I’ve got a strange one I can’t nail down.

2007 Buick Lucerne 3.8l.

Codes Present
P0449
P0327
P0332
P0443
P0449
C0050

For this post, I'm just concerned about the C0050. The rest is just so we have the full history.

When it’* cold wet out (seems to be the most often this happens), the service traction control light and service brake assist lights come on. I pulled off the right rear wheel. Turns out the brake caliper was bad. I replaced the rear pads and the right rear caliper as well. I had replaced the left rear caliper about 6 months ago as well. While I was at it (and because they were bad) I replaced both rear wheel hub assemblies. I bled the brake caliper, (only at the caliper, not with the scan tool), cleared the codes and set off for a road test.

The brakes work great and feel good, although am getting an ABS activation in the pedal when I slow from 40-0mph. It doesn't happen all the time, but frequent enough to concern me. It is always at slow speeds (below 10mph) and it happens when NOT necessary, as in the roads aren't slippery. I'm still getting the C0050 code. My next thought is the wiring that goes to the right rear wheel hub. Could I simply cut the two wires that go the the plug and replace 2-6 feet or so of the wire? It seems to be in some sort of hard molded coating, so I can't just peel back the split loom to inspect it. Where does this wire go? I don't have a lift so I'm rolling under it. Could this be causing the code and even the strange ABS activation at low speeds?

Detail: The ABS at low speed activation did not happen until I replaced the rear pads, right rear caliper, and both rear wheel hub assemblies, the code was present before that, but the pedal did not pulsate at low speeds until this work was done.

Thanks for any help!

You have a bad hub.

I would agree with the exception of the fact that this is the second wheel hub in 6 months and I get the same code even after replacing.

What brand did you use?

WJB WA512003

I don't know anything about WJB except that they're super inexpensive on Rock Auto. You could try swapping hubs from side to side to see if the problem follows. If you truly want to diagnose, plugging in and watching both rear wheel speeds on a scanner would probably tell you where to look, and where the problem goes as you change parts around.

What brand would you recommend?

1. Timken
2. ACDelco
3. Mevotech (I haven't installed a lot of their hubs, but I have installed a lot of their suspension parts and all of it seems good quality and has worked a long time with no issue.)

There are a couple of other older formerly trustworthy brand names there, but I hear rumors of the names being bought to stamp on cheap parts etc. and/or have seen it personally and I haven't kept track of where that'* happened. If there were no Timken, I'd probably do more research on that.

Update:

I was able to track down the C0050 issue. I traced the wire from the right rear wheel to the trunk. I checked continuity between the two areas and had no continuity in either wire. I replaced the entirety of the two wires from the sensor to the left rear corner in the trunk where the wires enter. Gray with a blue tracer and brown. This fixed the C0050 issue. I do still however have the issue of the brake pedal pulsating at low speed stops. I'm wondering now if that could be as simple as a small amount of air in the lines, and using a scanner to bleed the brakes may help? The ABS works great, after testing it out quite a bit on a gravel road.

Pulsating like the ABS is doing its thing or pulsating like warped rotor?