Good Evening all!!
I have a 5.3 and have a issues with the dreaded knock Sensors i have replaced them 5 times now and i used acdelco and also replaced the harness. yes i also torqued them down to 15 in/lbs i keep geeting p0327 and p0332 the 4th time i only got the p0327 and so i changed just that one the 5th time but still have the p0327 any ideas

 

Water gets down in there. You need to seal it up with RTV sealer, and to hell with what Chevy says about that. The 5.3 ain't a bad motor but that was a lousy design IMO. Don't use ANY pressurized water at a car wash on the intake area as well. Also, parts like these are made in MX or Asia and not to be trusted.I water-proofed my old Jeep, so I know what I am speaking of. Use the RTV sealer ALL the way around that motor.

 

I did Use our RTV sealer I used Quite a bit each time LMAO I am just at a loss at this point I’m not sure why it will not tack them. Maybe ecu issue??

 

Could be that or wires that are bad.

 

i put it in the shop and even they have no idea sensors are testing good and wiring from the sensors to the ecm are good?? truck is done

 

Have you figured your issue out? I've recently replaced mine and have done testing of wires and still get p0237. Thinking PCM maybe

 

its a circuit low code...meausre the harness for a short to grd...it should show no continuity.
if that tests good....disconnect the harness from the knock sensor...yu should get the circuit hight code....if you don't probably ecm. the fault can only be sensor, wires or ecm.

rule out sensor by replacing
rule out wires by ohm check and voltage drop test
if that test good you replace ecm as that can't be tested.

 

Okay I've checked the ohms at 100k each from the harness connection and ground on the alternator. I've checked continuity from ecm to the harness and that's good. What is the voltage drop test?