Knock Sensor: Testing and Inspection

SCAN TOOL DIAGNOSIS
The Tech 1 scanner (or equivalent) has several positions for diagnosing the Knock Sensor (KS) circuit. "Knock signal" is used to monitor the input signal from the knock sensor. This position should display "YES" to indicate when a knock is being detected. "Knock retard" is the indication of how much the Powertrain Control Module (PCM) is retarding the spark.

Diagnostic Trouble Code (DTC) 43 is designed to diagnose the knock sensor circuit. Problems encountered with this circuit should set DTC 43. However, if no DTC 43 was set but the KS system is suspected, refer to System Diagnosis/Diagnostic Charts/C Charts/Chart C-5. Chart C-5 Knock Sensor (KS) System Check