new front whl spd sensors, had scanned yesterday found brake light sw code and RF code due to wire chafe which has been rerouted and taped up. cleared codes, went home and changed 4wal dump valve & module w/known good one yesterday(wouldn't engage manually with Tech2 scan) though I haven't bled system(pedal lower but ok) roadtest, still system doesn't respond? I then threw a new brake light switch in for sh*ts and giggles, still the same but will get another scan hopefully tomorrow. Could it be the PCM? I do have another known good from another 97' 4wal 4.3 but with a manual trans and a/c??? I am getting 12v to the pump.