Technical Steering issue

[Marco92spv]

Hello everyone, I hope someone has an answer to my question.
Occasionally, the steering wheel on my fiat 500 does not return all the way back to the center. It only happens for, lets say about 30 seconds, a minute at most, then returns to function as normal. It doesn't seem to be a power steering issue as I can steel turn left or right with minimal effort, and no steering warning light on the dash. I have noticed that in most cases it occurs after turning left on a slight slope. About a year ago I decided to replace shock absorbers, springs and strut top mounts, as they were in really bad condition. Although it drives much more comfortably, the issue comes back for few seconds, maybe once every 2 weeks. I also had tyres replaced, and of course wheel alignment done. The car goes dead straight in normal conditions, unless the issue reappears. I can't get my head around it. Has anybody experienced this before, or has a vague idea of what could possibly causing this?

Many thanks

Marco

 

[Mike1alike]

The EPS is very sensitive to voltage. It doesn't like low voltage and for good reason, because that kills it.
So you should start checking the charging system, battery and cables. Make sure everything is in order. Pay special attention to the ground cable, usually it is the one that starts this bad journey for the EPS.
You should connect to steering module with MES and see if there are any stored errors, even if the light on dash didn't pop on.
When this behavior happens, usually the torque steering sensor on the column started to fail. It can go on for couple of years with errors coming on more often and in the end the system won't work at all.
New sensor is the best fix. It is pretty easy to replace, just need to mind not to put pressure on sensor when doing it because it is sensible and can damage easily.

 

[Marco92spv]

Thank you Mike, I will definitely look into it. Never thought it could be an electric issue, as mentioned before it happens in certain conditions, which made me believe it could be more of a mechanical thing. Few times it happened after turning left on a slope at same crossing in my area.
So where's the EPS ground cable located? I've read it has nothing to do with earth strap, which by the way I also have replaced a couple of years ago for other reasons

Thanks again

 

[Mike1alike]

Marco, with your earth strap already replaced, it looks more like the torque sensor itself could be the issue.
It’s the one that feeds the EPS ECU your steering input. A fault there can cause intermittent assistance or warnings, especially in certain maneuvers or slopes.
Check live data with Multiecuscan (steering torque/angle values) while turning - it usually points you right at the sensor or the EPS ECU reaction.

 

[John202020]

The steering rack is not power assisted it's a simple basic rack, that could indicate a mechanical issue? Re check the front suspension components, track rod ends etc?