Technical 2005 Ducato 2.8jtdABS pump working when breaking intermittent even when not required

[Tony31]

Hi all please can you help? I have an over active ABS pump that seems to activate regardless. I have read the ecm fault codes and theyre are non. The ABS warning light does not come on. But does come on when the ignition is turned on then goes off once it has done a system check. I have tried by replacing the front discs and pads plus I have pressure bled the front and rear brakes. I now have an amazing brake pedal however the ABS pump does come on when moving slow in traffic causing the pedal to judder. I have also tried removing the multi plug from the ABS ecm to see if there is any damp or corrosion on the pins.. Any idea will be concidered.

Many thanks


Tony31

 

[Ocwobio]

Hi. Had this on my Smart car some years ago. Problem came and went away once, then came back to stay. Only did it at low speed, brakes NOT applied, starting off or in traffic jam etc. and otherwise the ABS worked 100% normally at other times. Turns out it was rusty/broken reluctor rings on the back end, once replaced problem vanished and never came back, 7 years ago now. Could be that, tho' I think the front end has magnets in the wheel bearings, not reluctor rings? Someone will chime in soon, as this is the place to be....

If yours is a standard chassis/van, I don't know what the arrangement will be on the rear brakes- on mine it's discs front and back, standard IIRC is drums on the back. I guess it could also be caused by a dud wheel sensor too, but would expect a decent diagnostic tool to pick codes up; this does NOT always happen. The best tool is Multiecuscan paid version (free one may not do ABS system?), which I used when I got an ABS/EBD failure warnings on my MoHo based on the X224 Alko Maxi tag axle. However no codes showed up, just fail to connect to module.
IIRC the Fiat Ducato does not have the same type of reluctor rings as the Smart (which is the conventional toothed ring like a gear), but some other form, as stated. Presumablr, ABS works as expected when you provoke it?

(Mine was allegedly a broken earth wire somewhere, but never got a good explanation from the Fiat garage, was just glad to have it sorted!).