Polo Mk4 1.2 12v ABS sensor and drive shaft issue

[Phantome46]

I have a very strange issue at the moment which I am hoping somebody has seen before

I have recently had an issue with the polo - that required me to replace the passenger NSF drive shaft.

I purchased one from a breaker on ebay and it arrived. Compared it tot he one i took off and it look OK so I fitted it. Car worked fine - until i read tested it. ABS light came on.

Diagnosed it to NSF and then took out the sensor and sure enough it was worn right down like it was rubbing on something? (attached pic)

So I purchased a new sensor - installed and then drove the car and light went off.

Drove the car for about 5 miles and after about 4 miles ABS light came on - red brake light started flashing and then car was beeping at me.

Jacked it up and looked at new sensor and the side of the sensor has been worn away by rubbing on the drive shaft.

When i then looked through the hole that the sensor fits I have noticed that the drive shaft fitted has a very slight lip on it which steps up towards the engine side of the car and that is hitting the sensor rubbing it away.

Net result - i've broken a second sensor so am thinking must be an issue with the wrong drive shaft?

Can somebody help?

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3260_zpsfqnad6ue.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3260_zpsfqnad6ue.jpg.html)

[zollaf]

without seeing the drive shaft, i woudl say, that since there wasn't a problem with the old driveshaft, that yes, the new shaft is the wrong shaft. take it out and compare it properly to the old one.

[Phantome46]

without seeing the drive shaft, i woudl say, that since there wasn't a problem with the old driveshaft, that yes, the new shaft is the wrong shaft. take it out and compare it properly to the old one.

I have removed the current shaft and very carefully compared it to the old one and they are exactly the same - length, profile etc. so I refitted it. I added a small bit of car body filler to the bottom of the old sensor to build up the original shape and then refitted it. I turned the wheel and it was slightly rubbing. so i removed it and then removed the drive shaft and this is what I'm seeing

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3280_zpsbpucv2se.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3280_zpsbpucv2se.jpg.html)

Only a very small portion of the sensor plastic is touching the drive shaft and it wears a few mm off the corner of the sensor and then seems ok? Is this normal - i doubt that the sensors are designed to wear down to the correct position to ensure optimum gap? But other than that I'm stuck?

[micheal balbrig]

How does the sensor get its signal on your car.?

[Phantome46]

How does the sensor get its signal on your car.?

absolutely no idea to be honest? think its a magnetic pulse from D/S to sensor - but this is exactly the same as it was before it was dismantled

[Phantome46]

Has nobody come across this issue before? I was hoping for some tech expertise to help me solve this one?

Thanks

[micheal balbrig]

As Zollaf said earlier it may be a different shaft although looking similar.
Do you have the old c/v joint to fit in to see if it runs free in the unit,This would be only for trial.

[zollaf]

post up 2 pics, one of the old shaft and one of the new one. incidentally, the shaft pictured doesn't have a reluctor ring fitted so isn't compatible with abs anyway ??

[Phantome46]

just run code reader to understand the current fault and have 2 codes:

1 - 00283 -
































00283



P1711



ABS Wheel Speed Signal #1 (Left Front) - Range/Performance - G47



















































































































































































































2 -
















00597



P1728



Varying ABS Wheel Speed Signals - Range/Performance

[zollaf]

pics of the original shaft ???

[Sam]

pics of the original shaft ???

https://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Richard_Roundtree_1973.JPG/180px-Richard_Roundtree_1973.JPG

[zollaf]

love it...

[Phantome46]

pics attached

original one:

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3319_zpsqlvomnv6.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3319_zpsqlvomnv6.jpg.html)

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3318_zps2zynrbdi.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3318_zps2zynrbdi.jpg.html)

Replacement 1:

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3320_zpstvn2txew.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3320_zpstvn2txew.jpg.html)

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3321_zpsyuhhiiko.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3321_zpsyuhhiiko.jpg.html)

Current one on the car
http://i16.photobucket.com/albums/b8/Phantome46/IMG_3280_zpsbpucv2se.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3280_zpsbpucv2se.jpg.html)

They are all identical! and yet the new speed sensor on that side seems to rub a little and wear back on one corner? as i cannot get the RHS one out I cannot compare it.

[zollaf]

well thats me proper stumped then. :confused:

[Phantome46]

have you seen the corner wear from the speed sensor before? its not exposed any contacts so maybe thats normal? as i would guess gapping is important?

[zollaf]

well no. a speed sensor normally runs against a reluctor ring rather than just the cv joint. what year is your polo ?
and no, a littlem wear on the end won't or at least shouldn't matter. normally you either just secure the sensor in place but some you push down onto the ring and let them find their own position.

[Phantome46]

54 plate so 2004 mk4 1.2 12v twist

[RufusReject]

Looks like there is a piece missing from both drive shafts to me, isn't this what it should look like:
http://i.ebayimg.com/00/s/NzAwWDEwMDA=/z/XT8AAOSw5ZBWHpZh/$_57.JPG
How the original one didn't throw up any ABS problems I do not know though. Perhaps the 'original' drive shaft was from a car with no ABS and somehow managed to avoid throwing codes?

[Phantome46]

No the plastic guide ring sits inside the hub and connects to the drive shaft the speed sensor runs between the plastic ring and the CV boot on that angled piece which would suggest that the corner will wear?

Mine has that fitted and so did the old one?

Still confused about it all

[RufusReject]

Ok, do you know if the replacement drive shaft was definitely from a car with ABS?

[Phantome46]

yes its identical to the one i took off.

I just reset the lights and took it out for a drive and ABS light pings on in about 3 secs of driving.

fault codes 00283 and 00532.

I can hear a sort of rubbing sound from the passenger front side every now and then when you go over a bump but not all the time - but having had the car apart 3-4 times i am pretty certain the drive shaft is tight - torqued up to correct setting and everything is running true?

[RufusReject]

Did you use the original hub nut on the end of the drive shaft or one that came with the replacement shaft/ are they identical?

Wheel roller bearings - assembly overview (http://workshop-manuals.com/volkswagen/polo-mk4/running_gear_axles_steering/front_suspension_drive_shafts/ii_wheel_roller_bearings_repair/wheel_roller_bearings_assembly_overview/)

Here they seem to be different.

[Phantome46]

Fitted the same nut as came off the car and the same as in your picture. Identical

And torqued up to the same numbers

Is there a bed in procedure for Speed sensor? as my light comes on as soon as the wheel spins and does not go out


Looks like there is a piece missing from both drive shafts to me, isn't this what it should look like:
http://i.ebayimg.com/00/s/NzAwWDEwMDA=/z/XT8AAOSw5ZBWHpZh/$_57.JPG
How the original one didn't throw up any ABS problems I do not know though. Perhaps the 'original' drive shaft was from a car with no ABS and somehow managed to avoid throwing codes?

[RufusReject]

Not according to this:

Front axle speed sensor - remove and install (http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/front_axle_speed_sensor_remove_and_install/)

Are you sure the wheel bearing is ok? My only thought now is that slight play here would allow the drive shaft to wear the sensor.

The ABS sensor ring is in the wheel hub as it says here:

http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/

I guess the next step could be to look at the hub but seems strange when all this started after replacing the drive shaft. Can you connect a multimeter across the pins of the damaged sensor, at least that would give an idea of whether the sensor is no longer functioning due to the damage or it is the fact it is not in exactly the right place relative to the ABS sensor ring that is causing the problem. I think basically if the meter indicates an open circuit across the sensor then it will not work but perhaps someone else can confirm this will be the case here?

[Phantome46]

Thanks for this - what setting shall i set the multi meter to? and do i need to spin the hub whilst i'm doing it?

I am in the same place as you - light was not on and has only come on since taking out a damaged Speed sensor?

Thanks

[RufusReject]

There should be a setting for just testing continuity, this will indicate if the circuit in the sensor has been broken by the wear on the drive shaft.

[Phantome46]

Maybe I need to replace this ring as its damaged? would this cause a problem? not sure how as its only plastic so would not stop the drive shaft being installed properly?

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3278_zpspt1ox8jq.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3278_zpspt1ox8jq.jpg.html)

[Phantome46]

any ideas of the part number and how much they cost? this is my last hope of getting a fix?

[micheal balbrig]

Are they copper segments in the plastic,just wondering if that could be the signal pick up for sensor.
Does the ring shown turn with the c/v joint?
Sorry for more questions than answers.

[Phantome46]

I have just tried to carry out a continuity test across the sensor and something weird happened?

When you touch the terminals of the multimeter together you get the beeping. Then when you touch each terminal on the speed sensor I get a figure appear on the multimeter but no beeping?

Any idea what i'm doing wrong?

http://i16.photobucket.com/albums/b8/Phantome46/IMG_3331_zpsy6nrjusb.jpg (http://s16.photobucket.com/user/Phantome46/media/IMG_3331_zpsy6nrjusb.jpg.html)



Not according to this:

Front axle speed sensor - remove and install (http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/front_axle_speed_sensor_remove_and_install/)

Are you sure the wheel bearing is ok? My only thought now is that slight play here would allow the drive shaft to wear the sensor.

The ABS sensor ring is in the wheel hub as it says here:

http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/http://workshop-manuals.com/volkswagen/polo-mk4/brake_systems/abs_adr_tcs_edl_esp/abs_system_components_on_the_front_and_rear_axles_ remove_and_install/remove_and_install_the_front_axle_abs_system_compo nents/

I guess the next step could be to look at the hub but seems strange when all this started after replacing the drive shaft. Can you connect a multimeter across the pins of the damaged sensor, at least that would give an idea of whether the sensor is no longer functioning due to the damage or it is the fact it is not in exactly the right place relative to the ABS sensor ring that is causing the problem. I think basically if the meter indicates an open circuit across the sensor then it will not work but perhaps someone else can confirm this will be the case here?

[micheal balbrig]

Is it possible to swap over the sensors to see if problem swaps over as well.
Like yourself I am no expert on electronics,but maybe the test on sensor should be with an ohms test.

[Phantome46]

Tested the original sensor that had the metal exposed and i cannot get any reading at all. i then tested the sensor thats currently in there and get this figure. plus now have a brand new sensor never fitted and tested that and get the same reading - so i'm guessing that they are OK?

Just refitted after taking calliper and disc off and checking the metal ring that sits around the hub - made sure it was seated properly and put back together. reset light - reversed backwards and after about 3 wheel revolutions light back on!

I am pulling my hair out now with this car and just don't know what to do!

[Phantome46]

no its all hard plastic problem was i inserted it the wrong way and it rubbed between the drive shaft and hub itself. I took it out and fitted it the right way round and it seems ok now. cannot see how this plastic ring can be anything to do with the Speed sensor at all? unless it measures magnetic pulse from the side f the sensor and against the ring itself?