July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Code 43, Knock Sensor Without Spark Module (Dual Sensors): Notes

WARNING: This page is about a different car, the 1995 GMC Sonoma and 1995 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Test numbers refer to test numbers on diagnostic chart.

Tests for 5-volt signal applied by control module.
An improperly installed sensor can prevent knock sensor from grounding to block.