Code P0332 P0327 - Knock Sensor or PCM

JASONSTYBA

MEMBER
2001 CHEVROLET SUBURBAN
6.0L
V8
4WD
AUTOMATIC
145,000 MILES

I'm getting codes P0332 & P0327 - Knock Sensor both banks simultaneously even after changing out both sensors with OEM sensors and new wiring harness. I torqued the sensors to 15 Ft. Lbs and cleaned the wells before installation. I've done this twice (once with non-OEM knock sensors) and one with AC-Delco sensors. I checked the wiring to the PCM and it has proper conductivity. I register 101k ohms on both sensors. The wires from both sensors to the PCM seem to be snug and getting connection from the sensors. I'm at a loss what to do next. I've taken the intake off twice and don't want to do it again.

Here's a site I referenced: https://www.obd-codes.com/p0332

I have a bluetooth ODBII reader and after clearing the codes they keep coming back like the image attached shows.

A co-worker suggested changing the PCM. I've never done that. If so, where to get one? Is there something else I should check before buying a PCM replacement? Thanks!

4 Replies

JASONSTYBA

MEMBER
3 POSTS

I found some troubleshooting steps for those codes as well as considering the PCM. The only thing I haven't been able to verify is if the knock sensors produce AC Voltage on the 400mV scale when knocked nearby. I don't have a multi-meter available yet that can show readings at that range. If I can get one, and verify the new sensors are putting out voltage when knocked nearby, signs point to replacing the PCM.

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Saturday, May 4th, 2019 AT 4:30 PM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Gello.

Yes, you are correct that this Direct Trouble Codes (DTC)(s) are for the front and rear Knock Sensors (KS)(s). In the diagrams down below I have included the Diagnostic Troubleshooting Flowcharts from Chevrolet on these DTC's. Please go through these flowcharts and you will definitively have the cause of your vehicle's problem. Please get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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Sunday, May 5th, 2019 AT 11:21 AM

JASONSTYBA

MEMBER
3 POSTS

I followed the steps and got to #13 which says replace PCM. On step #4 I got over 20mV AC when tapping on the engine block for both sensors. Step #5 had little to no resistance (as well as no short to ground nor to voltage) between the harness connector for the knock sensors and the PCM plug (Blue #11 & #51) where they connect. I guess I'll get a replacement PCM.

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Sunday, May 5th, 2019 AT 3:38 PM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello again,

If that's what the flowchart comes up with. It is from Chevrolet and what the factory trained technicians would use to diagnose the problem.

Thanks,
Alex
2CarPros

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Monday, May 6th, 2019 AT 2:34 AM