Hey guys, I have a 08 Burb. I replaced my rear abs sensors a while ago and now have the abs light on. I checked the code and found it is the left rear sensor. I replaced it again and still same issue. I switched the right and left and still the left is bad. I did replace the rear diff and rear wheel bearings when I originally replaced the rear abs sensors. Could this be something to do with the axle?

 

did you install an axle with the same ratio as original?

 

I made sure to install the axles back on there same sides so nothing has changed there

 

I was talking about the ring + pinion. So you only replaced the differential carrier and spider gears?

Other than that, it could be a fault in the wiring or connectors.

What was the exact code you got?

 

oh okay, yeah, just the carrier and spider gears. The code is c045 and u0121.

before I changed the sensors the first time I would get a traction control light flashing every time I turned. Not sure if that’s related

 

Code U0121 means Lost Communication with Anti-lock Brake System Module.

So you've got some wiring issues or a failed module.

As for the wheel speed sensor ...

• wiring issue
• Debris on the wheel speed sensor or the encoder ring
• Loose or improperly mounted sensor
• Air gap between the wheel speed sensor and the encoder ring too large

There are ways to measure and verify the sensor if you search the web.

 

It looks like there is a bigger gap on the side im getting the code. Between the sensor and ring.

 

Update. Since this issue I swapped the right with the left sensor and cleared the codes but LR still pops up. I replaced the abs module and still same issue. I only get the LR code though. Other issues Ive noticed since is that the clunking in the rear is a bit louder, Im 99% sure its the rear axles sliding a bit. Also I dont have a brake light on ever, just he ABS and traction control lights stay on.

 

why would the axle slide? It should be captured by c-clips. Clunking is usually wear in the driveline.
You said the sensor gap was bigger on the LR. That's what you need to fix. The gap is critical. Clean off the hub surface really well until you nothing but smooth clean metal.

 

From what I understood the axles will always have a tiny bit of play, if they didnt you wouldnt be able to remove the c-clips.. Not sure why mine are so loud though. Ive removed the rear sway bar with no change in clunking. Replaced the rear track bar, upper/lower control arms but no change in noise. Ive cleaned the tone ring a few times with no change. Just curious why would one side have a bigger gap than the other? Seems like the tone rings look the same as far as width and of course the abs sensors are the same length. Thanks again