help diagnose

[RidinLow94]

On the knock sensor code issue, they produce their own ac voltage by a crystal inside them that vibrates, (if you already knew that I apologize) so I would look at the wire off each one being it's a signal wire to the pcm. I've also read about the torquing of them being critical when installing, and that it can affect their output. The large voltage drop isssue you are having could definately be ground related, but just to be safe double check all of your connections and look for corrosion of any kind...basically anything to cause a resistance in those circuits. Hope I could be of some help.

thanks, I'll check again

I have replace a lot of these at the dealership. If it just spins then you have to take the valley cove off and turn the outside of the sensor with a pair of channel locks. If it is a 6.0 block then the knock sensor holes are part of the block casting (no inserts). Get the small round gasket for valley cover since you will probably rip it during removal. Over time I have learned it is best to only use gm sensors and usually replace the knock sensor sub harness at the same time.


Picture of knock sensor mounts in the valley. Note: this is a 5.3 block

thanks, this is what I was hoping to hear. My problem is that the sensor is stuck in and the valley cover is still on. I'm gonna try to lift the valley cover up enough to get a pair of vise grips or channel locks on it. Hopefully I can get it loose