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Tool Hut
Tool Hut, ASE Certified Technician
Category: Chevy
Satisfied Customers: 494
Experience:  Owner of a mobile diagnostics company assisting auto technicians with difficult vehicles
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I have a 2005 Silverado and have a persistent knock sensor

Customer Question

I have a 2005 Silverado and have a persistent knock sensor (bank 2) code, I have replaced the sensors and wires twice and the code still persists after about a day of driving, also the engine only has 4k miles the fuel pump is also new along with sensors and wires I cannot fix this issue what is the problem that I am not seeing?
Submitted: 1 year ago.
Category: Chevy
Expert:  Tool Hut replied 1 year ago.

Hi, My Name is***** have over 20 years experience repairing vehicles. I am a ASE Certified Master Auto Technician. I am confident we can resolve your problem together.Please remember I don't know your skill level. I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies to get to a satisfactory resolution.I also try to give all of the information you may need expecting a positive rating. If there is any reason I cannot get a positive rating please let me know.

Do you a scanner that can view the knock sensor data?

Customer: replied 1 year ago.
I do not have a scanner that can display the data of the sensor just one that tells me the sensor has a low voltage imput
Expert:  Tool Hut replied 1 year ago.

What is the code number?

Customer: replied 1 year ago.
P0332
Expert:  Tool Hut replied 1 year ago.

Have you torqued these sensor or just put them in? They need to be torqued to 15 lbft. a loose or tight sensor can cause this code.

Customer: replied 1 year ago.
I torqued them to spec.
Expert:  Tool Hut replied 1 year ago.

The best way to verify is with a scanner. There are only a few suspects on this system.

  • Engine Noise
  • Poor connection
  • Improper installation
  • Bad sensor
  • Bad PCM
Customer: replied 1 year ago.
The engine is quiet, the harness is new, the sensors are new, they were installed to the manual and torqued to spec. The only thing I have not done is change the PCM, but I have no other symptoms of a failing PCM
Expert:  Tool Hut replied 1 year ago.

The PCM may have only the one symptom. The best way to verify is with a scanner and a volt meter.

Customer: replied 1 year ago.
Ok, what is the normal operating voltage range for the knock sensors? And also how else can I determine PCM failure with no symptoms or PCM codes?
Expert:  Tool Hut replied 1 year ago.

What brand are the knock sensors? I am looking for a test procedure for you and see a huge problem with the aftermarket sensors. I only use Delco and have had a defective ones before.

Expert:  Tool Hut replied 1 year ago.

There is a GM bulletin on these. replacing the sensors and harness. Send me your VIN and I can tell you if there was a calibration change for the PCM to address this

Customer: replied 1 year ago.
I used ac delco, VIN 1GCEK19Z65Z245993
Expert:  Tool Hut replied 1 year ago.

There is not an update for the PCM for this problem. It does have an update for an O2 code.

The resistance of the knock sensor should be 93K-107K ohm with key off.

To test place the meter in the 400 mv AC HZ scale. tap engine near sensor and observe readings.

The PCM monitors the AC HZ transmitted by the sensors.

You can check at the PCM Sensor 2 is a lt blu wire in Connector 1 pin 17

Expert:  Tool Hut replied 1 year ago.

If the PCM is getting the reading then I would suspect PCM

Customer: replied 1 year ago.
the PCM should not get a reading with the engine off? While it is getting a voltage imput? If the voltage imput is still low with the engine off then would it be a faulty sensor? Also I am not getting an 02 code on the scanner, what exactly should I be looking for on the O2 code
Expert:  Tool Hut replied 1 year ago.

The PCM Should not get a reading with the engine off. The O2 update is for a PCM calibration update. Since you are not having this concern I would not get the update yet. I just wanted you to be aware that there is a possible calibration update for your PCM.

Expert:  Tool Hut replied 1 year ago.

It has been a couple of days since I have heard from you. Do you still need assistance? I have also noticed that I have not received a rating from you. If for some reason you question did not get answered please reply. I am only compensated for my time when you leave a positive rating. Your understanding is appreciated.