ABS Wave Forms

[hefaus]

Hi. I would like to know if anyone has and could post a wave form that is good versus a bad on a two wire abs sensor and a three wire as well for comparison on each type. Thanks in advance.

[Joe Rappa]

This is an old Modis file, and not a common failure. This is not a bad WSS, but a dented tone ring. A much more typical failure would be to see one WSS with a much lower amplitude.

[hefaus]

ABS Wave Forms

Thanks for that one Joe. I hope I get some more samples yet

[hefaus]

Wss

Hi. Anybody have any Wheel Speed Sensor Waveforms that they can share?

[David Green]

I guess I will have to try the VP again using a higher voltage and sweep rate setting?

The example shown is saying a 50V and 200ms sweep rate?

I used a 20V scale and possibly the graphing meter, which I now think produced the wrong type of signal?

Looking at the 2 channel lab scope I can see that from your example I am able to adjust the voltage to 50V and the same sweep rate of 200ms. The scope indicates that the settings are 10V/div AC, the trace is either starting its slope upwards or downwards depending upon how I set it up initially, but along the lower screen to the left the display advises that the settings are DC, yet the scope display advises AC per trigger?

The other point I can now see is that the waiting for trigger points are both starting at the same position on the scope, i.e. 0, so if two channels are triggered then would these overlap each other?

It is interesting how snap on say that the instructions for this VP are built in, thus no manuals or DVD's to help use it, yet all the information in it is either incomplete, or is related to how to test sensors and actuators, but no user manual on how to actually set up and use the VP

David

[Joe Rappa]

You probably won't need a voltage range as high as that. That car was rolling pretty good when that snapshot was taken. The voltage really climbs as wheel speed increases.

Joe

[greasybob]

This is the only ABS signal I got stored. Most of the ABS problems I get can be solved by using the scanner graphs, either signals that drop out or just are not there at all due to bad sensors or corroded wires. This is a tow wire signal from the front of a Ford F350. On this vehicle the signal was good, the problem was in the ABS module, it got lost in there, dropped of the scanner data.

[greasybob]

SORRY, that was "two wire sensor" not tow wire

[David Green]

I have had a previous signal like that on my VP from my Audi, but I put it down to incorrect testing/signal set up because the manufacturer instructions advise that the type of signals to be recieved are analogue, i.e. like the examples in Joe's above. But I am not saying the signal is wrong for your vehicle, just that in my experience it is possible to set up the VP wrong and gain the wrong type of signal.

David

[JR-1]

Hi Dave , like you i just purchased a vp and finding my way .Tech topics will be bringing a hand book out soon for the vp . Getting good known scope traces will take time but with the help of these guys on here then we should get there ok

Regards all and happy Easter ()

[hefaus]

This is the only ABS signal I got stored. Most of the ABS problems I get can be solved by using the scanner graphs, either signals that drop out or just are not there at all due to bad sensors or corroded wires. This is a tow wire signal from the front of a Ford F350. On this vehicle the signal was good, the problem was in the ABS module, it got lost in there, dropped of the scanner data.

Thanks for the pic

[David Green]

ABS Rear Wheel Speed Sensors outputs

Hi JR-1

Welcome to the forum. I have been playing again this afternoon with the VP, yep its definately a learning curve for me . I took the VP on the road again today and up and down the East Lancs, I am pritty sure JR-1 you know the road I mean , however no matter how long I would drive up and down that road my ABS would not falter at all , I was beginning to think that maybe it was just a bad wiring connection at the ECM

So I made my way to the M61 motorway, this time after a while the ABS came on, but I didn't quite get to Scotland before it did

I will post a picture 'one of' what I recorded on the VP, however it's a BMP which I knew about but did not think about when recording . The VP also recorded two movies in 'LSP', but when I try to open them with SSC I get an error message which prevents me doing so, but I can observe them on the VP as live data either manual or auotmatic

The glitch point;

This I am still unsure as to whether the VP is able to see these types of faults, as I was driving along the motorway I kept my finger on the trigger to capture and save the data as it happens, but looking back through the scope traces live and in manual mode it is difficult to establish which trace is actually indicating a fault?

The trace loaded here is longer than shown, but on here I am uncertain if the fault can been seen, but I am learning all the time .

David

[hefaus]

Solus Pro

Hi JR-1

Welcome to the forum. I have been playing again this afternoon with the VP, yep its definitely a learning curve for me . I took the VP on the road again today and up and down the East Lancs, I am pritty sure JR-1 you know the road I mean , however no matter how long I would drive up and down that road my ABS would not falter at all , I was beginning to think that maybe it was just a bad wiring connection at the ECM

So I made my way to the M61 motorway, this time after a while the ABS came on, but I didn't quite get to Scotland before it did

I will post a picture 'one of' what I recorded on the VP, however it's a BMP which I knew about but did not think about when recording . The VP also recorded two movies in 'LSP', but when I try to open them with SSC I get an error message which prevents me doing so, but I can observe them on the VP as live data either manual or automatic

The glitch point;

This I am still unsure as to whether the VP is able to see these types of faults, as I was driving along the motorway I kept my finger on the trigger to capture and save the data as it happens, but looking back through the scope traces live and in manual mode it is difficult to establish which trace is actually indicating a fault?

The trace loaded here is longer than shown, but on here I am uncertain if the fault can been seen, but I am learning all the time .

David

Hi David.Have you tried capturing with your Solus Pro? Seems there should be something showing when your vehicle acts up. Give a try and post. Have fun.

[David Green]

The solus pro will not record over I think 12 - 14 Kmh which means that I get a rise time and then a straight line, the data from the back door of the solus pro for ABS diagnosis is not really that good.

I was really hoping that the VP with the use of the scope and recording facility would be better, but I think the main part of the VP missing is that it has no 'Contineous record facilty' like the SP has, which for those diagnosis parts which need to be on the open road to capture, its a shame

May be SO will consider a software change at a new update so that these types of faults can be recorded on the open road with safety in mind

David

[JR-1]

Hi Dave , how long does the vp record for ? , have only tried it for about 10 mins .I'm pretty confident it will pick up clitches ok .As for you scope trace , try again to send the scope movie .I haven't had any bother with that .I just save the file ,pop it on shop stream then name it to what i want and have a nice look

Have some nice scope movies at work to look at

Regards
John