z4 steering seized - EPS?

E

ex4x4

Member
 county Durham
Hi Folks -
My name is Alistair - a 44 year old maintenance tech for car manufacturing company. Ive owned and self maintained numerous cars over the years - more of a passion than a money saving exercise.
Im new to this forum, and unfortunately my first post is a request for some advice.
Ive trawled through lots of posts and web sites, but as of yet unable to find anyone with the same concern as my Z

I bought a 2003 2.2 Z4 late last year as a summer fun toy and part restoration project ( needed a bit TLC but nothing major)
I had drove for a few weeks without concern. Then I parked her up over the winter months, occasionally starting her and letting her get up to temperature - to keep the damp out.
Last time I started her the EPS light came on and stayed on. The steering is extremely heavy to the point that it felt like I would snap something if I tried any harder to turn the wheel.
Using certain posts and web advice, I ve tried without success to investigate concern.
fuse 22 - ok
fuse 64 - ??? unable to find.
Main power to motor - 13.6 v whilst engine running
main ground - good
Tried using a C110 diagnostic tool - tested eps - no faults found.
disconnected battery - still same.

Ive heard of a lot of concerns with intermittent ( sticky steering) in higher temps but this is constant solid steering in January temps in the UK.

what would be your advice - without breaking the bank for a new steering assembly???

Many thanks for any input
Alistair
 
First off welcome to the forum
Interesting topic as i recently purchased (knowingly) a Z with sticky steering or in worse case faultmode / light on dash & no steering assistance
I'm sure mine is battery drain / low power related but before i reached that conclusion my indy tweaked the steering column which removed any stickiness that was present before
Partway down the column where the motor & column connect there is a shim that adjusted one way makes steering mega stiff hence the other way makes it light .
Undo the torx or hex heads , mark where the shim is & literally 1mm either way has effect on smoothness .
Its another possible to try before swapping out the whole thing :thumbsup:
Oh & don't forget the pics of your car :poke: :D
 
Thanks for the reply - i'll certainly give it a go.
It just seems strange how the concern appeared. the car was fine then not - without been driven inbetween.
Once the rain stops - Ill get out and have a look at the shim. Ill post back any findings.
As for pics - I ll get some up on here when she looks a bit more presentable - she's parked in my garden at the moment - hibernating!!
 
ex4x4 said:
Thanks for the reply - i'll certainly give it a go.
It just seems strange how the concern appeared. the car was fine then not - without been driven inbetween.
Once the rain stops - Ill get out and have a look at the shim. Ill post back any findings.
As for pics - I ll get some up on here when she looks a bit more presentable - she's parked in my garden at the moment - hibernating!!
Click to expand...

Once you've found the part to adjust have the car running so as you can turn the wheel whilst adjusting the shim , should add i haven't done this myself , my indy did the work after i came across a mention of it trawling back through the forum :thumbsup:
 
Ive found one pic from when i bought her.
Quite a tidy car for 13 years old - just the odd battle scar here and there.
z4.JPG
 
First check if it's a 'hardware failure' or a 'software failure':
Put the front on axle stands and see if the steering wheel turns lightly.
If it doesnt, there's some physical obstruction in the rack/column/knuckles etc. (rust/seize/broken gear whatever)
If it does, there's something wrong with the eps.
 
well - just been out and raised car off front wheels.
steering is free as a bird with engine running -turning lock to lock numerous times without binding - it would appear EPS is functioning correctly??
When car lowered onto wheels - steering returns to being very stiff. - tyre pressures ok.
Have lubed the steering knuckle joints - still no joy.
May have to get it back up on ramps and remove under trays for closer inspection.
were getting somewhere at last :)
 
ex4x4 said:
well - just been out and raised car off front wheels.
steering is free as a bird with engine running -turning lock to lock numerous times without binding - it would appear EPS is functioning correctly??
When car lowered onto wheels - steering returns to being very stiff. - tyre pressures ok.
Have lubed the steering knuckle joints - still no joy.
May have to get it back up on ramps and remove under trays for closer inspection.
were getting somewhere at last :)
Click to expand...

I think you have slightly misunderstood GuidoK regarding the EPS.
the fact that it turns when not loaded implies there is a issue with the EPS.
The fact that the EPS light is on means the car knows there is an issue and therefore there will be a code somewhere. Perhaps a scan on a better/different scanner is the next step as there is definitely something amiss and the car knows it. That or Mr Wilks' shim mod might be worth a go.
 
Actually I ment to steer the car with the front wheels off the ground but also with the engine off (so no power steering). To see if the mechanics work.
No strange notches, seizing or anything that could trip some kind of safety/issue in the EPS.
with the wheels off the ground there is/should be no resistance, so if there is, it's a hardware failure in the rack or so.
But apparently there isn't.

But indeed if you have a light, there is always a code.
If you cant find that code, the codereader is not compatible for that system (or the code reader is faulty)
 
Ok so today I raised front end off ground and without ignition, turned steering wheel lock to lock several times - nothing. No grinding , graunching, squeeking etc etc.
So im now on the look out for a decent code reader ( unlike the C110 - which I suspect is counterfeit)
will keep this thread updated with my findings and photos where applicable.
wish me luck!!
 
Hi and welcome.
I'm not as experience as some people on here when it comes to Z4 but I had a similar fault on my Honda S2000 with its EPS when it had a half flat battery, gave the battery boost charge and this reset the fault..
Just wondering if this could be the same as your car has not been used over winter.
 
I think most people that are into real troubleshooting and coding get an INPA usb interface. (that's a (modified)KKL or Dcan interface which is advertized to work with INPA)
The software has a very steep learing curve (INPA/DIS/NCSexpert/ISTAD (rheingold)) and not all sellers have a good software install package but it's the software that can do the most, as it's the software the dealer use or even the factories use.
INPA: general diagnostic program for most bmw's up to the e85. Does advanced diagnostics and some coding (special coding tasks)
Runs under windows and needs EDIABAS as a sub program (ediabas=database interface for bmw; runs in background)
DIS: general diagnostic program. Runs under unix, so is used as an image with VMware
NCS expert: coding, for instance functionality for lights windows, roof etc
ISTAD: new version that replaces DIS and INPA. also sometimes donwloadable as 'Rheingold' (ISTA-D(iagnostic) and ISTA-P(rogramming) are the latest BMW tools that the dealer uses I think. They are usually used with an ICOM interface (very fast obd2 and fibre optic interface), but in the 'warez' community some whizkids made istaD compatible with the cheap kkl/D-can usb interface. All with the ediabas software running in the windows background)

Remember, all these programs are 'illegal' (warez), they are hacked and made to interface with a kkl usb/obd2 cable. So there is no real helpdesk or backup and the install can be really dodgy. There are sellers of these software that have programmed an installation program around it so it is a 'one click installation'. If that works ok or not depends on the seller.

They are definately not as easy to use as a C110 or something like an autel maxidas, but have more advanced possibilities. The most difficult thing is to learn how the software works and what you can do with it. If your not really into that it may not be for you.
 
Oakleyextreme said:
Hi and welcome.
I'm not as experience as some people on here when it comes to Z4 but I had a similar fault on my Honda S2000 with its EPS when it had a half flat battery, gave the battery boost charge and this reset the fault..
Just wondering if this could be the same as your car has not been used over winter.
Click to expand...

These cars do suffer with low/bad battery issues, I would also check this too as it seems strange how the steering has done this while being layed up. Try and give the battery a good charge.
 
@ ex4x4
Like Mr. Wilks said.

Here is a picture:

sticky1.jpg

In the red circle you can see the 2 srews - you have to open (after making a sign to mark the position of the red plate).
Then you have to move the red plate like Mr. Wilks said.

Number 4 ist the motor and 3 is the control unit.

Number 5 is too tight in number 8 - so the motor could not rotate.

If this don't helps, then the motor or the control unit has a problem.
 
he has a code. he needs to get that code first. There is no guarantee that he has sticky steering (that's the fix you're posting).
If he doesnt have sticky steering, it's best to leave that part alone imho.
Sticky steering is not a matter of the the wormgear (no5) not being able to rotate in the housing (no8). Its a matter of how much resistance that gear has in order for the torque sensor to read the amount of torque. Sticky steering doesnt give a code (well maybe if its a case of 'very sticky steering' :D ).
He now has no power steering at all. If he hardly can turn the wheel when the front wheels are on the ground, but he can turn them freely in the air, that's a clear sign that the EPS doesnt provide power at all. Why it doesnt do that.....probably only that code can give a clue.

These codes are in the 'eobd' realm, so descriptions on what that code means are not preset meanings within the obd2 standard (like PO301 is always detected misfire on cylinder one). this code will probably look something like 38AE or so. A custom code for which bmw has filled in a specific meaning. Or if there is a P code (or C code; P=powertrain, C=chassis, B=Body, not sure where steering is located) it will read something like P18D4. Everything above P0 or C0 etc is manufacturer specific.
Programs like INPA (or other BMW software) may give a description to that code. Generic code readers may not.
 
I had a simular problem recently ,after jacking the car up to do some maintance oil change etc the power steering light came on and no power steering ,i tried reading the code with the inpa software and got a message " no communication with module" so no code was given , not trusting my diagnosis i called an expert to check he came back with the same message.So i had no code .
So to cut a long story short i removed the whole eps unit from the vehicle and sent it to a steering specialist who repaired to control module attached to the column,i reinstalled and everything is ok
 
Thankyou all once again chaps for your thoughts and input, lots of avenues to explore......
I tested the battery at 11.9 volts after being stood for 24 hours and with engine running/alternator charge output is 14.2. Started car and left her tick over for 30 mins to give battery a good charging. - currently at 12.8 v with ignition off.
started car once again but EPS fault still present.
Ive had no prewarning of the issue - this is what is strange - as if something has just suddenly snapped or blown or has been removed by the Zed pixies over night - one minute fine - next minute game over.
I may have to find a indie in the North east to scan & rectify - but I hate being beat by cars :x
 
You must log in or register to reply here.
Back
Top Bottom