HELP With Brakes. Topic is solved

[seggs]

Following up on my abs sensor adventure. I did find a sensor that “works” but was reading wheel speed erratically…going down the road it would jump back and forth from 0 to random speed values. Pulled the working sensor from my other daughter’s 2008 s60 and swapped it with the 2009 S60’s sensor and same result. Knowing then that was not a sensor issue, in desperation I cut out the harness and soldered the wires directly. Still, same result.
So, I can only guess it’s some flaw in my abs module?? Anyone have this same experience?

One other thing that’s could be a factor…the I’ve had the typical problem with the steering angle sensor for the past year setting off the DSTC service light. However, it had never set off the ABS light in the past. I was intending to replace the clockspring before this issue came up, however, if I can’t get an accurate speed reading on one of the wheels, I’m feeling like it’s a waste of of time. Still I wonder if somehow in the code it’s all connected somehow. Any insights?

[scot850]

Are the reluctor rings all good? If they get junk in them or get corroded badly they may not read correctly, and worst case they can crack.

Neil.

[seggs]

Thanks for the advice. Well, this is a FWD car, and since there are no axels in the rear, the mechanism that the sensor reads from is buried in the bearing, so no way to check it that I’m aware of. If you read earlier in the post, I had replaced the bearing just before the sensor stopped working. I switched it back thinking it was the culprit. I guess it’s possible that the sensor went bad, and the old bearing mechanism too. I know I now have a good sensor now, so plan to put the new bearing back in. Crossing fingers.

[Vova585]

Seggs, try swapping connectors between right and left wheel. You may need to create a "bridge" between currently right wheel sensor and left wheel connector and similar to the other side. Now, after assuring that everything is color coded and connected ok, erase stored codes in abs module. Turn car off. Restart the car and check for codes. If no codes- your "bridge job" is likely ok. Turn speed graff function for rear wheel and start a test drive. If previously bad wheel(RR I think it was) now reports great and previously good side(LR) now has issues with dropping the signal- congratulations the issue is not in the module or wires-it is a hub. In such case I would ask myself where I got it from. A lot of times aftermarket may do good job with metal, but not with magnetic reluctor rind located inside. In such case I would order vin specific hub with new dust shield and bolts and replace it. Hopefully your problem is gone for good now. If after swap of the wires from side to side, problem still remains localized to RR-one can inspect pin tension at the connectors gping to the abs module/module itself. Tiny needle and not screwdriver here. One can open the abs module connector and swap right and left rear wheel inputs. Reassemble and retest. If the problem still in RR wheel- module.

[jimmy57]

the speed sensor reads the rubber seal face on the rear hub wheel bearing. The seal has 48 magnetic "spots" on it. If that got hot and the seal piece fell out or detached from the spindle, then there is no magnetic pulses passing by the sensor. Make sure that seal moves when you turn the hub face.

[seggs]

Thank you for the comments & help.
I finally have solved this after replacing the bearing. The best I can tell is that in the process of removing the old bearing the first time. The seal that jimmy57 mentioned must have become dislodged. Being that it was 17 years old, it took some persuasion get it off of the knuckle, which is likely what caused it. The seal must have been loosely following the bearing rotation, but not fully, leading to the erratic readings.
Anyway, all is good now. Thanks to all for the help. On to the next project.