Hi, 

 

I have a 2007 Fabia with the 1.2 engine. It has an intermittent fault which happens as follows: 

 

The big red '!' warning light on the dashboard comes on, and the yellow 'PAS fault' steering wheel warning light comes on at the same time. They stay on briefly (a second, possibly less), the dashboard then resets (clock resets to 12.00 and the odometer resets to 0) and all the warning lights go out. This happens while the car is running and it continues to run fine - if you are not looking at the dashboard then you'd not know anything was wrong. 

 

Occasionally things are slightly different; sometimes the yellow 'PAS fault' light stays on and the power steering stops working. Everything else carries on working fine but the steering gets very heavy. Turning the car off and on again resets everything and it's all back to normal (other than having to re set the time on the clock). 

 

This only happens at low speeds; typically when in 1st or 2nd gear and trundling around town. It never happens at speed. 

 

I've looked at the diagnostic codes in the system using a scan tool and it tells me it has fault code 01288, which it calls "Short to ground Terminal 30 Steering Assist". Googling "01288 Fabia" turns up several results, many of which ultimately direct me to here: 

 

http://wiki.ross-tech.com/wiki/index.php/01288

 

However I don't have the fault 'Signal too high' or 'Signal too low', rather I am told that it is a 'short to ground'. 

 

I've not done much to investigate this but thought I'd post on here to see if anyone has any idea where I should start looking. I'm guessing that the car has an electric power steering pump (i.e. hydraulic power steering but with the pump driven by an electric motor rather than a belt from the crankshaft) and there is a wiring fault somewhere. The fault is intermittent and effectively briefly shorts out the electrical system causing everything to reset. Is this a fair assumption? If so then are there any points where such a short to ground could occur? Where would you start looking for it? I presume it's a chafed wire or something like that. 

 

FWIW the fault started after I topped up the power steering reservoir (which involved removing the battery and quite a lot of associated plastic gubbins around it.) I wonder if I knocked something then but I've subsequently removed the battery and replaced it with a spare which I had lying around and had a fairly good look at all the various bits of wiring around there and couldn't see anything amiss. 

 

All suggestions welcome before I start dismantling stuff - thanks. 

Simple, quick test to do before anything else: https://www.briskoda.net/forums/topic/401778-battery-light-and-associated-problems/

 

Battery earth lead/strap. Make sure it is making good contact between the battery and the body as these can get dirty causing the electronics to get the screaming heebie-jeebies and taking the huff. Mine did it with PAS, ABS, clock, and stereo problems.

 

Hope this helps.

It will be as Wino suggests or a bad connection to the pump unit, that should not pull down the other controllers though.

 

Short to ground actually means voltage too low, it means the voltage has dropped too low and will either be the charging system as Wino has linked to (my vote) or a high resistance/damaged cable, it could of course be an intermittent short to earth but the conditions when it occurs are high current draw low (or no) charging voltage.

I'd agree that the first thing to do is to check the battery terminals, and then the earth connections.

Short to ground is usually the fault detected when water interferes with the current path, this can be due to condensation buildup in the brushless motor circuitry or in the power connector or even a cracked fuse.

Edited 31 December, 20214 yr by sepulchrave

Chaps, 

 

Thanks. This is all tremendously helpful. Sorry for the slow reply; New Year and other things have taken their slices of time. 

 

In turn: 

 

Wino,:thanks. The battery light does as it should; it comes on with the ignition and goes off a second or two after the engine has been started. 

 

AP: thanks, I'll check the battery earth strap - nice and simple. (By 'check' I'll probably disconnect it, clean the contact at the bodywork end and re-attach it nice and securely.) 

 

JR: thanks. Bad connection to the pump unit sounds possible - where is the pump unit? Interesting point about this actually being voltage too low. It's probably clear that we are looking at an electrical connection fault somewhere, the question is where? 

 

KenO'N: thanks, I'll do those things. Battery terminals have been checked already. 

 

sepuchrave: interesting, thank you. Where is the brushless motor circuitry? And by 'power connector' I presume you mean the connector to the power steering pump motor? Cracked fuse? I'll change the one for the power steering - is this what you mean? 

 

It's possibly worth mentioning that this is an infrequent problem - it happens every ten days or two weeks or so. It happened this morning quite dramatically and the power steering stopped working, but turning the engine off and re-starting brought everything back as it should be. 

 

Thanks again for your input. 

Steering pump/reservoir is shown in the yellow box here. Access is good with front bumper removed.

 

The main permanent power connector is the one with the two fat wires in the middle, red goes up to one of the strip fuses in the fuseholder above battery, brown earth wire goes to the stud arrowed in brown.

 

Wino, 

 

Many thanks for this. It looks like the first step will be to have a good look at the plug on top of the pump and see what's going on there, and tracing some wiring around to make sure it's OK. I notice that the pump is right underneath the battery, so it's quite possible that I disturbed something when I removed it to fill up the power steering fluid reservoir. I'm hoping that access is possible without needing to take the bumper off as that's getting into a moderately big job but I'll see what's what later on this week when I get a chance to look at it. 

 

Thanks again for your help. I'll keep this thread updated. 

Update: I took the battery and battery tray out yesterday to have a look to see what's going on with this pump. There was a conduit of cables running under the tray (more later) and I discovered that I could access the plugs on the top of the pump fairly well if I removed the black plastic trim from the front bumper (I suspect that this would hold a fog light or driving light on a higher-spec model. As it was it just pulled out, nice and easy). 

 

And I saw nothing amiss. All seemed to be as it should, not cables were frayed or worn or broken, all three plugs on the pump looked to be clipped in fine. I unclipped them and re-clipped them to make sure that they were indeed as they should be, and I also removed and cleaned the connection on the end of the earth strap and did the same to an earth point on the body just above the steering pump motor. Has it made any difference? I don't know; the light didn't come on when I turned the engine on afterwards but it always was an intermittent problem so I wasn't expecting it to. 

 

One Q: the wiring in the conduit looked somewhat ramshackle, with black plastic tape around it. It also had a peculiar looking connection that looked like a piece of clear heat shrink about 2 inches long, which appeared to connect a heavy gauge brown/black wire to a much lighter gauge wire of the same colour. Is this from the factory or has someone else been here before me? Here are some photos. 

 

 

Thanks again for your help. Time will tell whether this has made the problem go away. 

I expect all that is exactly as it was when it left the factory.

If it hasn't already been said, steering pump cutting out is often due to a weak or dying battery. The peak current required when turning at stationary or low speeds is higher than the alternator provides at low rpm. Requires a healthy battery, if the voltage dips too low, the pump will shut off.

Wino, thanks. It just looked a bit ... scrappy. The old and curled insulation tape didn't help. 

 

xman, thanks. I actually changed the battery when it first started exhibiting the problem; not for the reason you said but more that I thought it may have a poor connection somewhere, and I had a spare (and big) battery lying around. The change of battery made no difference, but good thinking anyway! 

 

The problem has yet to re-appear since doing things last week but it always was intermittent. Carry on watching this space. 

Update: The problem still hasn't re-appeared. The car has worked faultlessly since I took things apart and cleaned the terminals up. Given that that was mid-January and we're now early March then I think I'm going to consider it 'fixed', which is very satisfying! Many thanks to everyone for your help.