N/S/F abs sensor reading over 1000mph.

Customer phoned up and complained of the abs cutting in at low speeds, no problem I said come on in.

Road tested vehicle and confirmed fault, scanned abs module for codes non present. Looked at live data and saw the n/s/f sensor reading over 1000mph.

Raised vehicle and looked at abs ring expecting the normal cracked ring. Ring was in good condition with an acceptable air gap to the sensor.

Made a quick decision to change the sensor. Sensor fitted no difference.

I then checked the wiring from the sensor to the module which checked out fine. Also ohm checked all the sensors at the module to check that I didn't have a faulty new sensor. All good.

I then used the scope and checked the wave forms directly at the module plug. The sensors and abs rings are producing good quality square waves.

At this point I advised the customer that we're looking at getting a abs pump/module. I must add that all powers and grounds were tested, grounds were cleaned and a drag test on the connector was done to make sure we had good contact between plug and module pins. New wiring was also made up between the sensor and the module to discount any chance of bad wiring.

Ordered and fitted a second hand abs unit and you guessed it absolutely no difference. I have no direction with this now and am looking for a bit of advise/out of the box thinking.

Thanks in advance

Nathan