i first got this code after installing the 3.73 gears last week. i figured it may have been due to the PCM seeing a different vehicle speed than the BCM was seeing since the PCM program was still set-up for 3.23 gear ratio. this difference was ~10MPH @ 70 MPH. but today i got my LT1 Edit up and running and corrected the ratio in the PCM. but the code is still setting.
according to my scanner hooked up in ABS mode, the front and rear wheels are all seeing the same speed and that speed is the same as the "vehicle speed" in the BCM.
after clearing the code, the supply voltage to the BCM is at ~13.6 and stays there through the first few hundred yards then drops to 2.4 volts and the "ABS INOP" light comes on. this is not at any particular speed that i can tell nor any particular time frame, although it is always within the first 45 seconds or so.
once the supply voltage drops to 2.4, it will not change until the key is cycled 'off then on' at which time the code will clear and supply voltage returns to ~13.6.
the ABS fuses check good as does every fuse on the vehicle.
any suggestions?