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2003 Chevrolet Silverado 6.0L - P0332 Knock Sensor Circuit Low Frequency Intermittent Issue

Model: 2003 silverado 6.0 Fault Code: P0332 Posted: 2015-06-28 19:39

I recently replaced both knock sensors and the associated wire harness due to a persistent P0332 trouble code on my 2003 Chevrolet Silverado 6.0L engine. The #2 knock sensor was severely corroded, so I cleaned it thoroughly, torqued it to 15 ft-lbs, and sealed the boot connections properly. For several weeks, the vehicle ran smoothly without any issues. However, the P0332 code has returned — now showing 'Knock Sensor 2 Circuit Low Frequency' with an intermittent fault indication. I'm wondering if there's another underlying cause or a common failure point I may have missed. Any insights or troubleshooting tips would be greatly appreciated.

Related fault codes

P0332

Comments (2)

Anonymous 2015-06-29 09:28

Did you clear the ECU memory after replacing the sensor? Make sure to use OEM AC DELCO parts, as aftermarket components can cause compatibility issues. Also, check for a faulty alternator diode — it's a known source of intermittent P0332 faults in this model.

Anonymous 2015-06-29 10:35

Hi joe1141, on June 27 I replaced the rear knock sensor on my 2003 Silverado. After completing the repair, I reset the system but the Check Engine light remained on. Here’s what I did to troubleshoot — maybe it helps you. I initially forgot to tighten the gas cap after opening it to depressurize the fuel system during the repair. Some sources indicate that low fuel pressure can trigger a P0332 code. I tested by removing the negative battery terminal — the Check Engine light stayed on, which ruled out a simple power issue. I measured resistance at the waterproof connector end of the 'Y' knock sensor harness and got 1.6k ohms on both pins, confirming a proper connection and no pinching or damage during installation. I also verified the leads were intact before installing the intake manifold. What ultimately resolved the issue was wiping the waterproof connector’s pins and blade contacts with a cotton swab using dielectric silicone compound. The slight scraping action of my multimeter's alligator clip may have also helped improve contact. After resetting the system, the Check Engine light turned off immediately upon startup. I now believe the root cause was likely corrosion on the waterproof connector itself — something that’s easy to overlook. This experience has been very helpful for me and might be useful for others facing similar issues.