ABS/traction control fault

Hi all
I have had this fault for a while now, took it to a garage that mainly works on Land rovers and Range rovers, he pluged in his test box and it came up with a front sensor fault, i replaced the sensor for a genuine L/R one, this didn't fix the fault straight away, but after a couple of days it started working as it should, this was fine for about a month then the ABS/traction control lights and warning came up on the screen again.

It has been taken back and plugged in again and now the fault is (same signal from different sensors) the mechanic says that the control box is faulty.

I have removed the unit, checked the plugs etc, refitted still same, number on the unit is srd100501, this is a 1999> 4.6 thor engined p38, i have searched through and from what i have read, that this is an already upgraded unit, so i suppose what i am asking is, has anyone had this same fault, did changing this unit cure the problem, at £600 from L/R and £230 elsewhere (found while searching) is it likely to fix the problem.

Cheers
Ian

Usual fault is too large an air gap at sensor or plugs to loom need cleaning. Push sensor in until it is touching reluctor ring and leave it there, it will set when wheel turns. Other problem could be a wheel bearing worn allowing sensor to be pushed back too far. You will also get this if air gap is too large and you have low battery voltage.

cheers Wammers
I have managed to get a Numax 110 amp 1000cca battery in the battery box, it's been in there about 4 months and it spins the engine over very well, so i am sure the charging is Okay.

As for a wheel bearing, i supopose it might be, something is not quite right with the front end, but i have found a couple of radius arm bushes gone, only went through MOT 4 months ago.

Ian

Just checked battery voltage 12.2v but has been stood 48hrs, run up and went right up to 14.4v, i live very close to a 24hr petrol station, so i think my becm is kept awake