Do you live where rust is a big deal? While a slightly different setup, my S10 blazer's front wheel speed sensor mounting pad rusted up, lifting the sensor away from the tone ring and caused the ABS to activate whenever you touched the brakes. I'm not sure about the Nissan, but you could check the Chevy with a multimeter set to VAC, at the sensor side plug, spinning the wheel and comparing side to side IIRC.Update: The ABS activates every time I touch the brake pedal now. The ABS light is FINALLY on! Now I have a place to start troubleshooting.
Fun Fact for ABS light troubleshooting, with your vehicle off, on your OBD2 port under your steering console, if you jump the top right terminal (#9) to the 4th from the right terminal on the bottom row (#4), then turn the ignition on, the ABS light will flash you the error code(s). The long dashes represent 10's, and the short dashes represent 1's.
In my case I got 2 long dashes, and 5 short dashes....code 25 which refers to "Front Left Sensor" error.
I've called auto parts stores and the going rate is over $100 ! My service manual has some troubleshooting steps that I can exhaust before handing over all that money. I'll provide an update. Once I know more. If anyone has any experience with this type of ABS code, I'd be glad to hear about it!