Steering motor ecu issues! Help please

[Sevy7]

Problem. 3.02005 Z4 manual.

Intermittent Power steering light on

Solution give to garage to repair. Burton Motor Workshop have always worked by. Mw and know BMW. Very well.
Info. Garage discovers no signal from Ecu/ motor removes it and discovers it has been repaired at the renowned place for these repairs with a lifetime warranty
Garage removes motor and sends back for lifetime warranty work. Said place claims there's no fault found but says it carried out repair again.
Garage discusses issue and asks for conformation this won't re-occur, they confirm, fits motor and intermittent problem still there.
Now 14 hrs of labour later motor/ecu is going back again.
What would you do?
I thought these guys were the top people ?
Any advice please. My Z has been sat in the garage weeks now and summers nearly over
What's involved with converting to hydraulic? Is there anyone who can do it for me? .
It's a Z4 forum car

 

[enuff_zed]

I would suggest that if they found no fault then there was no fault with it (at the time they checked it)
The repair involves changing relays on the circuit board I believe.
They do run them up on a rig of some sort to check them so hopefully they would have left it long enough for an intermittent fault to show itself.
I've personally used them 5 times and know of three others who have done the same, with me helping over the phone.

Can the garage prove that the fault is being caused by the motor and not by a signal to or from it?

What I would query is the 14 hours of labour?
Even allowing for removal of seat and steering wheel I can get the motor out in an hour tops, and refit in the same time, usually slightly quicker.
Is the garage faffing about doing the full column removal?

 

[Rockhopper]

Sounds like the garage isn’t really that familiar with BMW electrical systems.

 

[Sevy7]

Please do enlighten me rockhooper. They've been a very well regarded BMW independant for many years. So where do you suggest the fault is?

 

[Rockhopper]

I’ve no idea, I don’t run a garage. But you’d hope someone who did run a garage that’s a “well regarded BMW independent for many years” would have a clue. Sounds like they don’t.

 

[Sevy7]

So your statement is unhelpful.
They do have a clue and the fault is still the same. Intermittent signal from the Ecu and the motor can be hear clicking.
Thanks for the cristisim that wasn't really any help in this situation.

 

[Sevy7]

I would suggest that if they found no fault then there was no fault with it (at the time they checked it)
The repair involves changing relays on the circuit board I believe.
They do run them up on a rig of some sort to check them so hopefully they would have left it long enough for an intermittent fault to show itself.
I've personally used them 5 times and know of three others who have done the same, with me helping over the phone.

Can the garage prove that the fault is being caused by the motor and not by a signal to or from it?

What I would query is the 14 hours of labour?
Even allowing for removal of seat and steering wheel I can get the motor out in an hour tops, and refit in the same time, usually slightly quicker.
Is the garage faffing about doing the full column removal?

Thanks pal. They had it a day and that was all.
You can hear a relay or something clicking when the fault appears. The company told the garage that they couldn't reproduce.. When the it was all refitted everything worked fine for 2 weeks. I was on holiday so I couldn't collect the vehicle. I returned called up and whilst moving the car that week it appeared again. The garage owner is engaging but it's weird how this was documented to have been repaired less than 2 years ago and has now gone again and they claim to have repaired it again yet the fault re appeared.
It would be great to know how to do the job. In an hour please. I would have took it out myself but I stuck the car in for an mot and when we discovered it was under warranty from a previous repair I went with letting the garage do the work. I have the orginal reciept for the firar repair.

 

[smorris_12]

My take is that either the refurbishers have fixed a standard problem and there's another intermittent one underlying it, or that the fault is somewhere else (pushed in pin in the loom connector, damaged wire or something like that.)

I suspect a new/second hand module is the next step.

 

[enuff_zed]

Another EPS motor can be fitted without any need for coding.
It won't come with any warranty, but may at least prove the problem.
If you document everything exactly, then are able to prove there IS an issue with the motor, you may get more luck with the 'company'.

When exactly does it happen? I recently changed a complete column that had a similar issue, but that only happened at low speeds and when turning the wheel to the left. Turned out to be the torque sensor inside the column. But that DID show a code.

 

[enuff_zed]

Another thought.................. have they checked the live data from the steering angle sensor? Should show movement from -540 to +540 degrees. If it has a glitch it will put the steering light on.

 

[Joez4]

Check your alternator and voltage regulator to see if your getting over 14v to the battery when the car is running, might not be the issue but when my eps module failed I took it out and sent it off for repair and on my test drive with it back in I had complete electrical failure from a failed voltage regulator that was intermittently putting out less than 13 volts, when i changed the alternator i put the old voltage regulator in and only got 12v and got codes for bsd and generator, i suspect in my case that they both failed at the same time and maybe a voltage spike took out the eps module i might be clutching at straws and maybe it was a coincidence that they failed together but worth a try.

 

[Sevy7]

My take is that either the refurbishers have fixed a standard problem and there's another intermittent one underlying it, or that the fault is somewhere else (pushed in pin in the loom connector, damaged wire or something like that.)

I suspect a new/second hand module is the next step.

Agreed. I'm going to try another module if no joy on the next return

 

[portculisz4]

I had similar problem, power steering failed with 'no communication' to the steering EPS. Sent motor off for a repair to the well known place mentioned in a previous thread (£295), EPS motor returned within 4 days, worked once properly and then only intermittently. Sent motor back again but they said the unit was unrepairable (did refund me the money) and would have to be replaced. My plan was hydraulic conversion this year but family circumstances will delay this to 2024 so to keep car running I turned to ebay for a replacement motor and was lucky to find a good one from a Z4 owner who just converted their steering. Motor installed and working, car now back on the road in the meantime.
Now with duff motor on the bench I did an autopsy on it, it appears for the repair they prise off the plastic rectangular lid exposing the motor ECU but for the life of me, I cannot see any repair work on or near the circuit board. Has anyone any idea exactly what the repair is ??

 

[enuff_zed]

I had similar problem, power steering failed with 'no communication' to the steering EPS. Sent motor off for a repair to the well known place mentioned in a previous thread (£295), EPS motor returned within 4 days, worked once properly and then only intermittently. Sent motor back again but they said the unit was unrepairable (did refund me the money) and would have to be replaced. My plan was hydraulic conversion this year but family circumstances will delay this to 2024 so to keep car running I turned to ebay for a replacement motor and was lucky to find a good one from a Z4 owner who just converted their steering. Motor installed and working, car now back on the road in the meantime.
Now with duff motor on the bench I did an autopsy on it, it appears for the repair they prise off the plastic rectangular lid exposing the motor ECU but for the life of me, I cannot see any repair work on or near the circuit board. Has anyone any idea exactly what the repair is ??

I was told it was 'relays' on the circuit board. Similar issue to the GM5 problems?
I would assume that a professional would be able to remove and replace these without much evidence they had been there?

 

[Sevy7]

So an update.
The Ecu is now goï g back a second time as the reputable company has agreed to pay the labour to remove and to re examine. A manger is personally supervising the repair.
A full loom pin check has been carried out. It is definitely the Ecu relays.