I don't know the voltage I'm getting. I'll have to check. Any idea what the voltage is supposed to be?
No voltage output from a knock sensor unless you induce a vibration (hit your block with a hammer-tap it). You will only see AC voltage proportional to the amplitude of the induce strike. Typically on the bench vice you will see from 20 - 110 mv on a meter best to view on an oscope if you have one.
Couple of things:
Consider mounting the sensor externally until it proves 100%. There is a mounting hole on the left front side of the block near the water pump. Use a crimp ferrel female connector to connect to the sensor stud; then cut the original sensor wire from the in line connector (allow 4” or so to splice your new wire in place of the original sensor.
Clean the new mounting hole with a tap or bolt, then clean it with brake cleaner fluid. The threads are the connection to ground, dirty threads are likely your issue with the replacement sensors, either that or they are not sensitive enough (use GM certified sensors if you can).
The PCM connection could be corroded check to see if they are clean. I initially swapped my bad bank 1 sensor with a 100K ohm resistor and error code went away for a while (bank 1 was shorted to ground internally) eventually the PCM flagged it b/c of the lack of a signal (back to the sensitivity issue); I swapped the resistor to bank 2 and put bank 2 on bank 1 (at the connector) as I wanted to verify the PCM wiring and operation. Sure enough in a couple of weeks bank 2 was flagged by the PCM; I had my answers- PCM good, wiring good, sensor 1 bad, sensor 2 good. That’s when I decided to change sensor 1 and mount it externally.
Running 3 weeks now w/0 any faults; I might just leave it as is.
Hope this helps.
