Technical Steering goes left at low speed on my Seicento Sporting

[centsei]

Hello all!

It's been a few weeks with my new 1999 Seicento Sporting and besides some small issues I am working on, the one that worries me the most is one about the steering.

So it happens that, at very low speeds (<25 kph) the steering goes left. Specially at speeds close to 0, it can make more than half a turn on the steering wheel. It feels also much more easy to turn left, and harder to turn right at those low speeds. However, when driving at higher speeds it goes straight and the feeling is similar whether turning right or left.

I know that some models have a electric power steering. How can I know if mine is one of those? Do you think it might be an issue with that, if equipped? Or should I check the steering rack? I've changed the tyres left-right and it continued, so I guess it has nothing to do with them.

Thanks in advance for your help!

 

[Greasytrucker]

Could it be top strut mount bearing on one side starting to seize? Any noise if you turn the steering on the spot?

 

[FiatMatt94]

Hi & welcome, if it pulls to the left slightly maybe check things like top & bottom ball joints, lower arm bushes, anti roll bar bushes for wear & make sure the 2 strut bolts are fully tightened etc. As for power steering as far as I'm aware all Sporting models came with power steering as standard, I think on SX's it was optional as my SX has power steering it was only the S model that didn't get power steering at all. When you turn the ignition on there will be a red power steering light which goes out once started. The system on the Seicento's is very simple as it's the predecessor to the more common Dual Dive systems as from MK2 Punto onwards, all the Seicento system consists of is a electric motor at the top of the column behind the cowling & an ECU in the passenger footwell. As with the dual drive systems the Seicento system relies on a decent battery for the system to work efficiently so check that your battery is good with decent voltage along with checking/cleaning earths etc

 

[centsei]

Thanks for the answers!

Could it be top strut mount bearing on one side starting to seize? Any noise if you turn the steering on the spot?

There's no noise when turning the steering. At a first sight it didn't seem to be the bearings, but I'll double check that.

Hi & welcome, if it pulls to the left slightly maybe check things like top & bottom ball joints, lower arm bushes, anti roll bar bushes for wear & make sure the 2 strut bolts are fully tightened etc. As for power steering as far as I'm aware all Sporting models came with power steering as standard, I think on SX's it was optional as my SX has power steering it was only the S model that didn't get power steering at all. When you turn the ignition on there will be a red power steering light which goes out once started. The system on the Seicento's is very simple as it's the predecessor to the more common Dual Dive systems as from MK2 Punto onwards, all the Seicento system consists of is a electric motor at the top of the column behind the cowling & an ECU in the passenger footwell. As with the dual drive systems the Seicento system relies on a decent battery for the system to work efficiently so check that your battery is good with decent voltage along with checking/cleaning earths etc

Since it goes fine when I go at "higher" speeds, I guessed it had nothing to do with ball joints or anything else there, but I'll follow your recommendations and double check those as well.
Thanks for the info about power steering. I'll check if I can see the light on the dashboard. I was inclined to think that the issue might come from there because it only happens at low speeds, which I guess is when the power steering acts.

 

[centsei]

Hi all,
I've reviewed a few things on the car.

1. The front left tyre had a bit less pressure than the front right, so I've put them at the same pressure and tried it again. It looks like it does it less than before, but it's still happening.
2. The top strut mount bearings look good and tightened on both sides.
3. The left steering tension rod head looks a bit damaged, but I don't feel this should be the reason. See picture.
4. The steering wheel moves to the left alone when starting the engine, with the wheels in the straight position. See video.

I am very new into car mechanics and learning by doing (and by reading this forum! ), so sorry if I am saying stupid things or asking silly questions. But seeing this behavior, which I don't think is normal, is what makes me wonder if the issue might come from the electric power steering part. Could it be that?
What do you think?

Thanks for your answers and your patience!

Steering tension rod head:

Video of the steering wheel moving to the left when starting the engine:

 

[FiatMatt94]

The track rod end probably isn't helping as the dust cover is split so all sorts of crud could have got in there damaging the ball joint, quite a cheap fix & very easy to do, however after watching the video of the steering doing this when stationary it would point me towards either the motor in the column or the ECU for the power steering, the steering rack itself isn't electronic, it's just a regular rack & pinion system, the only electrical part about the column is the motor at the top underneath the cowling. If this were my car I'd be looking into getting rid of the power steering completely as I have read that it can be converted by changing the column for one from a basic S model which didn't have power steering & removing the PAS ECU with it, although the racks for the power steering & non power steering models have different parts numbers I doubt they'd be any different as they are both mechanical rack & pinion, also Fiat have a habit of having multiple parts numbers for the same parts. Or perhaps if you want to try something that wouldn't cost anything you could try disconnecting the power steering by removing the fuse from the small fuse box behind the battery, see how it feels in terms of heaviness which I doubt it'd be really heavy being how tiny & light the car is & just drive it about with no power steering.

 

[centsei]

Hi FiatMatt94, thanks for your answer.

I've already ordered a couple of track rod heads to change them and see if it improves. However, while I am waiting for the delivery, I would like to check the option of disconnecting the power steering by removing the fuse. However, I didn't find in the owner's manual which is that fuse.

I don't have the manual here now (I can only work on the car on weekends, and the manual is there) but if I am not wrong there were two or three different fuses next to the battery. Also, I am super newbie on car mechanics and I am a bit afraid on "breaking something". So any indication on which might this fuse be, will be very appreciated.

Thanks!

 

[FiatMatt94]

Where the battery is located in the engine bay there is a fuse box with I think 4 fuses, behind that fuse box there is another 2 fuses, the power steering fuse is the one on the left with a steering wheel symbol on the cover, access can be quite tight & fiddly if you have quite big hands like myself maybe you could take the fuse out & clean it as it can get quite mucky behind there & also when it rains water runs down around that area also so could also maybe be a corroded connection, if you put the fuse back in afterwards & it hasn't worked then remove the fuse & see if it is drivable without power steering, it might not work but it's worth a try.

 

[cinquecentos 4 life]

Just bought a 1999 seicento sporting yesterday with the exact same steering issue pulls left on startup, please let us know how you get on, I will also try the fuse.

 

[Mike1alike]

The steering pulling left issue is caused by faulty Steering Angle Sensor. That is located in the column and it's an easy job to replace it. After replacing it you need to calibrate it using MultiEcuScan.
On the older models (prior to 2002) the electrical motor on the steering has 2 relays inside that wear out in time and that is creating the problem. Replacing those can be the fix if the angle sensor is not damaged.

To disconnect the power steering, if you cannot get to the fuse, you can do it by disconnecting the angle sensor and motor cable from the steering ECU.

 

[cinquecentos 4 life]

The steering pulling left issue is caused by faulty Steering Angle Sensor. That is located in the column and it's an easy job to replace it. After replacing it you need to calibrate it using MultiEcuScan.
On the older models (prior to 2002) the electrical motor on the steering has 2 relays inside that wear out in time and that is creating the problem. Replacing those can be the fix if the angle sensor is not damaged.

To disconnect the power steering, if you cannot get to the fuse, you can do it by disconnecting the angle sensor and motor cable from the steering ECU.

So are you saying pre 2002 no calibration is needed ?

 

[Mike1alike]

Nooo, I'm not saying that. Calibration is needed on every model if you put new sensor on. The difference pre/post 2002 is on the electronic steering motor. Pre had those 2 relays inside that gave a lot of problems at their time. Because they would get toasted pretty quick, sort of the soft spot of EPS, and then the EPS wouldn't work properly. Post 2002 Fiat discovered that soft spot and came with new design for that motor, without the relays. I never hear of faulty motor since. But, apparently the electrical stress is being taken by the steering angle sensor and now replacing that is the fix.
If the electrical side of the car is being taken care of and if it's working properly, the EPS works just fine for many years. If there are problems on the electric, the EPS is sensitive and will brake. So if you come to the point you need to replace the sensor, it's better to also take a look at the electrical side, make sure there are no shortcuts, the battery and alternator are good, ground cable is good.

 

[Mike1alike]

Here you can see images with the relays, on a Punto:

 

[centsei]

I think I can't do this on my own

 

[FiatMatt94]

I think I might be onto something as ever since I've had my Seicento I've also had little gremlins in the steering where it felt more heavy turning right than left, I pulled the fuse out & gave it another clean but whilst I was in there I decided to see where the lead coming from the power steering fuse goes to, part of it tags off & goes to the positive battery terminal but if you follow the wires along you eventually end up at the positive output on the alternator in which mine was very corroded, so I cleaned it all up with a wire brush then cleaned up the 2 way connectors on the positive battery terminal & fingers crossed when I took it for a drive the steering was working as it should so I seem to have solved the issue that has plagued the Seicento in the 9 months I've owned her, this could be worth a try with your Seicento @centsei as it appears to have made my steering better, I'm going to take it for a proper drive tomorrow to see if it's definitely good, also I need to get new studs for the 2 way connector on the battery terminal as I'm a bit heavy handed & snapped it luckily I found another 10mm nut & bolt to use temporarily but it's very slightly longer than the original one so would rather get 2 new ones the correct size. Only thing is now where the system seems to be working properly it feels a little over assisted probably because I'm used to old cars & haven't owned many cars with power steering.

 

[centsei]

Thanks @FiatMatt94!
I'll see if I can find some time this weekend to look at this. Lots of things to do in my list!

 

[FiatMatt94]

I also removed the negative battery lead, cleaned up what I could & then reinstalled it which has improved it hugely as it only did it once & then behaved itself the entire time when I took it for a long drive, before it was doing it pretty much all the time so I think for a few pounds I'll replace the negative battery lead with a nice new one as the one currently on the car has corrosion underneath the rubber covering, it's still on it's original lead which is 25 years old so I think she now deserves a new one & then I think that'll be problem fully solved , she's definitely much more fun now in the corners & roundabouts .