Technical ABS warning light on dash

[Ducatomick1988]

So I’ve got a 2.3L Fiat ducato 2011 (61 plate) A while back my ABS light came on the dash, I replaced all 4 sensors, to no avail, the light was still there. When I took the van to get an MOT I told them to check it out, the turned the light off for the test and said it was coming up on the diagnostic machine drivers rear.. he said to me in the past he has found changing the sensor for a genuine part sometimes does the trick, I’ve just fitted a second new genuine sensor and the light is still on, has anyone came across this and if so is there any advice?

 

[bugsymike]

So I’ve got a 2.3L Fiat ducato 2011 (61 plate) A while back my ABS light came on the dash, I replaced all 4 sensors, to no avail, the light was still there. When I took the van to get an MOT I told them to check it out, the turned the light off for the test and said it was coming up on the diagnostic machine drivers rear.. he said to me in the past he has found changing the sensor for a genuine part sometimes does the trick, I’ve just fitted a second new genuine sensor and the light is still on, has anyone came across this and if so is there any advice?

If the error code reader says drivers rear for sure then the most likely cause is the ABS reluctor ring on that wheel, earlier vehicles used a visible ring and a different sensor to read it.
Most nowadays use a magnetic ring that is part of the inner end of the hub bearing, generally if not interfered with they keep working, however if a ABS sensor is fitted and someone rams a magnetic screwdriver down the hole to clean it out, or if any thing magnetic has been in contact with that magnetic ring then the bearing is scrap and will need replacing.
Less likely but not impossible is a break in the wire from the ABS unit under the bonnet in it's wiring to that individual rear sensor.
Check for exact details but there should be a reading of battery volts between the two wires in the sensor plug. I had a 4x4 Skoda with a voltage reading of 11 volts on one side front and working , but on the other side it read 8volts due to a wiring fault hence error code.
Read up about it before testing to prevent damage!
If the error code is deleted, but comes on as the vehicle moves off then it would point to the magnetic bearing, if a "Active" ABS sensor, one that needs a voltage in and out.
A good diagnostic tool will read all ABS sensors at the same time so it is possible to see for sure where the fault is.

 

[Ducatomick1988]

If the error code reader says drivers rear for sure then the most likely cause is the ABS reluctor ring on that wheel, earlier vehicles used a visible ring and a different sensor to read it.
Most nowadays use a magnetic ring that is part of the inner end of the hub bearing, generally if not interfered with they keep working, however if a ABS sensor is fitted and someone rams a magnetic screwdriver down the hole to clean it out, or if any thing magnetic has been in contact with that magnetic ring then the bearing is scrap and will need replacing.
Less likely but not impossible is a break in the wire from the ABS unit under the bonnet in it's wiring to that individual rear sensor.
Check for exact details but there should be a reading of battery volts between the two wires in the sensor plug. I had a 4x4 Skoda with a voltage reading of 11 volts on one side front and working , but on the other side it read 8volts due to a wiring fault hence error code.
Read up about it before testing to prevent damage!
If the error code is deleted, but comes on as the vehicle moves off then it would point to the magnetic bearing, if a "Active" ABS sensor, one that needs a voltage in and out.
A good diagnostic tool will read all ABS sensors at the same time so it is possible to see for sure where the fault is.

Thanks for the reply, Mike.

Is it possible to buy just the magnetic ring or would it be a full hub bearing jobby?

 

[bugsymike]

Thanks for the reply, Mike.

Is it possible to buy just the magnetic ring or would it be a full hub bearing jobby?

If it is in the bearing then a new hub bearing is required, so obviously test it first to be sure.
Any break in the readings will mean it is scrap.
I am lucky enough to have an ABS detector from the SKF bearing people.

 

[Steady1234]

So I’ve got a 2.3L Fiat ducato 2011 (61 plate) A while back my ABS light came on the dash, I replaced all 4 sensors, to no avail, the light was still there. When I took the van to get an MOT I told them to check it out, the turned the light off for the test and said it was coming up on the diagnostic machine drivers rear.. he said to me in the past he has found changing the sensor for a genuine part sometimes does the trick, I’ve just fitted a second new genuine sensor and the light is still on, has anyone came across this and if so is there any advice?

Have you taken it for a drive, you have to drive it for it all to reset

 

[bugsymike]

A good diagnostic tool or testing with a volt meter may give a better idea of where fault lies if it is still on.