Technical EPS failure - where is the EPS grounding cable located?

[Sprocket in a pocket]

Hello. I encountered a problem with EPS and I am trying to solve it myself. My 2012 Abarth 500 was kept in the garage during the winter time and was not driven for several months. When I tried to start it, the battery was dead. It showed only 4 volts. I charged the battery and the car started fine, but there were EPS and ESC lights on the dash. The dash told me to have the power steering checked and that the hill start is not working. OBD throws C1002-17 code, regarding torque position sensor. I thought maybe the old battery does not have what it takes to feed the EPS so I bought a new battery, but the problem persists.

After changing the battery, power steering came back on vehicle start a few times (it would last around 5-10 minutes until it was gone again). Now the steering wheel is hard at all times, won't even come back for a short period. So I started digging. First I went to the dealer, hoping that the EPS needs calibration. They charged me 62 euros for "diagnostics" just to read the code and tell me to get a new power steering column for 5000 euros Essentially they read the codes and did not even try to look deeper.

After some investigation I found some forum threads where people shared that very rarely the EPS column itself is the problem, rather it's usually some electrical problem like grounding (for example: https://www.fiatforum.com/threads/eps-electric-power-steering-faults.491623/post-4623018). It would make sense that some cables could've oxidized. The car was sitting in a wet garage for some time until I relocated it to a ventilated one.

Today I removed the main engine earthing strap and it is really "green and red", so I will be replacing that. I was wondering maybe someone knows where is the earth point for EPS itself? I would like to especially pay attention to that place and clean it well. I do not believe that my EPS column is at fault because the vehicle was just simply sitting still, not much of wheel turning was done during that period of time...

 

[the green vanper]

Hello,

They charged me 62 euros for "diagnostics" just to read the code and tell me to get a new power steering column for 5000 euros

Typical for a FIAT dealer... I don't even bother anymore. However they provided me the FIAT CODE number free of charge

As for the problem, attached a couple of docs that might be helpful diagnosing the problem.

The earth cables tend to rot on the inside, so it is hard to see at first glance. The earth points also can rust around which causes a very high resistance on the area.

I'm replacing those earth straps with good quality copper (not CCA) welding cables, adding connectors on both ends and heatshrink on top of the connection:

A local welding store will sell you a cable cut to length and also probably will be able to crimp the terminals on.

It will definitely last longer than the factory ones.

Get yourself a license for MultiEcuScan or AlfaOBD. And a proper interface (I'm using viaken's STN1170, it's dedicated to FIATs and Fords, connects to all FIAT modules, even allows key programming). Details on the multiecuscan.net website.

You won't need the dealership anymore

Colour coding table:

The earths/power supply docs do not cover the Dualogic nor Xenons. If you have them, let me know, I will generate and add the files tomorrow evening.
The ESP doc covers the cars produced until September 2014.

 

[Sprocket in a pocket]

Thanks for the info. Today I bought and installed a new grounding cable (chassis to transmission). The power steering was still not working. I connected with mutliecuscan and ran EPS calibration reset + calibration. After starting the engine, it seemed that power steering was back, but after turning the wheel slightly, it threw and error again and the steering was hard again. I was monitoring live parameters and the position of the steering wheel was being registered until the error. Then the wheel angle sensor started showing 0. Could it be that the torque sensor is truly cooked? Why would it then register angle until the EPS error code?

 

[Sprocket in a pocket]

Hello,



Typical for a FIAT dealer... I don't even bother anymore. However they provided me the FIAT CODE number free of charge

As for the problem, attached a couple of docs that might be helpful diagnosing the problem.

The earth cables tend to rot on the inside, so it is hard to see at first glance. The earth points also can rust around which causes a very high resistance on the area.

I'm replacing those earth straps with good quality copper (not CCA) welding cables, adding connectors on both ends and heatshrink on top of the connection:

View attachment 462962

A local welding store will sell you a cable cut to length and also probably will be able to crimp the terminals on.

It will definitely last longer than the factory ones.

Get yourself a license for MultiEcuScan or AlfaOBD. And a proper interface (I'm using viaken's STN1170, it's dedicated to FIATs and Fords, connects to all FIAT modules, even allows key programming). Details on the multiecuscan.net website.

You won't need the dealership anymore

Colour coding table:

View attachment 462961


The earths/power supply docs do not cover the Dualogic nor Xenons. If you have them, let me know, I will generate and add the files tomorrow evening.
The ESP doc covers the cars produced until September 2014.

Hi, I can't find a way how to PM you. Could you give me your contacts so I could reach out to you about ordering a new torque position sensor?

 

[the green vanper]

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