Year of Manufacture *: 2005
The car came in with a fault code for N/S/F abs sensor. Did a test drive and viewed live data with Snap_on Modis scanner. The light would come on as the wheel speed on N/S/F dropped out intermittently but quite frequently.
Due to reasonably cheap cost of sensor (£40) I replaced sensor. Now I am getting no speed signal at all from N/S/F. My first thought faultly sensor, so put another on. Same result.
I then put scope into ABS ecu to see signal patterns. It is a Active type abs sensor (12v feed from ECU and earth connection, the resultant signal moves ever so slightly around the 12v. With scope data from both front ABS sensors, the patterns were both fine. But car data still sees no speed from N/S/F in live data.
Ok thoughts turn to faultly ECU. Next step check continuity and resistance of n/s/f and o/s/f abs wiring looms to ecu. both fine and record same values. I then used jumper wires to connect O/S/F abs loom to N/s/F sensor. I got live data via the Modis and car was seeing signal. So this tells me N/S/F ABS sensor and N/S/F abs wheel bearing are ok.
Points towars a faulty n/s/f loom. So I then got jumper wires between O/S/F sensor and N/S/F loom. I get back good live data from MODIS. Confused.
I then used jumper wires to connect the looms and sensors in opposite way (n/s/f loom to o/s/f sensor and vica versa). I get good live data readings and lights stay off dashboard. This proves sensors good, bearings good, loom good, ecu good. However, when I plug n/s/f sensor into n/s/f loom no readings????
I am very confused. Any ideas?
Copyright © uk autotalk