E92 steering assistance failure

[Jub3box]

Hi all,

I'm hoping to get some help on the problem I have with my E92 325i. The car seems to have picked up a steering assistance problem which is indicated as such on the idrive screen along with a yellow steering wheel + exclamation mark symbol (esclamation mark is on the right of the steering symbol) on the dash. This is an intermittent problem which only seems to happen upon full lock steering and turning over bumps in the road. When it happens the car throws up the 'steering assistance failure' message on idrive screen along with the steering symbol on dash and to go with it, the steering also stiffens up as if there is loss of power steering. I tried to do my own search on this but I couldn't find anything relating to this.

I guess my question is if anyone has experienced a problem like this if so, how did you fix it and what was the problem?

any help is much appreciated, thanks in advance!

[bmwdirtracer]

Step 1 is to take the car to a BMW specialist shop, where they can converse with all the computers. When you get a warning like that, codes are stored in one or more computers, and these codes are the clues needed to diagnose your issue.

Be aware that we need more information than E92 325. Either the last 7 digits of your VIN, or month, year, and equipment....

[Jub3box]

Hi, thank you for prompt response. Apologies, I'm new to the forum so was unsure of exactly what information I should put up. It's Dec 2008, unsure of equipment other than it's a standard Msport with an N53 and ZF transmition, I hope this helps? I should have put this on me initial post but I did get it diagnosed and it returned the following:

63f5 - EPS reduction servo power dur to supply voltage.
A0B6 - CAS selector lever Interlock

again appreciate the help.

[Jub3box]

Hi can anyone offer any advice on this as I'm at a loss. The steering is fine most of the time it's just when I turn corners or go over bumps when turning it brings up the error message. Do the above diagnostic codes mean anything to anyone?

[bmwdirtracer]

It would seem that your Electronic Power Steering is not getting correct voltage. Do you have any voltage codes in other computers? The ABS/DSC and the SRS (airbag) systems will often be among the first to show voltage supply issues.

Remember that every power (voltage) supply issue has two equally important factors: Power, and Ground.

It's likely that you're going to need serious electronic diagnostics to solve this. First step will be to pull up the wiring diagrams for the EPS, and also check main power and ground connections.

Do you know if your car has ever had the Junction Box Electronics service action / recall done?

It might be worth a visit to the dealership, to ask whether your car has any outstanding recalls or service actions, especially in view of the EPS issue.

[Jub3box]

Hi,
I went to dealership today and they said there are no recall markers for my VIN number. It has had a recall for injectors and coil pack but nothing for EPS.

No other voltage codes other than the EPS one, the only other thing that came up on diagnostics was A0B6 CAS selector interlock?

its a weird issue because it didn't do it all day yesterday and was going great this morning. Then all of a sudden, it came back this afternoon when I started up after leaving it for a couple hours. The error message came on as soon as I turned the engine on (never done this before, it only did it when I turned corners) and it stayed on for A couple of minutes before it cleared (only came on for a couple seconds when it did it before) the steering was heavy all this time and then went back to normal as soon as the error cleared.. As you say, it does seem to be an electrical issue as I'm not getting any noises from the rack or anything.

Could it be a coding issue? If so, are the dealership the only people who can re-code?

Again, thank you so much for your time.

[bmwdirtracer]

The dealership is certainly not the only place that can recode or program your car. The indy shop where I work has the very same coding and programming capabilities as the dealership.....because we have ISTA at a level within a month of the dealership. (Thanks to a a magnificent friend at this forum.....He'll identify himself when he wants to....)

Now, you've identified yourself as being from Newcastle.....That's not really fair.....England? Australia? USA? Newcastle upon Tyne?

I'll assume that you asked the dealership to diagnose your steering issue? What did they tell you? (You paid a good price for their diagnosis, and they have great tools, let's pay attention.)

[WadiM3]

Newcastle from the UK I'd assume!

[bmwdirtracer]

Yeah, but we've got a few here, too, Seems they do down under, too. Brits seemed to get around a bit, huh????

[Jub3box]

I'm from Newcastle upon Tyne, UK ��
I haven't asked dealership to carry out diagnosis yet, truth be told, purely because they tend to scare the sh*t outta you when the problem can be fixed for fraction of the price and or for nothing!. I remember taking my old E46 to them to have two keys reprogrammed and they said it'd cost £1100 to do it, I came back home, googled it and done it for nothing in 30 seconds!

I wanted to hopefully find someone on here who's had a similar problem and learn from their experience in how they went about fixing it.

If dealers is my only option, then I would have to bite the bullet and take it there.

ps I was thinking about taking the fuse out for the power assistance steering as a process of elimination. I figure by doing this atleast I can underpin that it is indeed 100% an electrical fault as if it still does it (with the power steering disarmed) it may be something mechanical.

thoughts on this?

[bmwdirtracer]

I don't know what the dealership was thinking, when they told you that reprogramming keys was 1100 pounds. Do be aware, though, that "reprogramming" is a whole lot different than initiating the remote functions. Perhaps, just perhaps, they were quoting for 2 new keys and a new EWS module. I don't know, but maybe there was a misunderstanding of what was needed?

On to the subject at hand....
If you unplug the fuse which gives power to the power assist, you're going to lose all assist.

Now, I can only look at wiring diagrams for LHDrive cars, sorry. But much should remain the same.

The EPS uses:
Fuse 49, 40 amps, at the Junction Box inside the cabin
Fuse 77, 10 amps, at the Junction box
Fuse 103, 100 amps, at the rear fuse box.

Grounds show as
X1703 "Below LF strut tower"
and
X165 "Left side of engine compartment"


Again, left might just become right, on a RHD car.

[TonyAngel]

Jub, I believe that the point bmwdirtracer is trying to make is that you could be suffering from one or more problems that are causing your loss of power steering. You are actually lucky in the sense that your car's system is returning a fault code. Knowing what those faults codes are can greatly narrow down the possibilities. I believe that what is being suggested is that you take it to a dealership so that they can run a scan, give you a diagnosis and give you an estimate of repair costs. You can then walk out of the dealership with the diagnosis and begin sorting out the problem yourself.

As was mentioned above, it could be something to do with either the positive or negative connections. Both are needed to flow current. On the other hand, if there is a motor (in the traditional sense) in the system, I've seen worn motors do some whacky things. Like getting bumped and not working only to start working again when you hit them with a hammer. Worn internal parts can cause contacts inside of the motor to lose contact and a jar (hitting bumps) can make them start working again, or quit working.

Whatever the case may be, knowing what codes are stored in the car's system will go a long way to helping diagnose the problem.

On another note, if you are going to own an out of warranty BMW and want to do, at least some, repairs yourself, you should invest in a scan tool. Many can be had for under $150. Plug it in and it will, more often than not, tell you what your problem is.

[Gazza91]

Hello,

Did you get anywhere with this. I seem to be having a similar issue. And my warranty company has gone bust

I do not have any error codes except the power assist fault on the screen. I have had it plugged in and for some reason the computer cannot connect with the active steering but can connect with everything else.

Any thoughts?

Cheers

Gareth