Technical Abs light on after replacing front left wheel bearing and abs sensor

[Declan Fiat]

I have a 2009 1.3 multijet with 180000 miles. Just changed front left wheel bearing and sensor.
Now the abs light comes on when you hit 35mile on speedo and stays on. Grage checked and can see speed difference on left wheel versus right wheel.
Changed sensor same.
Cleaned connections at ABS unit.
Visual checked wires no issue.
Disconnected battery for a time same.
Took sensor out and cleaned the slot .
Is the solution to replace the drivers side with same bearing and sensor?

 

[varesecrazy]

I have a 2009 1.3 multijet with 180000 miles. Just changed front left wheel bearing and sensor.
Now the abs light comes on when you hit 35mile on speedo and stays on. Grage checked and can see speed difference on left wheel versus right wheel.
Changed sensor same.
Cleaned connections at ABS unit.
Visual checked wires no issue.
Disconnected battery for a time same.
Took sensor out and cleaned the slot .
Is the solution to replace the drivers side with same bearing and sensor?

Hi

Not had to do a bearing on a punto since the 188 mk2's.. but they didnt have an ABS rotor.. they just just had a pick.up in the bearing.

Was yours this type?

It only flagging a fault after a certain speed / Distance makes me think its a 'Reading error'

 

[Declan Fiat]

Hi

Not had to do a bearing on a punto since the 188 mk2's.. but they didnt have an ABS rotor.. they just just had a pick.up in the bearing.

Was yours this type?

It only flagging a fault after a certain speed / Distance makes me think its a 'Reading error'

Hi
It reads the bearing .

 

[varesecrazy]

Hi
It reads the bearing .

So there is NO ROTOR?

 

[Declan Fiat]

Varesecrazy
No rotor.
Basic wheel bearing with built in abs ring.
I have a lot of time spent on this and it has me baffled.

 

[portland_bill]

If you can see a reading on both wheels, but they are different, this suggests that the new bearing has a different number of triggers in it than the original.
Or, the new sensor is reading differently.
I'm guessing the sensor was replaced due to it being damaged removing the original, as it will have been in there a long time. Swapping the sensors across the car, if possible, might help to diagnose. Or refit the original sensor if possible. That could determine if the sensor, or bearing is the problem.
If the bearing is the problem. Choices would be:
1. Demand a correct replacement, and as the job has to be done again, ask for some labour costs. That still leaves the other side as original.
2. Replace the other side bearing to match. That gives you new bearings both sides. BUT! You may then have a mismatch front to rear, as the front wheels may appear to be rotating slower than the rears.

I wonder if the bearing reluctor ring changed at some time, and the aftermarket supplier does not know. If you still have the old bearing, is it possible to count the reluctor lines in the seal? If you have some iron filings, put the bearing reluctor upwards on a flat surface. Put a thin piece of paper on the bearing
and sprinkle the iron filings onto it. Gently blow across, and they should show a pattern, so you can count them.

 

[irc]

Varesecrazy
No rotor.
Basic wheel bearing with built in abs ring.
I have a lot of time spent on this and it has me baffled.

Never had it happen myself, but I have heard of a similar problem when the magnetic ABS ring on the bearing was believed to have been affected by a magnetised screwdriver or similar prior to fitting. Or possibly it was just faulty out of the box.
Fix was to replace bearing again, which was how I got involved.
EDIT: Post crossed with above.

 

[Declan Fiat]

Varesecrazy
No rotor.
Basic wheel bearing with built in abs ring.
I have a lot of time spent on this and it has me baffled.

If you can see a reading on both wheels, but they are different, this suggests that the new bearing has a different number of triggers in it than the original.
Or, the new sensor is reading differently.
I'm guessing the sensor was replaced due to it being damaged removing the original, as it will have been in there a long time. Swapping the sensors across the car, if possible, might help to diagnose. Or refit the original sensor if possible. That could determine if the sensor, or bearing is the problem.
If the bearing is the problem. Choices would be:
1. Demand a correct replacement, and as the job has to be done again, ask for some labour costs. That still leaves the other side as original.
2. Replace the other side bearing to match. That gives you new bearings both sides. BUT! You may then have a mismatch front to rear, as the front wheels may appear to be rotating slower than the rears.

I wonder if the bearing reluctor ring changed at some time, and the aftermarket supplier does not know. If you still have the old bearing, is it possible to count the reluctor lines in the seal? If you have some iron filings, put the bearing reluctor upwards on a flat surface. Put a thin piece of paper on the bearing
and sprinkle the iron filings onto it. Gently blow across, and they should show a pattern, so you can count them.

Sensor was damaged as old and stuck. Had to break to get out. Swapping will bring same issue as right side will have same issue stuck with age.. Do all my own work bar pushing the bearing out as my mate did it for me.

 

[Declan Fiat]

Sensor was damaged as old and stuck. Had to break to get out. Swapping will bring same issue as right side will have same issue stuck with age.. Do all my own work bar pushing the bearing out as my mate did it for me.

Ok , update, problem solved. The Mechanic that took out the old bearing and replaced the new one damaged the magnetic strip . He was the cause of the whole issue. I bought a new bearing , jacked up the car , took off only the wheel and the big cv drive bolt, pushed in the drive and took a look at the back of the bearing and could see that the magnetic strip was lower that the outer side of the bearing. Got that bearing taken out, new one in, and hay presto no ABS light ... Thanks for your comments, hope this helps someone.