Would need someone with an IQ of greater than two to explain this to me. When any idiot or even a kid can buy and install any brake part from any store and improperly install with with no restrains whatsoever. Ha, I was buying brake parts when I was ten years old.
If you read any owners manual, states don't worry if your ABS will still have normal service brakes. But they don't seem to mention if your ABS module has a shorted transistor or corroded solenoid valve, you won't have any brakes to that particular wheel at all. In theory at least, ABS is a secondary system.
But then if you read all this literature on affordable scanners, they state, due to liability reasons, we do not offer the reading of ABS codes. So need to raise at least 4,000 bucks to buy one.
Now its law to have ABS, wish my congressman was with me this morning that passed this law. Had an ice rain last night, if I hit the brakes hard enough, all four wheels would lock up. No differential signal from the two opposite wheels, ABS didn't even come on. Had to leave before the salt truck drivers woke up, but again, sure wish I had studded snow tires on my car that were outlawed a long time ago.
All that scanner tells you is which wheel is bad, but still a long ride from that ABS module to that wheel sensor. Even found a problem in the ABS module itself due to a poorly soldered I/O connector. Yeah, was a label on it, do not open, no user serviceable parts on the inside. But feel the major reason of that label is they didn't want you to see the cheap crap on the inside they were charging a fortune for.
If your ABS is not working, even if some idiot hits you, his insurance company wouldn't be liable because your vehicle has a fault in it. Tell me I am not being truthful in this response.