Diagnostic Aids
Check knock sensor signal circuit for a potential open or short to ground. An open knock signal circuit would cause 5-volt reference to remain high at PCM knock signal terminal. A short to ground in knock sensor signal circuit would cause 5-volt reference signal to pull low to near zero volts. If either of these conditions exists for about 10 seconds, a Code 43 will set. Resistance to ground through sensor should be 3300-4500 ohms.
When attempting to diagnose an intermittent problem, use scan tester to review supplemental diagnostic information. Supplemental data (scan tester MALF HISTORY) can be used to help duplicate an intermittent problem. Using Diagnostic Service Probe (12092782) allows voltage to be read on wires without disconnecting connectors. Resistance to ground through sensor should be 3300-4500 ohms. A loose sensor could set code. Sensor torque is 133 INCH lbs.