2004 XC70 BCM-0031, -0021, -0012 after strut swap

[Herb Goltz]

Hi All,

I recently replaced all the strut assemblies on my 2004 XC70 with Monroe quick struts as well as all the sway bar end links. The fronts were straightforward, the rears were a challenge, as others here have described-- I destroyed a 2 ton come-along ratcheting down the control arms...

Since doing the job I am getting intermittent ABS codes, sometimes with an anti-skid message in the DIM, other times just the ABS light. I just got Vdash to replace VIDA, which no longer recognizes DICE after some Windows updates. It shows the following codes:

BCM-0031 Left rear wheel sensor signal faulty
BCM-0021 Right front wheel sensor signal faulty
BCM-0012 Left front wheel sensor signal faulty

I did remove the front sensors to protect them when unbolting the steering knuckles up front, but didn't touch the rears at all. I have pulled the front sensors and cleaned them carefully and reinstalled, but am still seeing the codes. I have not had the car aligned yet, as I discovered play in one tie rod end and need to order parts. Has anybody had a similar experience? What was the fix?

[scot850]

Other than damaging the wiring, did you remove the wheel hubs when doing the suspension or just the struts? I'm thinking that maybe the ABS tone rings may have got dirt or damage, but otherwise can't think how the 2 issues are related?

Neil.

[Herb Goltz]

Hi Neil,

I didn't remove the wheel hubs, just unbolted the strut from the steering knuckle, but not before removing the ABS sensors, because I was worried about damaging the sensor wires. I just tipped the knuckles outward enough to clear the struts and kept everything supported. I didn't touch the sensors on the back wheels at all. Strange to see 3 sensors with faulty signal all at once...

[Herb Goltz]

At this point the ABS light is on most of the time. I'm wondering if there is something more at play here-- it seems really unlikely that 3/4 ABS sensors (one of which I didn't touch) all failing intermittently-- should I be considering a BCM module failure? Steering angle sensor calibration? Anybody else encounter something like this before?

[vtl]

I had error like that when one of the front axle bolts became loose.

[Herb Goltz]

Thanks, I will check the axle bolts!

[scot850]

Do not re-use the axle bolts (stretch bolts) and make sure you torque them and then angle tighten them.

Neil.