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46

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 29 October 2023, 20:58:45 »

For the earlier Carlton/Senators, it looks like the 'current' part numbers are...

VX-90510208, OP-5-30-409, BOSCH 0265001220.

Given that the hubs and knuckles are the same on Omega B, I suspect these will fit and work just fine. Might be worth a google to see if you can get these.

Interestingly, on Rock Auto the seem to list 4 or 5 aftermarket sensors for the 2001 Cadilac Catera. The pictures show these as having plastic bodies. I wonder if these are less prone to "rusting in"

47

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 29 October 2023, 20:15:30 »

Buying second hand ,genuine knuckles with genuine ABS sensors would be a way back to working ABS
not cheap though as you'd have to fit them, then get an alignment 

what happened to the original sensors 

I purchased low mile Omega B2 hubs/sensors  as spares when i had omega As (Vauxhall Carltons) years ago 

Yep! New sensors will be ordered. But I think I use the old knuckles, and use some material inbetween to increase the distance if needed.

I don't mind the fitting, as I do all the work on my car myself in my garage. Since I've replaced suspension I'll need an alignment regardless. So that's OK!

The original sensors broke as I tried removing them, while replacing suspension parts. The Haynes book stated to do so, but it would not have been necessary. All of the problems I have with the ABS is just an unlucky side effect from wanting to replace suspension parts.

If you do buy second hand knuckles, think long and hard before you attempt to remove the sensors from them. I have never, repeat NEVER, in about 10 attempts, managed to get one out in one piece. They are always 'welded' in. I suspect its dissimilar metal corrosion - the hub is cast iron, and the shell of the sensor is aluminium. Once water (and salt in the UK) get at it you're stuffed - the things will not come out in one piece if they've been in more than 5 minuites.

48

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 29 October 2023, 14:46:31 »

Didn't get as far as I'd hoped today - took ages to find the old bits, and they needed quite a lot of cleaning. However, results so far...

https://ibb.co/Lkz0pzF
The Hubs are made by KOYO - both the bearings and the cast wheel flange are marked as such.

The ABS reluctor ring has 48 teeth, with an inner diameter of (about) 75mm and an outer diameter of 95mm. Each tooth is 2.5mm wide, and 2.5mm deep.

https://ibb.co/JdBJ3KT
The ABS sensors carry several markings on the wiring side, but these just look like date codes to me. I'll put it under the microscope at work (tomorrow) to see if I can get anything off it.

The sensor tip side looks like this...
https://ibb.co/VvTLPn7

The 'blade' of the sensor is 2mm wide, and 9mm long. It stands 5mm proud of the steering knuckle. The blade is aligned to point towards the hub axle axis. The body/barrel of the sensor is (about) 17mm diameter, and stands about 1.5mm proud of the steering knuckle.

The next step is to assemble the bearing onto the steering knuckle and measure the clearance from the tip of the sensor to the reuctor ring. Unfortunatley I can't do that at home - the surface rust on the knuckle doesn't let the bearing slide on, and I don't have the tools here to 'force it on'. So tomorrow I'll polish up the knuckle/bearing surface and measure it, and then take some 'scope readings of the signal generated by the sensor at various RPM's.

49

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 28 October 2023, 18:13:46 »

Perhaps you are over thinkng the whole thing.

Given that the system doesn't work correctly with those sensors and that the sensors don't fit correctly, the simple fact is that you need the correct sensors. And possibly bearing assemblies. (Omega A and Omega B hubs may seem to be similar, but that doesn't guarantee that they are the same and it would be all too easy for the parts suppliers to make the same assumption).

Anything else is a waste of time and effort unless you're retired and extremely bored.

Trying to position the wrong sensors in the correct position is akin to trying to make a rear door fit the front door aperture... You might make it latch, but it will never function correctly.

I've never looked at the electronics inside an ABS control unit. If I had to guess I'd say the differential input goes into a balanced op amp which converts the sine wave to a digital input. But that's a guess.

The issue with reluctance sensors is that their voltage output is very frequency dependent. Given that the system is supposed to work from 5MPH to 150MPH there will be a very large variation in the signal amplitude at these two extremes - small at low speeds, very large (as in hundreds of volts) at high speed. I'll try and set it up in a bench drill to measure/demonstrate tomorrow.

But the point is the system will be setup to work reliably from 5mph to 150mph with standard clearances. If you move the sensor too close, it may overload the system at higher speeds - I know this is an issue with the Lotus Carlton ignition sensor, which is also a variable reluctance sensor. If the gap is too small, the ignition module misfires at high RPM due to being overloaded.  The cure is to put in shims to space the sensor away from the timing wheel - there is a field service note in the dealer manual to do with this. It's unlikely to cause damage inside the control unit, but it can cause mis-triggers. The LC timing sensor spacing is specced at 1.5mm gap. The ABS sensors are similar, and 0.2-0.3mm clearance doesn't sound right to me.

50

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 28 October 2023, 14:02:52 »

Both the frequency AND amplitude of the sensor output will increase with RPM. You say you are measuring at 2 RPM. Assuming you're using 235R45x17 tyres, the rolling circumference is 79.57 inches (2021mm). 2 RPM is 120 revs per hour, which is therefore 9548 inches per hour, which is only 0.15 miles per hour.

I don't think the ABS is supposed to work at all below 5mph. Therefore the voltages you are seeing from the sensors are not representative of what you should see if the car is travelling at > 5MPH (8 Km/h).

Your 50mV at 2RPM might be correct - Try it again at a more realistic 200RPM (15 MPH), you should get a much larger signal - probably 20-50 times larger. Remember the ABS needs to work all the way up to above top speed (say 2000RPM/150MPH) so the signal can be massive at that speed. If you adjusts the sensors to give large signals at very low speeds, then at normal/high speed you can overload the ABS inputs.

I've got some old Carlton hubs in the lockup, still with the ABS sensors fitted. I'll dig them out tomorrow and measure them up for clearance. 0.2-0.3mm sounds way too close to me.

51

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 27 October 2023, 22:59:54 »

Sounds to me like the wrong sensors. EPC doesn't show the OEM part number, but most braking stuff on large Vauxhall/Opels is Bosch. Certainly is Bosch on Carlton/Senator.

I've never heard of Holstein (except as a cheap Beer here in the UK, and as a state in Germany)

52

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 27 October 2023, 18:13:51 »

I've only played with Carlton/Senator ABS, not Omega B, and it might be different - but.....

There is no ground on the sensors. The two sensor wires are differential all the way to the control unit. Infact the resistance to ground of both terminals is many hundreds of K-ohms. If either terminal is somehow shorted to ground, the ABS fault light comes on.

As I say - on the Carlton/Senator.

Thank you! That is valuable information.

I have measured the resistance of the terminals to 6.8M Ohm on both sides, and I assume that reading is OK.

Yes, that sounds about right.

The sensors are called variable reluctance sensor. Their output signal amplitude is a function of both RPM and clearance. You seem to be saying that by rotating the sensor things get better/worse. Note that the clearance is important - if the sensor is too close to the reluctor ring then it'll generate too high voltage, and this can upset the control unit. Rotating the sensor will reduce the amplitude as the 'blade' of the sensor becomes mis-aligned with the teeth on the reluctor ring..

So check the clearance between the tip of the sensor and the reluctor ring on the wheel bearing. I don't know what it is supposed to be, but I'd expect something like 1mm-2mm. You say up thread that it is (almost?) touching. That isn't correct. If it is, then the sensors are wrong but you might be able to correct it by putting shims in between the sensor and the steering knuckle.

53

Omega General Help / Re: ABS-light constantly on after replacing front ABS/wheel speed sensors

« on: 26 October 2023, 23:00:47 »

I've only played with Carlton/Senator ABS, not Omega B, and it might be different - but.....

There is no ground on the sensors. The two sensor wires are differential all the way to the control unit. Infact the resistance to ground of both terminals is many hundreds of K-ohms. If either terminal is somehow shorted to ground, the ABS fault light comes on.

As I say - on the Carlton/Senator.

54

General Discussion Area / Re: Stemoshire.

« on: 22 October 2023, 22:50:02 »

It seems things can escape from beyond the event horizon that is Barnsley, My parcel is now marked as delivered, on Saturday at 11:54AM, to a buisness address that will have been unmanned at the time. I wonder what state the thing will be in though.

55

General Discussion Area / Re: VOIP suggestions

« on: 20 October 2023, 16:16:41 »

my landline and my mum's works without power in the house (depends on the type of phone you have )

Yes, analogue land lines work because they are powered by DC coming down the copper phone lines from the exchange. So providing the exchange has power, existing analogue phones still work if you have a local power cut.

if BT have a power cut ,it's unlikely to be on  the same grid 

What BT are doing down our way is putting electronics at the top of all the telephone poles ready to force us all onto VoIP. I asked the engineers about it whilst they were doing it - they said it's powered off the local 240V grid. If the local 240V grid goes down (aka a power cut) then the electronics at the top of the pole will stop working, and we'll lose our phones even if we have home battery backup. Nothing to do with the exchange having power or not.

GSM based devices (with a sim card)  are also available ,

Yes, but they aren't being given out by the elderly home care companies (yet).

56

General Discussion Area / Re: What has P*ssed you off today?

« on: 20 October 2023, 14:59:02 »

Hermes.

Been waiting from a couple of seals from Rock Auto since October 10th. Chose DHL for delivery option. Once in the UK, DHL have given the package to Hermes, who tried to deliver it on Oct 18th, to a Buisness address, at 06:08PM. Of course there is no-one here at that time, and despite it only being 0.098lbs, did they put it through the letter box. Did they bollaux. So it goes back to the Avonmouth depot. Left Avonmouth on 19th heading to ... Barnsley, where it arrived at 11:53. Latest tracking shows it is now at the Barnsley Delivery terminal at 12am on October 20th.

The effin thing is getting further away!

57

General Discussion Area / Re: VOIP suggestions

« on: 20 October 2023, 12:49:00 »

Contract free ,set the numbers it calls ,and has back up batteries .
Clicky  SureSafe Personal Alarm
plenty of similar devices about too
Panic Distress Intruder Alarm cheapo    
obviously ,the new-fangled router thingy will need UPS

Neither of which will work during a power cut. Doesn't matter if these devices have battery backup - the BT side of things does not.

58

General Discussion Area / Re: VOIP suggestions

« on: 20 October 2023, 11:41:18 »

BT will move you to a VOIP

Does this mean new equipment like phones and incoming sockets etc  the reason I ask is that I was thinking of having mine moved and with VOIP bering talked about then maybe wangle something on the cheap

No, basically a new broadband hub / router that your phone plugs into.  phone network becomes a pure data network at the exchange level so phones will no longer work in an ordinary socket.  nothing to do with fibre, thats just a better way of getting that data network to your house.

And nor will they work during a power cut. Work of the devil if you ask me.

Indeed, thats causing a bit of a stir, are some backup battery options apparently

My mum had, and my nextdoor neighbour has, one of those local govt supplied 'panic' alarms - which are basically big red buttons that they hang round their necks and press if they have a fall or somehow become immobilised and need help. These won't work in a power cut. AIUI even if you've got local battery backup they still won't work, because the electronics in the BT cabinates relies on grid power. Your end might be Ok, but their end will be down. 

59

General Discussion Area / Re: VOIP suggestions

« on: 20 October 2023, 10:03:07 »

BT will move you to a VOIP

Does this mean new equipment like phones and incoming sockets etc  the reason I ask is that I was thinking of having mine moved and with VOIP bering talked about then maybe wangle something on the cheap

No, basically a new broadband hub / router that your phone plugs into.  phone network becomes a pure data network at the exchange level so phones will no longer work in an ordinary socket.  nothing to do with fibre, thats just a better way of getting that data network to your house.

And nor will they work during a power cut. Work of the devil if you ask me.

60

Omega Electrical and Audio Help / Re: Internal lights & seat adjustment not working.

« on: 19 October 2023, 14:43:26 »

Thing is, fuses usually go pop for a reason, particularly ones that are 20 years old. If it goes again in the near future then you probably do have some other problem.