Knock Sensor: Testing and Inspection

RESULTS OF INCORRECT KNOCK SENSOR (KS) SYSTEM OPERATION
Loss of the KS signal or loss of ground at KS module would cause the signal to the ECM to remain high. This condition would cause the ECM to control IC, as if no spark knocking were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions.

Loss of the KS signal to the ECM would cause the ECM to constantly retard IC. This could result in sluggish performance and cause a DTC 43 to set.

A "Scan tool" will read KC signal in A/D counts. When detonation is detected, KC signal counts will increment, as long as knock is present. "Scan tools" will indicate knock being present either by showing A/D counts, or displaying "Yes" (knock present), or "No" (knock not present). If DTC 43 is present, use that chart to diagnose system. If no DTC is present and KS system is suspected, use CHART C-5. Testing and Inspection