P0332 - Knock Sensor 2 Circuit Low (Bank 2) KEEPS COMING BACK

[Rafael86]

Hi,
I am new to HP Tunners and I bassically purchased this software to be able to install efans on my 99 Chevy Silverado which I already did and everthing has been working great in addition to the AC pressure swich that made is work like the 2005+.

I have have repaced my knock sensors on my truck 3 times already with AC delco products and I did have deffective sensors which i've replaced. This 3rd time I did the replacements I still keep getting the same code and dont know what to do... I've already checked resistence thru the harness and all the way to the blue harness on the computer and the resistence is within the required range.

Any one else knows what could it be?

[RDF1]

So you clear the DTCs and the code comes back instantly?

[TheMechanic]

If you are buying the A/C delco ones on Amazon they are counterfeit. HUGE problem with that right now. ANY time I put them in I use dealer ones. Even dropping the box can damage them. They are also a one time use. They MUST be torqued. After all that you need the new updated pigtail and they need to be RTV sealed around the edges as per the GM bulletin. Before I RTV them I ALWAYS use my oscilloscope on them to verify voltage output with VERY light hammer hits on the block. Do all this and it will be very rare you will need to replace them.

[danmw2003]

Circuit low faults are generally caused by excessive resistance in that circuit. Potentially a bad sensor, a pinched wire in the harness, or spread pins in the connector from probing. Also, aftermarket sensors are generally garbage if that's what you used. Use OEM

[Rafael86]

I clear the DTC every time and then the code comes back after 60+ miles..

[Rafael86]

If you are buying the A/C delco ones on Amazon they are counterfeit. HUGE problem with that right now. ANY time I put them in I use dealer ones. Even dropping the box can damage them. They are also a one time use. They MUST be torqued. After all that you need the new updated pigtail and they need to be RTV sealed around the edges as per the GM bulletin. Before I RTV them I ALWAYS use my oscilloscope on them to verify voltage output with VERY light hammer hits on the block. Do all this and it will be very rare you will need to replace them.

The first time I did purchased from Amazon " AC Delco sensors & Dorman harness" - which one of them did ended up bad. Then the second time I replace the bad sensor with one I bought from AutoZone "AC Delco brand" and did the same thing... then the third time I went to the dealer and purchased both knock sensors and harness thinking this would be the charm and ended up being the same thing - torqued to spec. I know those sensors are good becuase I tested the resistence and they at at 99, tested all the way to the computer pins and they still hold the same resistence, so I know the wiring is good just running out of ideas...
Thanks for your feedback

[5FDP]

I'd just turn the code off.

[TheMechanic]

The first time I did purchased from Amazon " AC Delco sensors & Dorman harness" - which one of them did ended up bad. Then the second time I replace the bad sensor with one I bought from AutoZone "AC Delco brand" and did the same thing... then the third time I went to the dealer and purchased both knock sensors and harness thinking this would be the charm and ended up being the same thing - torqued to spec. I know those sensors are good becuase I tested the resistence and they at at 99, tested all the way to the computer pins and they still hold the same resistence, so I know the wiring is good just running out of ideas...
Thanks for your feedback

Resistance testing is NOT the proper method for testing knock sensors. It can tell you if you have an open or high resistance of a circuit but it can not tell you that a proper resistance measurement means the circuit is good.
As to knock sensors the ONLY test that is accurate and per most manufacturers procedures is to use an oscilloscope. That's it. Nothing else works. You get a nice clear voltage waveform to look at with a O scope. When you see a good one and a bad one it will pay for itself.

[Alvin]

Are you replacing the knock sensor harness too? Torque to spec?

I've had issues mainly 97-98's that I couldn't fix. I think at a certain point the ECM itself is suspect.

[TheMechanic]

I have never had to replace an ECM/PCM because of a knock sensor issue. Every time it has been water/corrosion in the knock buckets of the cover. That is why GM came out with the bulletin to use RTV to seal the seals. Any time the harness isn't pretty much new I will replace it. The plastic connectors are VERY fragile with all of the heat cycles they go through. Like I have said with an O scope the diag is SUPER easy

[RDF1]

I'd just turn the code off.

Same here.
I turn them off all the time.

[Rafael86]

I have never had to replace an ECM/PCM because of a knock sensor issue. Every time it has been water/corrosion in the knock buckets of the cover. That is why GM came out with the bulletin to use RTV to seal the seals. Any time the harness isn't pretty much new I will replace it. The plastic connectors are VERY fragile with all of the heat cycles they go through. Like I have said with an O scope the diag is SUPER easy

I am going to get an oscilloscope and try this out.
Thanks!

[Alvin]

Same here.
I turn them off all the time.

just be careful. sometimes even if the code is turned off the knock sensors will pull max allowable retard if it suspects a problem. You have to zero out the max allowable retard. But then for sure you have no knock sensors.