Hello all,
I've been fighting the C1230 code for a few months now on my 03 2WD Heritage. I searched and read just about every post containing anything resembling my problem but found nothing. I've replaced the rear sensor twice and had a friend of mine clear the codes but the code persists.

My current sensor reads about 1.8K ohms and I'm getting around 3.8vdc from the sensor harness. I'm at my wits end with it and with winter coming I'd like to have the ABS available. Any help would be greatly appreciated.

 

Do you know what the voltage should be, or is that correct? Before I saw where you posted your readings, wiring was the first thing that popped into my head. If you dont know what the proper values should be, I would check the voltage on one of your front sensors should be close. Due to the wire run you would probably see a slightly higher ohm reading in the rear than the front

Have you re-geared or drastically changed tire size, I guess its possible that could cause issues too?