ABS warning lamp

Hi guys/gals hope somebody can help, I have a 2001 323F 2.0 sport FS 16V engine.
 
Abs stabillity control and tcs off lights all on, get the error code Hydraulic pump motor o/c (1096)
 
I dont think this is the fault, as it is intermittent, when the fault is not there, then the abs works fine????
 
I have been using a Mazda tech star diagnostic machine on the obdII plug, to get the fault code.
 
I did a rolling data test, the warning lamp does not come on untill the Left Front Wheel Speed Sensor reaches 10 KPH, at this time all the other sensors are doing 11 KPH.(pointing to that sensor maybe?)
 
on the road in a straight line at a steady speed the Left Rear Wheel Speed Sensor reads consistently 1 KPH slower than the other three.
 
I have phoned my dealers, but they were not very helpfull, I have checked all the plugs etc everything appears fine.
 
Does anybody know of any common faults on these particular models?
 
Any help appreciated, or if anybody has had a similar problem please let me know, cheers.
 

IMHO the difference of 1 KPH should not turn your ABS light ON. Also, according to my 626 workshop manual, ABS completes its self test only when the speed becomes more than 10 KPH. So, it seems to me that you have some other reason for the fault and not 1 KPH difference.
 
But if the fault is intermittent then it is usually sensors. You may therefore disconnect suspect sensor and check its resistance which should be 1.4 - 1.8 kOhm. Also check the clearance between the sensor and the rotor which should be 0.3 - 1.1 mm. And better do that for all the four sensors.

Cheers for the reply, i did the resistance checks and they were all around 1.5k but i will check the gaps.