connecting to an abs sensor

[jonnyboy]

Hi....Im a new user of the vantage pro and of an oscilloscope in general. I am trying to connect the vantage up to rear ABS sensor of a peugeot 307 but seem to be having a few problems. Basically as a new user im not completely sure how to connect to vantage. The on screen instructions say to connect yellow to wss+ and black to wss-. So is that just connecting across the two wires of the sensor?Now do i leave the harness connected or seperate it? Also ive read other info saying you can connect to the signal wire and to a ground on the vehicle? Im just not getting any pattern at all so i guess im doing something wrong.

Any help appreciated.

Thanks....Jon.

[Steve6911]

WSS+ and WSS- is telling you to test across the sensor. If you use backprobe pins you can leave the harness connected, if you dont have them you can't. You need to spin the wheel as fas as possible to get a pattern, then connect to another WSS on the vehicle and compare the two.

Steve

[jonnyboy]

Thanks for the quick reply......have tested as you said but seem to get no pattern even when testing another sensor......is it possible i will only get a signal when the car is driven?


Jon.

[Steve6911]

Are you backprobing or have the harness seperated? If your not getting a signal on a good sensor as well I would think that your not making contact.

[jonnyboy]

I am backprobing.....i did think of a bad connection so i disconnected the harness but still had the same problem whichever sensor i was testing. As it happens i read on another forum about particular problems on the peugeot 307 with regards to sensor gap. So i checked the gap on the o/s/r sensor which was flagging up a fault code and it did seem quite a large gap. I reduced the gap and it has solved the problem with regards to the ABS fault. I cleared all fault codes, test drove the vehicle and all is well. When i connected the vantage back up to the sensor after reducing the gap i did get somewhat of a signal but absolutley nothing like the reference waveform. Is it possible that different vehicles will produce completely different waveforms?


Jon.

[Crusty]

I am backprobing.....i did think of a bad connection so i disconnected the harness but still had the same problem whichever sensor i was testing. As it happens i read on another forum about particular problems on the peugeot 307 with regards to sensor gap. So i checked the gap on the o/s/r sensor which was flagging up a fault code and it did seem quite a large gap. I reduced the gap and it has solved the problem with regards to the ABS fault. I cleared all fault codes, test drove the vehicle and all is well. When i connected the vantage back up to the sensor after reducing the gap i did get somewhat of a signal but absolutley nothing like the reference waveform. Is it possible that different vehicles will produce completely different waveforms?


Jon.

Some will give you a square waveform and some will give you a sine waveform depending on the type of sensor it is. Not just ABS sensors but all sensors. Try using the "autofind" selection for CH-1. The machine will usually analyse the signal it's seing and give you a picture that you can then reduce/increase either the voltage or the time base to see it the way you want to.

[jonnyboy]

Thanks everyone for your help.....im trying to use the VP as much as possible on different vehicles to get used to using it and to see what waveforms are produced on known good sensors etc....have to say its a steep learning curve right now....definately not as easy as the snap on guy made it look.
I know snap on over here in the uk do day training courses on the different machines to give you an understanding of where to start from etc. Hopefully soon they will have a course for the VP as with it being relatively new in the uk they do not have as yet.


Jon.