Technical EPS electric power steering faults

[koalar]

Oh well it has been like this for a couple of years but I think it's getting worse lately.

If I replace the torque sensor it has to be calibrated?

Pot luck

It usually close enough as long as you start with wheel pointing straight ahead, and you don't move it until your finished

 

[rafpanda]

Time to start watching some videos to learn how to change it then. Thanks @koalar

 

[A3jeroen]

On a bench (or kitchentable) splitting the column by removing the circlip makes it pretty easy to fit the sensor perfectly before removing the safety.
Worked for me perfectly. Although I have the full MES and green connector I recalibrated it after 6 months or so.

gr J

 

[RFollia]

Hi all, I am back again. Sorry for such a long time. Not an easy time, so far
-brake rebuild in a Range Classic.
-Disco 3. all fluids change, auto gearbox flush, diff+transfer box oil change. front air struts replacement, front disk brakes replacement, rear propshaft replacement. heater matrix unclogging.
-Lada niva. clutch +brake master cyl rebuild, new brake servo, heater hose replacement, dsitributor rebuild, ignition timing, full exhaust line replacement sorry
-And London Taxi TX1 beginning reassembly after rust removal....
Pending front caliper rebuild in a Santana...Yes, I'm going off topic,

So, back on the panda.
I built a new earth lead from scratch, using lead several gauge thicker than the stock one. Tested for continuity. Perfect. Tested old lead. no continuity, and when flexing made a cracking sound. So there was the culprit.
Assembled new lead. EPS worked! And works.
But, many times the light still is on even though EPS continues to work.
Only rarely, rarely, light is on and there is no assistance. Never happens on start up.
I mean. When cranking and after engine starting there is no EPS light and EPS works, light lights up after beginning to drive but EPS works.
If I want EPS light to switch off the only thing I have to do is to increase electrical load. I mean, switch on internal fan (A/C is not necessary), brake, switch on wipers or switch on headlamps (dipped beam is enough).
What is my conclusion? That maybe the alternator is bad. I mean, the workshop who fitted it fitted the wrong one (not the 14V 70A but some lesser 12V less amperes, which there exist for other panda versions). Went to that workshop to inquire but they just typed the fiat part no in the internet that linked to the 14V 70A version, but I'm still waiting to see the receipt of the alt that they bought and fitted to SWMBO's Panda)). As I have to take it (somewhere else) to change front tyres, when the car is on the lift I might be allowed to peek underneath and see what alt is fitted.
Will come back with more news if the "fleet" allows (only weekends and when it does not rain, and Northern Spain is more or less like Manchester...)
Best regards
Best regards

 

[koalar]

If I want EPS light to switch off the only thing I have to do is to increase electrical load. I mean, switch on internal fan (A/C is not necessary), brake, switch on wipers or switch on headlamps (dipped beam is enough).

It possible it the earth and it's finding an altenative path

It's quite common for say a rear indicator not to work unless the rear wiper is switched on

Have you taken these off and cleaned the terminals

This is where the EPS motor is earthed


I believe the EPS electronics is on the A pillar but never known it fail so would have to double check

 

[Mike1alike]

There are no 12V alternators
Try and take a peak and see what they fitted. The amperes, alt capacity matters. A lot.
But... I don't think improper alt is your problem. The problem is the torque sensor. It got damaged from running the car with that ground cable you've mentioned, that snapped and cracked. The sensor still has life in it but it's damaged, it's dying. New sensor will be the fix.

And for the alternator measure the voltage output to see how it's doing. And of course, read the label to see if it has enough amperes.

 

[koalar]

Is the steering light on the dash bright or dim, it's unusual for it to go out by switching on anything electrical, never seen or heard of this before


What is the voltage across the battery terminal, after the car hasn't been switched on for an hour or so

What is the voltage across the battery terminals with the car idling

What is the voltage across the battery terminals if you put on the main beam, blowers full, rear heated window, brake lights, reversing light, now raise the rev to over 2500 RPM does the voltage increase now

 

[koalar]

But... I don't think improper alt is your problem. The problem is the torque sensor. It got damaged from running the car with that ground cable you've mentioned, that snapped and cracked. The sensor still has life in it but it's damaged, it's dying. New sensor will be the fix.

Not sure how you came to the conclusion of a burnt out torque sensor

When the

EPS Work perfectly with the blowers on
EPS Works but with the light on with the blowers off

 

[Mike1alike]

Not sure how you came to the conclusion of a burnt out torque sensor

Well... I had the torque sensor malfunction.
Of course, the best is to set straight the electrics on the car first. Make sure there's good battery, good ground, good alternator and so. That is essential.
My impression was that running the car with problems on the electric side led to torque sensor malfunction. It didn't just cease to function, it took some time for it to get there but finally it did. The erratic behavior was kind of unpredictable. What was for sure was that cold and rainy weather made it worse. Other than that it would sometimes function ok, other times not.
So yes, maybe I jumped to conclusion.
As I've said, it's necessary to have the electric side in good working state.
But my experience is that once the EPS starts malfunctioning repeatedly, the torque sensor is going down. The errors are first rarely than increasingly more often.
I finally replaced the sensor after struggling with it for a while. I put a new one in 2018 or so. Never had any EPS errors since.

 

[jrkitching]

But my experience is that once the EPS starts malfunctioning repeatedly, the torque sensor is going down. The errors are first rarely than increasingly more often.
I finally replaced the sensor after struggling with it for a while.

I'd say that's broadly my experience too.

It may be that, as the torque sensor ages, the whole EPS system becomes more sensitive to any deficiencies in battery performance, and it's certainly true that a great many power steering issues can be rectified simply by replacing the battery and/or the earths.

My own car does still sometimes suffer from intermittent EPS faults, which generally put on the warning light and may or may not actually cause the EPS to disconnect. Usually, though not always, charging the battery properly fixes things, but sometimes the fault occurs when you'd least expect it, like at the end of a long journey. Restarting the car normally restores normal operation.

Replacing the torque sensor would quite possibly stop these failures, but it happens only rarely, perhaps every 2-3 months, and the failure is quite manageable once you're aware it might happen. So I've not bothered to go to the effort and expense of messing with it; it's been like this, essentially unchanged, for at least the last seven years. If it got markedly worse I'd do something about it, but the minor inconvenience of an occasional brief failure isn't worth the effort of stripping everything down.

So I'd say that for some folks with an older car and a very intermittent fault, the easiest fix might be to just learn to live with it.

 

[koalar]

and it's certainly true that a great many power steering issues can be rectified simply by replacing the battery and/or the earths.

Correct

Usually, though not always, charging the battery properly fixes things,

Must be telling you something

but sometimes the fault occurs when you'd least expect it, like at the end of a long journey. Restarting the car normally restores normal operation.

Replacing the torque sensor would quite possibly stop these failures, but it happens only rarely, perhaps every 2-3 months, and the failure is quite manageable once you're aware it might happen. So I've not bothered to go to the effort and expense of messing with it; it's been like this, essentially unchanged, for at least the last seven years. If it got markedly worse I'd do something about it, but the minor inconvenience of an occasional brief failure isn't worth the effort of stripping everything down.

So I'd say that for some folks with an older car and a very intermittent fault, the easiest fix might be to just learn to live with it.

I done dozens of Delphi power steering not just the fiat, and the system isn't the same as the more problematic Delphi used in the Punto 188

By comparison the torque sensor in the Panda rarely fails

When it does it's usually in one of a few particularly ways

It either feels funny or different turning one direction or the other

The steering moves on its own while the car is stationary

The steering always fails at a certain point often full lock but not always,, so full lock one direction fine, full lock the other and it cuts out

Out of the two confirmed cases, one was due to corrosion and the other looks like a strong possibility of the same

Of cause if you have the correct software you can just plot the data, a good torque sensor will be a nice and smooth plot, when turning the steering wheel. Faulty will show a spikes or flat line over any dead spots