2003 Hummer H2 - ABS and TC Warning Light Comes On, Can't Lock Wheels with Differential while Lights are On, and Disturbing Noises

Question

At the moment of startup, there are no issues that are happening when the engine just started running. When I start driving, I hear a subtle squeak noise that seems to be coming from the front wheel driver side. After thirty seconds of driving, the ABS and TC warning lights come on and stay on while the vehicle is running. Also at that time, the noise from the front driver side wheel turns into a grinding sound.

The sound isn't constant, it seems to be happening at every interval of time as if it's caused on every rotation of a turning part. The sound will happen more rapidly depending on speed. At 30 mph, the sound will happen at around 120 times per minute.

A minute later the sound will turn into loud crunching or as if something is being ripped apart.

Whenever I pull over and stop for a moment and start driving again, the sounds start back to squeaking again and would progressively turn into the grinding and crunching sounds as well.

When Googling about these warning lights, it seems that the most likely issue is a faulty wheel speed sensor, which may be likely but I also seem to have a problem with the differential as well because another thing I found out is that I can't lock the axles with the differential. This would only happen after I get the warning lights, it will work before the warning lights come on. It also occurs to me that the sounds may be coming from the middle (where the front differential is) but I just hear it coming out the wheel well.

When reading some other posts on Google, some have said that their ABS would work erratically and will try to brake on one of the wheels; this hasn't been the case for me although I think it may have been trying to work from what it sounds like.

I also took out the fuse for the ABS, ran the vehicle, and the same warning lights came on, no other lights came on. I did not test drive any longer to see if I get the same sounds however unfortunately. When I put the fuse back in and ran the vehicle, I got the same results as well.

While I was driving, I didn't seem to have any problems that would've made it harder for me to drive. I was only driving on 35 mph roads however. I only saw warning lights and heard loud worrisome noises as well as strong vibrations associated with those noises.

Thank you for your help everyone.

Answer 1

From your description, I'd suggest you need to check (or have checked) the wheel bearing on that side. The code you're describing sounds like there's a misalignment of the wheel speed sensor to the tone ring. If a wheel bearing isn't functioning properly, it can throw the hall effect sensor out of alignment with the tone ring which will give a faulty signal. The computer takes into account all of the wheel speed sensors, then if it sees one of them which is not responding as expecting (within parameters), it will throw the code(s). Considering your not getting this until you start moving, usually means the sensor is responding to the computer (no short/open), but it's not feeding the computer the right information. When a wheel bearing goes bad, it can throw this alignment out of whack, which will cause the codes to pop.

The fact you've got noise there, plus you're getting the code(s), leads me to believe the wheel bearing may be at fault.