I own a 2004 GMC K1500 with a 5.3L engine and am currently experiencing fault code P0332. The knock sensor is not producing any voltage signal—only showing 5V at the sensor terminal. I've confirmed that there's no power or signal being sent to the knock sensor, which is causing the check engine light to illuminate. I'm looking for advice on how to diagnose and resolve this issue.
yes the connector above the intake before it goes into the wire harness
Many knock sensors are voltage-generating devices and don't require external power—this means they rely on engine conditions to produce a signal. If your 2004 GMC K1500 is throwing a P0332 code, the issue could stem from a damaged wiring harness, water ingress (especially after engine shampoo), or a failed sensor. This failure is relatively common in this model. Some technical service bulletins (TSBs) address these issues—checking online resources like Alldata or manufacturer TSBs may provide solutions.
Thanks for the helpful insight. I'm now planning to replace both the knock sensors and the wiring harness, as they are located beneath the intake plenum. This should resolve the P0332 code and restore proper engine performance.
Have you checked the wiring route beneath the intake manifold? Corrosion or damage in that area could be causing a loss of signal.