2009 SWB Sierra 4.3L Knock Sensor

[Uncle Bug]

Hello everyone, having an issue here with the dreaded P0327 knock sensor code. I have put on 2 different AC Delco knock sensors, torqued to spec and the issue still persists. I replaced my spark plugs, coil, and wires, and the issue still persists. I have run chemtool B-12 through the engine and the issue still persists. Does anyone have any helpful tips?

[redvett]

Do a circuit check with a Ohm meter from the sensor to the PCM it probably has an open circuit or bad terminals.

[Ian Mills]

I have a similar, but intermittent issue. I'm interested to hear what you discover

[Uncle Bug]

I checked it with an OHM meter, but to be honest I don’t know what exactly to look for, do I check the sensor? I’m not really sure what I’m looking for

[Grumpy Bear]

3 hours ago, Uncle Bug said:

I checked it with an OHM meter, but to be honest I don’t know what exactly to look for, do I check the sensor? I’m not really sure what I’m looking for

 

Continuity. 

[txab]

It's recommended when replacing KS, replace the wiring harness as well

[Grumpy Bear]

4 minutes ago, txab said:

It's recommended when replacing KS, replace the wiring harness as well

 

Thanks. Did not know that and it makes perfect sense. 

[Uncle Bug]

I have the KS installed on the side of the block, not the ones mounted underneath the intake manifold, which means replacing the harness would require me to disconnect the wire at the ECM and run a whole new wiring harness to the sensor 

[redvett]

13 hours ago, Uncle Bug said:

I checked it with an OHM meter, but to be honest I don’t know what exactly to look for, do I check the sensor? I’m not really sure what I’m looking for

You will need a pinout of the PCM and then check résistance and continuity of the wire from the knock sensor to the PCM and both must be disconnected to test.