My power steering red light intermittently comes on but I have never had the steering fail. I have read loads of threads especially the excellent guide. I have checked the battery and alternator and I suspect the alternator is just on the cusp of failing/under performing.

It starts fine and I have no alternator battery warning light. Below are the readings I have taken, can you advise if you think it is the alternator and if so I will get it swapped or do you think its actually something more serious popping the EPS light on?

Battery test
Cold first thing in morning 12.6v
Crank it and it does not go below 10v-11v

Alternator test
On tick over with no load I get 14.2v
On tick over with all lights on, main beam, blower on 4, rear demister on I get 12.65v to 12.78v (this is the reading I think is not so good as the guide says no lower than 13.8v and possibly the cause for the red light?)
Rev to 1500rpm on full load and it goes to 14v

Do you think that alternator is good or borderline or just faulty?

I have cleaned the earth up to the body, cleaned battery terminals, checked all connections are secure on alternator, belt tension.

Punto 2004 1.2 8v petrol.

Cheers

I have a couple of multiecuscan questions. If I buy the green lead and adaptor USB cable off Ebay for £20 will the free version of the software allow me to diagnose the error as I am getting nowhere on my own? Will I then have to buy the full version to reset the codes or reset the cars ECU if I have to replace any of the power steering assembly?

I am willing to do all the work myself as I had a quote of £40 just to read the code, before they even quote for parts and fitting. Id rather invest in the cables and software so I have it should I need it again.

To access power steering you need an OBD cable that supports CAN.
The problem of cheap Chinese OBDs is that they put a pesky resistor where it shouldn't be. Basically if you measure resistance between the CAN+ and CAN- pin you have to find and remove the resistor.

I did describe the procedure (unfortunately in Slovenian, but it has pics) on an another forum: https://s5tech.net/viewtopic.php?f=51&t=11201

I have the 1.2 16 V and you couldn't do anything with the free version, but I think for the 8 V it lets you access, not sure thou.

A bad alternator would turn off the steering as if the alternator doesn't work the car does turn off the steering, but it would also light up the battery light on the dashboard on peaks when the alternator wouldn't handle.

There is a far common error thou in power steering that is caused by bad solder on relays (although your model has it fixed already, not sure) or torque sensor.

Thanks Seba, my car has the newer relayless steering as it is the Mk2b (I believe). I am just sorting out the OBD now. I think its the ELM327 modified already so I can just use it once it arrives. I have downloaded the free multiecuscan software and will see how I get on, if I need to upgrade I will.

I just need to read the codes to see if its the EPS causing the issue. If so I will get a recon column and fit it.

:slayer:

Just measure the resistance between the CAN pins, if it shows something that is not in mega ohm (or nothing at all, i.e. infinite) range it won't work most likely.

If you can't measure resistance then you'll see when you'll try to connect to the engine, you'll get a CAN error, but engine codes will be read, because it will fall down to the non-CAN standard.

Got the ELM327 and full registered MultiECUScan and run the EPS diagnostics. I got the C1006 steering column position sensor error. I am going to check all the connectors by the EPS motor and ECU tomorrow and then recalibrate it.

Hopefully that does the trick otherwise its a new sensor or the whole column.

Connections on EPS checked, all reset and recalibrated and the light still remains. I do note the car has had a 2nd hand unit fitted before as you can see its grubby and the scrap yard marks are in place.

Looks like I need the refurb column, will source and fit.

Glad you are making progress with this. Multiecuscan is invaluable in faultfinding and worth every penny. A reconditioned colunm sounds like the way to go. The low voltage readings at idle with a full load is normal, as long as it picks up with the engine revs the alternator is OK.

Robert G8RPI.