How To: Service/Replace ABS Wheel Speed Sensor

[Freedom Motorsports]

I am not sure off the top of my head which torx bit it is for the sensor, I believe it may be a T25. As for the issue, in a lot of cases, it is simply a matter of corrosion causing a loss of communication between the sensor and the magnetic gear inside the hub. I personally use Rustoleum brand paint, it is goof for protection against future rust. But don't put a lot, only a light coating, too much and you will recreate the issue with paint instead of rust.

 

[miscrap]

Thanks for the write up! My '05 Tahoe Z71 has started giving me a Traction Active light, along with no power until I get off the gas, when starting from a stop. I also get a groaning noise just before coming to a stop. These things happen once every few days. Does this sound like the issue you're talking about?

After reading the thread, I have a few questions. At first you mention that you use a rust preventing LUBRICANT, then you say PAINT (Rustoleum). At first I was thinking of wiping it with an oil of some kind, now I'm not sure.

Also you said "Plug the hole on top of the hub bearing with something to keep debri from getting into the wheel hub bearing. Then use a heavy wire brush, course sand paper or wire wheel in a grinder or drill to clean the corrosion off ot the top of the wheel hub bearing." So we don't want stuff getting into the wheel hub bearing, but we're using a wire wheel on the wheel hub bearing? I'm confused. Is the wheel hub bearing beneath the hole that we're plugging, or is it the area we're cleaning? Are we plugging the hole from the screw or the sensor? And is the picture with the black rectangle the correct area to clean?

Sorry for all the questions. I was just about ready to order a hub/bearing assembly, but this would be a lot easier and cheaper! Thanks again!

 

[Freedom Motorsports]

Sorry about the lubricant statement, it is paint. But with plugging the hole on the hub bearing before cleaning, you can plug the screw hole if you want to, but the hole that really needs plugged is the sensor hole. You don't want debris falling into the hub bearing and getting on the magnetic gear inside the hub.

It is possible that this could help your issues, but the one thing that I never experienced with it is power loss. At times with some trucks I have seen where you can feel the stability control kick in while moving, but not much of anything from a stop. The groaning noise could be the hub bearing, but if it is then the bearing is probably bad and performing this maintenance will not help. Once the hub bearing has gotten bad enough to "grind" then it is too late and the hub bearing needs to be replaced.

 

[doylee4693]

my truck just had its sensor cleaned for the 3rd time since new,im wondering why not just but an aftermarket sensor?wouldnt it work better then cleaning the faulty gm sensor and getting it again in another year or two?

 

[doylee4693]

BUMP (my abs sensor is going to need help again soon)...any reason why we cant correct the problem by getting an aftermarket sensor?is it built into hub so cant replace just the sensor?

 

[Freedom Motorsports]

I don't think there is an aftermarket option for that sensor. But you can order a new sensor from the dealer without the hub bearing, but if you order a bearing it comes with a new sensor. But to test the sensor itself, you can unplug the harness side of the sensor and test with a meter to be able to tell if the sensor is actually bad, refer to the original post for the ACmV specs.

 

[kashgvd]

Thanks clkelley! This fixed the issue on my Z71. Traction control was activating when accelerating.

 

[ludvball]

I have been having similar problems. It started as traction active coming on and loosing power. Then it progressed to the brakes having the weird stopping. The hub on drivers side was replaced about a year ago, and looked good when looking in the sensor hole. The passenger side hub was bad I have replaced the ABS sensor on driver side, and hub assembly on passenger side, which came with a new sensor.

Initially, everything seemed good, other than the ABS light not going out. I figured it just needed to be reset. About a week after changing the hub assembly and sensors, I am now beginning to experience both issues again. I am thinking the next thing to check would be the ABS module? Any help would be appreciated.

 

[electro]

Initially, everything seemed good, other than the ABS light not going out. I figured it just needed to be reset. About a week after changing the hub assembly and sensors, I am now beginning to experience both issues again. I am thinking the next thing to check would be the ABS module? Any help would be appreciated.

I think that would be the next step.

Can you get your truck scanned? A GM dealer can get the codes of there for you and you will know if its the EHCU (Electro-Hydraulic Control Unit).

I'm going to replace mine asap with a used one for around 250. There close to 500 for a new one here in Ontario. I had a whole bunch of codes and so I cleaned the sensors and now I just have a code which I wrote down and cannot find at the moment but it is a defective EHCU.

Good luck.

 

[ludvball]

Can you get your truck scanned? A GM dealer can get the codes of there for you and you will know if its the EHCU (Electro-Hydraulic Control Unit).

I'm going to replace mine asap with a used one for around 250. There close to 500 for a new one here in Ontario. I had a whole bunch of codes and so I cleaned the sensors and now I just have a code which I wrote down and cannot find at the moment but it is a defective EHCU.

Good luck.

A friend of mine has a cheap scanner that i used before I replaced the hub and sensors. It didn't show any codes. So, I will have to go to my fathers shop and check the codes.

Man $500 for the module.