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I recommend to let your garage cancel the error, it is probably related to your battery since the PAS might have communicated wrongly when it didn't receive enough power. If it comes back it is more worrysome. I think it's safe to take the error away so your dashboard light goes off.

Thanks for that, racin'skoda! I totally agree, sometimes you just have to keep on. If nobody benefits from my thread right now then it might be somebody later! It's always important to follow up a story and finish it. The times I've had to read a forum post with the exact same problem, only to find the thread suddenly dying out half way... It's the worst! Unfortunately I wasn't very lucky with buying parts because it turned out that the refurbished pump I got from eBay was ALSO faulty. The lesson learnt is that sometimes you can't cut corners and buy used/refurbished parts from shabby places for cheap prices. Because of this I replaced the sensor and this was probably not necessary. In total this set me back an extra £400/500. The car went through the MOT today and the pump works! Finally! Looking forward to drive it. In addition to the pump the garage noticed a wheel bearing had gone as well as a rear suspension spring that had snapped. So I told him he could just replace both, I can't be bothered doing more work on it myself.

Well, actually I'm having some interesting developments the past few days. I had almost given up and sold it, then I suddenly saw somebody selling a "Factory New Pump" on the local Norwegian eBay. I thought I'd give it a try and it looks like it's working! The car is at the garage today getting MOT, fingers crossed. Looks like your pump is dead completely. Try getting it off the car and open it to see the electronics.

Good point, but the new sensor came with new wiring. So the wiring from the pump to the sensor were replaced.

So. I'm still having big, big troubles with my PAS. Problem: No power steering at all. Dashboard warning lights up. Attempts to fix it: - Check fuses - Check negative battery lead - Check alternator wire - Removed spongy wet pump jacket - Install refurbished pump - Install new sensor (metal) We are still getting this error on the VAG: "Implausible signal". Anybody has any idea? According to the Skoda workshop, there is no programming required when installing a new pump in this Fabia I (2003).

And the story continues. We have installed a new (metal) of sensor and I still have the "Implausible Signal" error in VAG. SO ANNOYING! We've replaced the pump (refurbished from eBay) and sensor but the problem persists. We have also checked the alternator lead and although it's tight it's not broken. The negative battery lead is fine too. Sometimes, within a week or so, the battery is suddenly drained. So we thought perhaps we have a current drain. Sometimes we measure 200mAh drain (high!) but other times we measure 20mAh drain (normal). According to an official Skoda workshop, this model pump does not need to be programmed with the car. Can anybody confirm this? At this point I'm lost. Does anybody have any tips?

Are you sure the link is right? It leads back to my own post. How do I program the pump? I have a VAG cable

So, I got the pump (refurbished, from eBay) installed and... Same problem! Wow, this is annoying. Also, the voltage reads 7,7v in the diagnotics. This is strange because before I switched the pump, this voltage seemed normal. Is the sensor broken after all, causing the pump to fail? I'm not getting a read on the sensor, like I used to be able to. The wiring was measured and there was no resistance through them, although that's a rather simple check. Any ideas?

Is it because of water/humidity entering the pump? Do you think it's bad to leave it there or can I just assemble everything after I fixed the electronics? It's quite a lot of work to get it out.

So I have a status update. We have managed to dismantle the pump so we can read the MOSFET identification number! It was a bit of work to get the rotor off but not hard. I think getting the circuit board out is rather impossible, some contacts seem to be spotwelded and the circuit is very integrated. Interestingly, when I googled "buk9508 PHm003" I had only 1 hit. It's from a Romanian VW website about PAS problems with somebody who has the exact same problem. I ended up ordering 5x BUK9508 from eBay for $7,60 there were quite a lot on there. I'll let you guys know when I've replaced the broken mosfet.

You're welcome. The disassembly of the pump from the car is rather easy and straightforward. On my model (LHD) I had to take the bumper off and uninstall the wiper fluid reservoir, but all in all just a few hours work. Then, dismantling the pump might seem a daunting task at first, but if you know what to do you can get to the goods rather quickly. You might think you need to take off the reservoir, but this doesn't help. Also, don't be fooled by the torx screws holding the connectors, because they won't get you inside the pump either. You have to start prying open the silicone seal, then pull off the aluminium cap and voila, there's the electronics.

I'd like to contribute to this thread after having a whole lot of trouble with my PAS lately. The seperate thread is here, but to cut a long story short: One morning, PAS light came on, no PAS. No previous history of PAS problems. Read the OBD with a VAG cable, no signal from sensor, weird low voltages from pump. Checked sensor, seemed fine. Removed the foamy jacket, which was soaking wet. After some weeks, PAS light disappeared, still no PAS. Read the OBD, now voltages were normal and a normal signal from the sensor. Removed the pump from the car, dismantled it and found a blown voltage regulator. Appearantly, water and salt had entered the pump through the silicone seal due to the foamy jacket holding moisture and then destroyed the electronics.

So, this easter I've spent my days in a dark garage while the weather outside was phenomenal. The result: a disection on the pump. The good news is that I found the problem but the less good news is that the money I spent on a remanufactured pump is already spent. After getting the pump off the car, it took some occasional brute force to open the unit. As most of you know and also mentioned in Haynes, this pump is a so called "unservicable" part apart from changing the reservoir. Of course, there's not much stopping 2 curious engineers from looking what's inside. We tore away the silicone seal around the bottom housing, then it slid off and the pumps internals were revealed to us. What you see is three sets of connectors coming into the pump (one set between each torques screw). From right to left: the sensor, the power supply and the communication with the ECU. The big cylinder on the top is the rotor of the brushless electric motor. It didn't take long for us to discover what had gone wrong. On the lefts side, one of the voltage regulators had blown. There was a lot of strange looking deposit on the walls inside the pump. It's either oxidised something (aluminium?) or salt, of which the latter seems more likely since they salt the roads here in Norway extraordinarily much. My theory is simple: A lot of snow, salt and low temperatures attack the pump. The foamy jacket (originally meant for noise isolation) worsens the situation. Moisture (with salt) eventually makes it into the pump. Destroys the electronics (the voltage regulator) and makes the pump seem dead. I remove the foam jacket, the pump starts drying. Part of the electronics springs back to life, the PAS warning light on the dash disappears and the sensor passes its value through the OBD again. But still no power steering due to broken voltage regulator. Such voltage regulators are usually easy to find and from the looks of it, it seems like an easy soldering job. I just have to take the pump a little further apart so I can reach it. Perhaps I could give it a good inside clean while I'm at it.

I have bought a remanufactured pump on eBay and now waiting for it to arrive. Not sure what programming I need to do to get it working but we will see. Any tips on this?

It has the exact same part number so it should do... Perhaps I could get it on a good deal.

I'm pretty sure it's TRW. The product number of the pump/system can be read by diagnostics (see screenshots). No dashboard light! Today I had a weird experience. As it is saturday, I finally had time to look at the car again. So I started it, no steering light. What? I drive it every day to work and back, I've seen the steering light not going out even a second (well, the times when the started motor turns don't count) and now it was suddenly gone! Intermittent power steering Still no power steering when parked, though. So I started driving around a bit and noticed that I got some power steering when I start crawling. I don't think it's 100%, but I can feel something at least. I'm really not sure, I was just really confused. I hooked up the diagnostics again and measured a bit. I get a healthy voltage readout this time (no more low, weird voltages) both with and without the engine running. Also the sensor is now clearly reading a signal, that seems correct! On the other hand, still no power steering when the car is stationairy and the diagnostics also don't show any power (amperage) going to the pump. At least something is happening. Is it perhaps the wet, damp sponge that I removed from the pump and now it finally has had time to dry up? It's started to get dryer, but colder again this week... Fault Codes Ohja, and I'm still getting some fault codes (even though no lights coming on dashboard). First I had: 00566 - Steering Assistance Operation 27-10 - Implausible Signal - Intermittent Then after clearing it I got: 00566 - Steering Assistance Operation 27-00 - Implausible Signal Diagnostics Here's some screenshots of the group diagnostics: Doing a short drive through the public garage: Turning all things (heated seats, wipers, window heating, high beam, electric windows) on, then off again to see how they affect the voltage.

On my sensor, it was on the side. It was not easy to see, since it was molten/carved in. See my photos.

Thanks for the feedback fabdavrav! Is this the new improved type? I suppse not, since I don't see any goldy coloured cap, but it is metal though.

That's interesting you're saying that because I'm having problems with my PAS while I'm having damp footwells too! I've described my problem here, in a seperate topic. I'm also having battery problems. I replaced the battery since I thought it was bad, but I have a feeling that the new battery isn't holding up too well either. My PAS problem is not intermittent though and I have no dimming lights issue either as far as I know. Also, I already have the rear door repair applied, thought something is still getting wet there since the panel was moist when it rained a lot. I have really no clue what's going on here...

Thanks a lot for the detailed reply again Avalon, it's well appreciated! I agree with what you say. I should have measured voltage at the pump yesterday! I've put it back together again since I don't have a dedicated garage. Taking it all off again is a hell of a job, I tell you. Not difficult but just the amount of hours that goes into it. I've looked on eBay.co.uk a little bit and they are indeed really expensive! http://www.ebay.de/s...os&_stpos&gbr=1http://www.ebay.de/s...os&_stpos&gbr=1 are even more expensive. The cheapest used units I could find go for about £100 + shipping and in my case you can add 25% tax to that. I'm lucky if I can find this part in Norway for cheaper. Anybody an idea about the compatibility? I'm pretty sure I have a TRW, but that's about all I know. I couldn't see any official VAG part number on it, only a bar code with a weird number that doesn't give any hits on Google. Anyway, if it's not the power, it's either the pump or the sensor. How do I find out which one it is? I suppose that when the pump is dead, the sensor won't read a signal either since it goes through the pumps ECU. But in case the sensor is broken, the pump won't do anything either. So I'm having a hard timing choosing which (expensive) component I shall replace first.

So, I've been lying under the car again, no luck. I checked fuses, battery leads, the pump itself and the steering angle sensor. I'm not sure how to measure whether the pump/sensor are dead. How do I do that? Anybody has an idea what's wrong here? I still find it strange that the diagnostic measured less than 12v at the pump... Fuses I took some fuses out, they looked perfectly fine to me. Didn't replace them (since I didn't have any spare) but I can't see how this can be the problem. Here is a picture of it. Battery The battery seemed in great condition. But just after christmas, when the car had been standing still for some days, it ran out of juice as I was trying to start. It was way too low on capacity. So I bought a new one and mounted it. It starts like normal again but it didn't solve any problems regarding the PAS (I even cleared the diagnostic errors). Negative Battery Lead Seems fine, but should perhaps replace it to be sure? I live in Norway and it's not easy to get parts. Steering angle sensor Man, can I just start off saying that this thing is quite hard to get to?! So when I finally got it out it seemed fine, no traces of water or something. it's the G250 TRW with fixed cable and it's part number is 6Q1423291. It's plastic and not aluminium, so does this mean that I have the notorious plastic one? I read here that it is a common failure, but it didn't seem to have water in it. Pump This was quite a job to get to. The RHD version has the wiper liquid reservoir around the pump, so this has to come off together with the bumper, battery and air filter. The plastic around the pump was completely nackered, very very brittle. The sponge around the pump was totally soaked. I left both off. Perhaps this caused a short and killed the pump?

Thanks Avalon for your input. I did actually check the fluid level of the PAS the day after it stopped working, I forgot to mention that in the startpost. The level was below the minimum. When I'd put in the dipstick, the dipstick would JUST reach the oil level and get a little wet, but it was under the minimum. So I topped up, but no change. The fault codes by Ross-Tech: 01288 - Terminal 30; Steering Assist: Signal too Low 00566 - Steering Assistance Operation: Implausible Signal The combination of these 2 together makes me think it's a connector/fuse problem and not necessarily a broken pump unit, what do you guys think? Similar problems/topics: Power steering Failure - Can I still drive it? VAG COM Scan Results I have the following action plan: Check Fuses I'm aware of the possible hairline crack. I'm planning to take out the fuse and have a look at it. I'll buy a new one after the holidays. Check Battery The battery seems in great condition. The indicator (green) says its healthy. I have a newer, 47Ah battery lying around. I know this is too small of a battery but I might give that a try just to see. Check PAS fluid level Was low, but topping it up didn't solve the problem. Do a diagnostic check Results in the start post. Check/Replace Negative Battery Lead Check the steering angle sensor Check the the alternator wiring (ref.)

So it's been a few weeks now without power steering. I've tried several simple things but I've come to the point where I need some help. Any advice is welcome. Skoda Fabia 2001 1.4L (AQW) with 125.000 km on the clock. After a few cold weeks here in Norway (down to -13 degrees C) I started the car in the morning and the PAS light came on. No functional power steering. I tried turning the car off and on, same problem. No history of PAS problems with this car known. Tried to look at the fuse box, no visibly broken fuses. One strange thing, according to this online manual, terminal 5 is supposed to be the PAS (50A) but that terminal is empty in my car. I have a red/green wire on a 40A fuse on terminal 6, so I suppose this is the PAS. Ordered a VAGCOM cable. Tried the cable and got the following information Before ignition Fault Codes 01288 - Terminal 30; Steering Assist 07-10 - Signal too Low - Intermittent Before ignition Measuring Blocks After ignition Fault Codes 00566 - Steering Assistance Operation 27-00 - Implausible Signal 01288 - Shareware Version. To Decode all DTCs 07-00 - Please Register/Activate After Ignition Measuring Blocks Interestingly, the voltage on the terminals is lower when the car is running. Not sure what the normal voltages are for these terminals (12v I suppose?) but I'm not even sure where I can find these in the car. Any ideas of whats wrong here?

I must thank you, because you were right. I have a leak at the wheel cylinder back... Saves me stressing about changing the master cylinder and servo. This doesn't explain the small leak of some sort of fluid from the pedal box though, but this worries me much less at the moment.

I've now also attached the photo so you can see the 'leakage'. I've never looked down there before so I don't know since when it's there. But it doesn't smell and it feels much like brake fluid but I'm not sure. I will see if I can unmount the back wheels to check the wheel cylinder. This should be visible after disassembling the wheel and then the cylinder, right?