No need to point the blame. First, if you had your FRONT brake pads replaced, and during replacement, if damage was caused to the abs system, you would have had a warning light the first time you applied the brakes, NOT 100 miles later.
Your mechanics replaced the rear abs sensors, yet never replaced the rear brakes?
Where did the brake pedal switch come in?
Now, 2months later, you are asking for advice, since your mechanics must not have the ability to pull codes?
Btw, your crunching is coming from an ABS STOP, caused by a variation of speed between all 4 wheels on the ground.
Coincidence, that your abs light came on after driving 100miles since brake pad replacement, most likely.
Until I have the code and diagnose the cause, then we can come to a conclusion if the issue can be related to front brake pad replacement.
I've been through numerous scenarios over the years. I've had customers try and point blame on my shop for causing an issue to their car. 1 as crazy as trying to blame us for a CEL on, yet she only had the wiper blades replaced.
However, I have also found, a few instances over many years, that could have been caused by the repairs completed.
Main thing right now is to get the code and get it repaired, then you can figure out if the repair could have been caused by your mechanics replacing the front brake pads.
Post the code(s) when you get them.

 

It did happen immediately, meaning the crunching of the brakes as well as the ABS sensor and the dashboard going off like a pinball machine.

The rear brakes were done, by them, in late 2017.

No confirmation why they checked the brake pedal switch, but guessing as they tried to trouble shoot the issue they can't duplicate.

The front pads were done early June, immediately upon pick up it crunched, etc.

The trip was from LA to Disney.

Then from Disney to Palm Springs. It was during that drive that the H3 felt like it was bouncing around, pulled over to a gas station and the tires had been pumped to 45 PSI (should be 35). Let some air out and continued to my destination. Once back, they checked it and said it was fixed. Did not cite what the issue was.

Problem was back, brought it back, they said all is fine now.

This last time out, they replaced the ABS sensors in the hopes that was the issue.

So, out of concern that the brakes might lock up (as you cited the crunching), hoping to get this scanner in hand today before it is driven again.

Thanks again for your help.

 

More information, that's great.
As far as brakes locking up from an ABS failure, it won't happen, eventually the ABS will be disabled.

 

this is the reading I got.

After this drove it around the block 3x without any issues.

Going to do another test after this post.

 

Tested again in the hope I could duplicate the issue, but to no avail.

So, for the night, this is the code C0045

 

When was the last time you replaced the rear differential fluid?

 

Btw, you may need to pull the sensor and clean that too. GL


I tried to pull my dsr oem sensor last year and it broke, however you stated that the rears sensors are new.
https://www.hummerforums.com/forum/h...acement-40365/

 

Vehicle is regularly serviced, so will have to go back and look at my invoices.

 

So is that the issue?

They stated the sensors are new and got them from GM directly. Stated it was under warranty.

 

You have an intermittent issue that could be caused by debris floating around in the rear axle, causing a signal loss to the LEFT REAR sensor. Start by changing the fluid!
Sorry, as this could not be caused by front brake pad replacement.