far as I know not had any significant accidents and not gone through any major potholes etc
M-sport suspension. 19inch wheels. New Michelin pilot sport 4 non run flats (although same issue with previous runflats)
Recently had new super-pro bushes fitted to front - problem was ongoing prior to this - this was an attempted remedy
Constant pull to the left. If I let go of wheel car drifts off to left. Constant force required on wheel to make car go straight, however car does does go straight when wheel is centered. If car is on road that is crowned to the right - no force on wheel needed and either goes straight or sometime still pulls left.
Only position where wheel does not need any force applying is slightly off to the left
Wheel does not appear to self centre as well when turned to the left. When turned to the right it snaps back to centre, when turned left it returns to just of left of centre
When car is moving it feels very slightly easier to steer left than right. Does not seem to the be the case when stationary
The problem has been constant despite a number of wheel alignments. After an alignment it appears to be almost (but never completely) eradicated but over the next few hundred miles it returns slowly.
It has had numerous wheel alignments and the front tyres have been rotated around but this has made no difference

I have attached the latest readout

Any help would be much appreciated

The rear toe is in tolerance, but the way it is set is not helping the drift left issue, it also means the trust angle is not at zero. I'd be starting with those calibrations.

What I see does fit with what you are experiencing,

These cars can be pretty sensitive. What other readouts have you had before, as 'corrected' geometry?

[medlyleeds]

Hi

thanks for the reply

the one before it is below

it has been fine a whole load of times and mostly been perfect but it still has not fixed the problem.

it feels like something is pulling the steering left but the alignment does not explain it. Brakes seem ok and the tires have been rotated.

[HighlandPete]

Originally Posted by medlyleeds

Hi

thanks for the reply

the one before it is below

it has been fine a whole load of times and mostly been perfect but it still has not fixed the problem.

it feels like something is pulling the steering left but the alignment does not explain it. Brakes seem ok and the tires have been rotated.

Was the issue better when new tyres were fitted? Then get worse again?

What interests me is the way it steers, differences in left and right behaviour and self-centre feel. That looks to be involving the steering rack calibration (SAS). There are ways to test if that is involved yourself, if you are so minded and handy with the spanners.

[medlyleeds]

I think the new tyres generally made things worse but I don't think it actually made the pulling any different. Everything became really loose/sloppy and it seemed to make the steering wheel even more off centre. I think the sloppy feel came from going from run flats to go flats. Once the super-pro bushes went on the steering was really tight again (actually felt like me E90 did) but the pull was still there and so was the difference in steering left and right. What I do notice is that after each alignment things become better for a short but then slowly go back to pulling left.

Interestingly you're the 3rd person that has mentioned steering rack calibration being the cause. No one that has done an alignment so far has reset it/re-calibrated it.

I did read this though in a BMW service document and I wonder whether things have come out of sync somehow. What I can't seem to find anywhere is whether the steering axis "sensor"/system has any effect on the power assistance that the EPS rack provides or whether it is just something that feeds into the stability control/ABS etc



I am willing to try anything because the problem is driving me mad.
What is the best way to check?

[G50]

I had a similar problem on a merc, but it pulled towards either camber, changing the control arms fixed it. If yours is only pulling left, it sounds more like something is bent somewhere.

You mention it gets better after an alignment for a short period, do you have a copy of the settings pre-alignment?

[medlyleeds]

Originally Posted by G50

I had a similar problem on a merc, but it pulled towards either camber, changing the control arms fixed it. If yours is only pulling left, it sounds more like something is bent somewhere.

You mention it gets better after an alignment for a short period, do you have a copy of the settings pre-alignment?

Yeah I've not got all of them but the ones I've got are attached below. The ones dated 2/8/19 are a few months after the bushes were fitted so the guy felt that it was just the bushes settling in. Every time he does it he lets me pick the centre point of the wheel so I'm happy with it and as far as I can tell he does exactly to spec. Ride height is measured and the car is weighed down. Only thing they've not done is reset steering angle sensor.

[HighlandPete]

Originally Posted by medlyleeds

Interestingly you're the 3rd person that has mentioned steering rack calibration being the cause. No one that has done an alignment so far has reset it/re-calibrated it.

I did read this though in a BMW service document and I wonder whether things have come out of sync somehow. What I can't seem to find anywhere is whether the steering axis "sensor"/system has any effect on the power assistance that the EPS rack provides or whether it is just something that feeds into the stability control/ABS etc?

Before trying any physical adjustment, a couple of observations.

You've mentioned it can still pull left when running on the crown of the road, so almost certainly eliminates camber pull from a sloppy alignment and/or loose components. Differences in feel 'left to right' can indicate driving straight is applying steering torque (therefore power) to the rack. This can either be due to the SAS not calibrated to zero, or the setup is not neutral when driving straight. If so, when you come off centre, (in your case to the left, it may be on zero, (no steering torque). Feel from that point should be more equal, than when on centre, where left is more relaxed, right requires more steering effort/torque.

When driving straight (to keep straight), what position is the steering wheel? Off centre?

You are driving the ideal curve to stop the steering pull... does it then feel pretty much equal, if you need to steer left or right a little bit?

[kern417]

connect your car to a BMW scan tool and see if the steering angle is reading 0 when the wheel is straight. sometimes you can align the wheels with the steering wheel straight, but the sensor will read a few degrees in either direction and the car will try to correct itself.

basically, it could be a steering rack/angle sensor issue.

[medlyleeds]

Originally Posted by HighlandPete

Before trying any physical adjustment, a couple of observations.

You've mentioned it can still pull left when running on the crown of the road, so almost certainly eliminates camber pull from a sloppy alignment and/or loose components. Differences in feel 'left to right' can indicate driving straight is applying steering torque (therefore power) to the rack. This can either be due to the SAS not calibrated to zero, or the setup is not neutral when driving straight. If so, when you come off centre, (in your case to the left, it may be on zero, (no steering torque). Feel from that point should be more equal, than when on centre, where left is more relaxed, right requires more steering effort/torque.

When driving straight (to keep straight), what position is the steering wheel? Off centre?

You are driving the ideal curve to stop the steering pull... does it then feel pretty much equal, if you need to steer left or right a little bit?

Yeah basically it does the following

Road crowned left pulls left
Road flat pulls left
Road crowned right - either goes straight or very mild pull to the left, but no feeling of left pull on the steering wheel. Only time where I feel that the wheel isn't fighting with me is on roads that are crowned quite a lot to the right.

When driving straight the steering wheel is perfectly centered (where I asked the wheel alignment guy to centre it) but to keep it in this position I have to apply force to it, when I let go it moves ever so slightly to the left and then the car goes off to the left. For it to need no force applying it needs to be just off to the left, which makes the car go left - like you mentioned this is the ideal curve that the car wants to take.

With regards to the steering feel. It is difficult to tell exactly but I feel like all turns to the left are easier than all turns to the right (probably more noticeable at low speed and less so at motorway speed - I guess because of the amount of turning on local roads vs. small adjustments on the motorway). The difference between left and right is probably very small but definitely noticeable. Even right hand turns on a road that is crowned to the right feel difficult where you would expect them to be easy, however when the road is crowned to the left the steering is easier to turn.

[medlyleeds]

Originally Posted by kern417

connect your car to a BMW scan tool and see if the steering angle is reading 0 when the wheel is straight. sometimes you can align the wheels with the steering wheel straight, but the sensor will read a few degrees in either direction and the car will try to correct itself.

basically, it could be a steering rack/angle sensor issue.

Hi. Thanks for the reply. Yeah you're not the only who has suggested this but I can't find anything definitive on whether the steering angle sensor has any bearing on the power steering assistance level or self centring or whether it just provides information for the driving stability control etc. It is the only thing that has not been done so certainly willing to try it.

Would something like this work for diagnostic/reset purposes?

https://www.ebay.co.uk/itm/Ethernet-...53.m1438.l2649

[kern417]

Originally Posted by medlyleeds

Hi. Thanks for the reply. Yeah you're not the only who has suggested this but I can't find anything definitive on whether the steering angle sensor has any bearing on the power steering assistance level or self centring or whether it just provides information for the driving stability control etc. It is the only thing that has not been done so certainly willing to try it.

Would something like this work for diagnostic/reset purposes?

https://www.ebay.co.uk/itm/Ethernet-...53.m1438.l2649

When you're turning and let go of the wheel, it's the same assist that pushes it back straight. If you're driving for an extended period at say 5*, it'll try to adjust straight as a part of the programming. I've experienced this on other cars as well when I replaced my steering wheel and didn't attach it perfectly straight. I got the car aligned so the front wheels matched the steering wheel, but the angle sensor was off so it kept trying to adjust me to the right.

ISTA should be what you need. That's what BMW uses. The other option is to get an alignment at the dealer where they hook up the sensor as a part of the alignment process. If they can't get a good reading or it's off, then you know it's bad. I haven't messed with the steering wheel in my f-series, but my understanding is they cannot be off-axis. So the only way the angle sensor and the steering wheel can be off is a sensor/rack issue.

[HighlandPete]

To be honest, I'm not sure what is going on.

We typically have three areas that cause pull, besides damage. Alignment, tyres, suspension wear. Or a combination of two, or all three. You have swapped tyres. Have you tried side to side? Several alignments, with decent readings. Changed some buses, Is everything else tight?

Not totally convinced it is definitely the SAS, as you say your wheel in on centre when driving straight, but agree it needs checking. SAS does need to be absolute zero 'on centre' to prevent oddities in the steering. How it would have lost its calibration is where I have issue.

Your comment... Just trying to eliminate a possible 'physical' error. These EPS systems are very sensitive.

Originally Posted by medlyleeds

When driving straight the steering wheel is perfectly centered (where I asked the wheel alignment guy to centre it) but to keep it in this position....

Is that aligned to the dash, like paddle or stalk positions, or do you mean you have it different to where the alignment guy wanted it centred?

[medlyleeds]

Originally Posted by HighlandPete

To be honest, I'm not sure what is going on.

We typically have three areas that cause pull, besides damage. Alignment, tyres, suspension wear. Or a combination of two, or all three. You have swapped tyres. Have you tried side to side? Several alignments, with decent readings. Changed some buses, Is everything else tight?

Not totally convinced it is definitely the SAS, as you say your wheel in on centre when driving straight, but agree it needs checking. SAS does need to be absolute zero 'on centre' to prevent oddities in the steering. How it would have lost its calibration is where I have issue.

Your comment... Just trying to eliminate a possible 'physical' error. These EPS systems are very sensitive.


Is that aligned to the dash, like paddle or stalk positions, or do you mean you have it different to where the alignment guy wanted it centred?

Yeah tyres have been swapped side to side both back and front set. The problem was going on with the previous and new tyres so I figure tyres aren't the issue. Alignment wise...I have had it done so many times I have lost count. Each alignment does seem to improve the situation temporarily and each subsequent check after alignment does seem to show that things have moved slightly, however at the time of alignment everything seems to be tight and no one can ever find any suspension damage or anything loose. The track rod ends are always really tight. I can't see them being an issue or moving in between adjustments. The steering has been adjusted to be dead centre..stalks level etc

Regarding the SAS. So I picked up a cheap diagnostic computer (Autophix 7910). The steering axis sensor function does not work on the F30 as I do not think there is actually an individual sensor that can be reset (as previously mentioned). The steering position comes from the EPS unit and seems to be "learnt" via a process of interaction between the EPS and chassis management system which uses the EPS motor position as a starting point. My computer picked up an error code on the EPS and is able to live stream some data on pinion angle.

In the centre the pinion angle is 0
When you steer all the way to the left the pinion angle goes up to 490 (1 and a bit turns)
So far so good right
But when you steer to the right, as soon as you pass the centre mark the angle sensor starts to read stupid numbers like 2500000 (see pictures below)

I am not sure if that's just a quirk of the diagnostic computer or whether there is an issue in the EPS unit. I am also getting an error that says EPS voltage low and steering assistance maybe reduced.

See pictures below

First is with wheel turned all the way to the right and second is with it turned all the way to the left (ignore the velocity, I think i might have been moving it slightly when I took the picture)

[medlyleeds]

Anybody have any idea why the pinion angle would have a value that doesn't make sense like that?

[t5pilot]

Originally Posted by medlyleeds

Anybody have any idea why the pinion angle would have a value that doesn't make sense like that?

I know nothing about this. But having read through, I suspect that EPS module is defective, confirmed by the readings above.

[gggsss]

Originally Posted by medlyleeds

Yeah tyres have been swapped side to side both back and front set. The problem was going on with the previous and new tyres so I figure tyres aren't the issue. Alignment wise...I have had it done so many times I have lost count. Each alignment does seem to improve the situation temporarily and each subsequent check after alignment does seem to show that things have moved slightly, however at the time of alignment everything seems to be tight and no one can ever find any suspension damage or anything loose. The track rod ends are always really tight. I can't see them being an issue or moving in between adjustments. The steering has been adjusted to be dead centre..stalks level etc

Regarding the SAS. So I picked up a cheap diagnostic computer (Autophix 7910). The steering axis sensor function does not work on the F30 as I do not think there is actually an individual sensor that can be reset (as previously mentioned). The steering position comes from the EPS unit and seems to be "learnt" via a process of interaction between the EPS and chassis management system which uses the EPS motor position as a starting point. My computer picked up an error code on the EPS and is able to live stream some data on pinion angle.

In the centre the pinion angle is 0
When you steer all the way to the left the pinion angle goes up to 490 (1 and a bit turns)
So far so good right
But when you steer to the right, as soon as you pass the centre mark the angle sensor starts to read stupid numbers like 2500000 (see pictures below)

I am not sure if that's just a quirk of the diagnostic computer or whether there is an issue in the EPS unit. I am also getting an error that says EPS voltage low and steering assistance maybe reduced.

See pictures below

First is with wheel turned all the way to the right and second is with it turned all the way to the left (ignore the velocity, I think i might have been moving it slightly when I took the picture)

Can you solve the problem? I have same problem with you. But my car pulling to thr right. symptomps are totaly same. Steering turning easy to the right at low speed, car only drive straight at left crowned roads.

I am visit bmw 3 times, they said your alignments are perfect. This car should not pull to the right. Thep offered replace steering assembly but there was no guarantee that the problem would be solved. And this is really expensive repair for only a trying attemp.

I lost my enet cable so I can not measure pinion angle. If you solve the problem with this sensor, I will try to find cable and test it. You're the only person I've ever seen with the same problem as me, so you are my only hope

[Fazil]

I had similar possible issues last year and this year.
340i, M Sport, 19 inch.
Had lots of Kwikfit hunter alignments, All good, printout confirmed.... Soon as I drove, it'd go out of whack. Took it to 3 different places with hunter machines, couldn't get it to maintain. Nothing to do with hitting potholes straight after or anything like that.


Took it to bmw, cost about 78 quid discounted down. Full KDS alignment. Did it twice, wasn't satisfied. Third time, one of the head techs came in on Saturday specially for me. Called me into workshop, to put steering wheel myself as I liked it. After that, was OK for a while. This was last year.

This year had some components replaced on suspension, so full KDS alignment done by BMW under warranty as required due to suspension part changes.
First time supposedly done, wouldn't maintain. 2nd time done again, toe was out, but has maintained for about 6 weeks now despite hitting multiple unavoidable potholes. I did ask to see if they'd change the bolts they adjust, I don't know if they did, but whatever they did the last time, it has maintained and after about 18 months of ownership, I was finally satisfied the car was tracking straight after an alignment, and staying that way.