ABS issues

[hausmeister]

On the s70 I had the rear sensors failed one time. I remember I was able to get into the ABS on an obd2 tester and check the live data of the sensors, and one wasn't reading. It is not always the computer.
Replacing sensors with cable was a pain though with routing the cable.

[bcfischer]

The swap on the rings/sensors was the last step in a project that involved replacing both hubs/bearings, so I am overly familiar with the nuts and bolts to which you refer. Every bolt on this project was a complete war. I will check that everything is to spec, particularly the axle nut as it affects the relationship between the ring and the sensor. I will also ohm test the sensors.

Thanks for the good counsel!

[bcfischer]

I have re-torqued the axle nuts. ABS light is still on, but I have not brought it up to speed yet. I am reading about 800 (798 to 801) Ohms from each sensor. I am testing from the distal harness, not the main one right below the module. I believe that the range is 900-1380. Thoughts? Most of the people complaining about ABS problems have high resistance readings, not low ones.

[abscate]

Resistance is only useful marker for ABS sensors if it’s infinite.

A scanner revealing wheel speed will tell you if the sensor is behaving.

[Matty Moo]

At this point you can have an ABS module fault and one or more faults outside of the module. It comes with the age.

I tested twelve 96-98 abs modules last week, 5 of the 12 had codes showing faults outside of the module on whatever car they came from.

[bcfischer]

I now have a beautifully repaired ABS module from Matty Moo, new sensors, and new rings. The sensors show resistance (but no infinite resistance - 'resistance is futile') from the sensor wiring harnesses. The module stored a couple of codes that Matty Moo said were not related to an issue with the module. Both are related to the right front sensor, no signal and intermittent signal. I tested the circuit from the ABS main harness to the sensor harness on that side. I get completed circuits from sockets 18 and 19 (17 is empty) one to one socket on the sensor harness and one to the other. The wires are yellow (socket 18) and black (socket 19).

Are these the appropriate pinouts for a late-year 1999 V70XC? I have a diagram from Matty at Midwest ABS that indicates sockets 3 and 18 should be the right front, but that is for a slightly earlier batch of V70s.

Brian

[FireFox31]

For what it's worth, the front speed sensors on my working 2000 V70 read 13.9 M ohm. On my faulty 2000 V70, they read 13.5 M ohm (good right) and 14.1 M ohm (bad left). I don't think any of those resistance values are a problem because VIDA shows decent data from the speed sensors. The cut-outs in the front left were rusty reluctor rings.

Perhaps the phrase is "resistance is useless."

[abscate]

There was a pinout diagram for the -1998 here but the 1999 is different, be aware.