Graham Butcher

Oh, thats useful information, thanks for the link 👍

To an extent it is to me and electronics is my hobby, I love to repair audio equipment and also test gear, but I have to confess that modern digital electronics leave me a little confused.😁

No, they take the incoming 12V supply and then via the internal chips superimpose a square wave signal whose frequency is dependent on the wheel speed, whereas the ones with a coil and a magnetic core are passive devices that actually do produce a weak AC voltage which is a sine wave and does not require a 12v supply, unlike active sensors.

I just had a scan through my online manual and here in lies the answer, these sensors are indeed active ones, even though they only have 2 connections, so that means that the ABS controller itself forms the load effect for them to operate?

I no longer have access to a sensor without ripping my wheel off again, and I'm not planning on that again anytime soon, I'm not as agile as I was once. Years ago popping wheels of a double-decker bus posed no problem for me, that was where I did my apprenticeship, with what was then the National Bus Company, as an Auto Electrical Engineer. Now 73 and way out of condition and to big for this game.

Thanks for the info, where did you get the wiring diagram from?

Yeah I thought there might be a diode, but what would be the purpose of that if there is just a coil and magnetic core within it. I'm not going to be replacing it, if it does get replaced, it will be the garage doing it, so I'll try to remember to ask them for the old sensor back in order to try and dissect it, if they do replace it. I'm intrigued to learn its secrets as well. Where are you reading the circuit diagram from? I have downloaded one, but I don't recall seeing the ABS system in it.

Yeah, I don't know if the first Superb is the same or not or indeed what other cars run with. This is the first time I have had to physically interact with a car for over 40 years as I have always had company cars in the past. Infact my current car was my company car which I purchased when I retired 6 years ago. So this is a steep learning curve for me.

Not when you have small croc clips that are directly onto the 2 flat pins which protrude from the sensor and then to prevent accidentally disconnecting a connection in the small sensor housing, you unplug the banana plugs from the meter and reverse them. The lead which plugs into the sensor has 2 recessed sockets that the 2 flat pins enter to make contact. Using the meter probe leads instead of the croc clips, reveals that there is no power to the sensor until the engine is actually running.

That is exactly what I thought and all the examples I could find on YouTube also stated that, but there are indeed some new sensors on the market that are 2 cores only, and so they must rely on the ABS control unit to act as their load.

That is precisely what I thought the sensor consisted of, but no, there is electronics inside them for sure, they are 100% polarised and the positive and negative of the supply must go to their dedicated pins on the actual sensor. I tested the sensor using my Fluke 85 DMM and the resistance specification of that meter is upto 40Mohm and the sensor when connected one way round (and they are only 2 pin sensors) gives a reading of O/L (in excess of 40Mohm) and when the connections are reversed, reads 7.5Mohm. A straight forward coil is not polarity minded.

Thanks for the feedback on this issue, here is the current status of the problem. I have cleared the error codes 3 or 4 times now and the problem goes away. It can be clear of errors for weeks at a time and then suddenly it will strike again. Clear the errors, and it can then either come right back on again, or it might be clear for a few miles / days before coming back again. It is always the same codes each time, and it always mentions the rear N/S wheel sensor and each time I have switched over to live data and driven for while observing the live feedback from all 4 wheel sensors, which always comes back with all 4 sensors reading the same values. I Googled the results about the N/S rear wheel sensor, and it came with many YT videos on the problem, suggesting that I should use a multimeter to check the resistance of the sensor and the general view was that a value of several Meg ohms was not acceptable. One video suggested it should be around 50K ohms, and a manufacturer of ABS systems, own channel, said that the average reading should be around the 1K ohm, I was reading 7.5M ohms on the one fitted. I went and purchased from GSF motor spares, one of their Premium range sensors at a cost of £39.90 after their Easter discount and before I set about replacing it, I measured its resistance, and it came in at 3.5M ohms, and I thought WTF, this looks faulty going by the YT videos were suggesting. After looking into it in a bit more depth and asking on an electronics forum, it seemed that the sensors are Hall Effect sensors and that these could have various resistance values as they contain microchips inside the sensor body itself and that these chips, given the current global shortage of microchips, might have slightly different chips fitted and hence the different resistances, but still function OK. The car has been bottomed on a couple of occasions while been driven slowly over rough ground, so it may have damaged the cabling under the body, the cabling in the wheel arch is fine. Couple this with the fact the live sensor readings has made me come to the decision that the problem might well be under the car and that I cannot access it any more because of my age, without a pit or a lift, so I have booked the car for a full diagnostics check with VW group specialists using the same software as the factory, to investigate and cure the problem. I have reservations about it being on the wheel at all, be it the sensor or the reluctance ring on the hub, for the reason that if the ring had damage then it would be showing up when doing live data readings, and with the vast amount of potholes on our roads, especially in Essex, constantly jolting the car, some which really make the car shudder with the impact, could be making any damaged cabling make intermittent connection problems and setting alarms off again. So I have returned the purchased sensor for a refund, as I might have ended up fitting it, and still having the problem, then replacing the reluctance ring and still having the same issues, all the time building up the cost, and still having to resort to the garage who has the equipment to resolve it for me at extra cost. Had the live data tests shown up an issue coming from the N/S rear wheel, then I would have replaced the sensor with the new one. But without being to pinpoint that the issues was indeed at the wheel, I might just have been building up the costs unnecessarily, which is something I need to avoid being a pensioner. I think you all for your inputs, when the garage has concluded, I'll let you all know the outcome, but won't be until next month now when they get around to looking at it for me.

Well, after reading these reports, I decided before going ahead and fitting the new sensor I purchased that I'd do some live data testing with my OBDII device plugged in. Drove it around the town a couple of times and the data never missed a beat, all 4 wheel sensors gave perfect results, so that to my mind should really confirm that both the sensor and the hub ring must be OK and the message I'm getting from the device is a generic one. I have saved screen prints of the fault codes which I have the following: 18255 Please check DTC memory of brake system ECU 0047 TV-Tuner (R78) 13637396 Manufacturer-specific code (tap to search) 13705985 Databus - Received error message 01316 ABS Control Module 02214 Tyre pressure warning 00290 Left Rear Wheel speed sensor (G46) So armed with this data, is it best to book it in and let the garage run through and cure the problem?

Arh, this looks interesting, just where will I find this connector, under the bonnet or what?

No, because I have difficulty getting up and down (too big and old for that malarkey) and the units are so hard for me to get access to without either a pit or a lift to give me easier and direct access.

Thank you for these measurements, even taking the findings of the person in the video where he measured 50,000 ohms, that makes this new one I just purchased from a motor factors, 70 times that value and taking your value of 1.1k for a new Octy sensor, it makes my new one 3,182 times higher. I really can't see that there would be any reason for one to a fit a Superb should be any different, so I'm feeling pretty pleased that I didn't fit this one as it rather looks like it's duff already 😲

Thanks for the reply, how many miles had yours done at that point and was there much rust around the wheel area? Mine has zero visible rust anywhere that I can detect so far, and all the hub ring videos I have seen appear to be very badly rusted.

I have just got this problem with mine and posted on here about it. My local dealer cannot get round to it for 3 weeks, so I have been searching for info myself on how to cure the problem. I found a video (below) on Octy, so I checked the resistance on mine, and it was 7.5Mohm and his faulty one was 9Mohm and his new one was 50Kohm. So I have been out today and purchased a good one from a decent brand (Hella) but checking the resistance it measures 3.5Mohm, so not fitted it yet in case it's faulty as well 😨. Checked a few YT videos and some people say refer to the workshop manual for values, I cannot find any mention of the resistance in the manual, so I'm still not sure.

I have had a few issues with the dash warning lights coming on with warnings for Power Steering, TCS, ESC, ABS, Bulb failure and Tyre Pressure all at the same time. Plugging in my OBDII device it checks for error codes and one code that is not an actual number is for the left-hand rear wheel sensor which is the ABS sensor. I switched over onto live data setting on the OBDII and selected ABS sensors mode and drove for a short while and observed the readings, all 4 wheels were turning at the same speed? So I cleared out the codes and all seemed OK for a few weeks and then the same thing again happened, cleared the codes, all OK Next I searched the web looking for clues and I came across this video of a person having similar problems with his Octavia so I pulled my N/S rear sensor and checked its resistance value and it 7.5Mohms and in the video he says the resistance of his faulty one was 10Mohms and his new replacement was 50Kohms. So based on that I went and brought a new sensor made by Hella, not a China knock off, and before fitting I measured the resistance, and it reads 3.5Mohms. So I have not yet fitted it as I don't want to fit it in case it is faulty, so does anyone actually know what the correct value should be? I have been through the downloadable purchased workshop manual, and it does not give that information.

No, according to my dealership, petrol cars are not being sold as much as diesels. I expect that is because diesel is more expensive at the pumps, even though you get better MPG with diesel. I have heard similar stories from other people as well. Road tax on a diesel tends to be more expensive because of the higher emissions, that could also be a contributory factor. Whatever, I, for one, won't be selling my diesel anytime soon, that's for sure.

I can join you there, I'm 6ft 4" and so are my 3 sons and with my seat in position they can just about still sit behind me. I have heated seats all round and in the rear there are also removable footrests like there are in a Rolls-Royce as well as the door mounted umbrellas. The BMW 5 Series is supposed to be from a higher level car range, but like so many cars in that arena, its more about paying for the badge. A while ago, while waiting for my car to be manufactured, I was given a hire car for a couple of months, Mercedes C class, it was really awful, once you got over the excitement of sitting behind that 3 - pointed star, you begin to notice the annoying things and the other small shortcomings, especially the lack of interior space. There is no mistake, space is a luxury. My car was at the dealers recently having a now radiator fitted and the driver who picked me up when the car was ready was telling me that he was selling his wife's Hybrid car and buying a 2nd hand diesel Octavia as people are panic selling their diesels and buying EV's following the governments announcements to ban sales of new ICE cars in 2030. This translates into excellent prices to be had on 2nd hand diesel cars at the moment. I plane to run mine for as long as possible, I relish the idea of shelling out thousands for new battery packs, or having to keep stopping to recharge. One thing you can be sure about is that when transition to EV is complete, electric prices will escalate like a skyrocket, plus when we all need the electric to be there, it won’t, there will be all kinds of outages due to storms, equipment failures or industrial action etc.

Oh, that's not so good. My car has only had me as its driver from new, it was my company car and had no issues with it at all until I retired and purchased it from the leasing company. Within a couple of months of buying it, I got sideswiped by a foreign truck on the M25. Had it repaired, then a year later, someone ran into the rear ☹️. Got it repaired then a few months later the alternator belt snapped on me. Overall though, the car is excellent, its never been thrashed in any gear, never been driven hard so it made perfect sense to buy it, I know the cars entire history. So far it has flown through every MOT without any problems.

I'm not so sure that it is the engine struggling, but more a case of the low RPM exposing more of the pure grunt of the diesel engine (assuming yours is diesel as well?) I always try and ensure that my RPM's are around the 1500 to 2000RPM max, so I'm not expecting any issues with the dual mass flywheel as I believe that the dual mass comes into effect at higher RPM's in much the same as the weights on the distributor of an old pre injection petrol engine come into effect at higher engine speed to advance the ignition timing. What is your mileage, as I've heard it said that the flywheel is not normally an issue until well over the 100,000 miles. My mileage is 70,050 and is an 8-year-old car now and still drives as if it is a new car.

I think you will find that the precise time when the DSG shifts will vary according to eng and also the gearbox oil temps, how heavily the engine is loaded and the throttle position etc. I notice that when the temps are low, the changes occur later as the oil imposes a load on the transmission. When the oils are at normal temp, and I'm on flat piece of road and only light throttle applied, that mine will often slip into 4th at around 1200 RPM (24/25mph) and into 5th at around the 30MPH mark and pulls happily. Apply any more throttle or a slight incline and it drops a gear.

I have been having to top up the coolant level every 2 weeks or so for the last 4 to 5 weeks, about a quart has been added each time and after a couple of weeks delay, my dealer has been able to have a look at it and has said that the radiator is leaking and needs a new one at a cost of around £450 which I assume is the fitted cost. It seems a bit expensive to me, but is it really? I don't actually know what is involved in replacing the rad on this car. Many years ago when cars were so much simpler to work on, I used to do all my own maintenance and whipping a rad out and getting it re-cored the same day was not an issue. There used to be loads of companies doing rad repairs but I have not seen one in years now.