Circuit Description

Knock Sensor (KS) module is located in PCM. KS module monitors both knock sensors to determine if detonation is present. If excessive knock is present, PCM will retard timing until knock goes away. When KS module is missing or malfunctioning, KS circuit voltage going to PCM will go low. PCM interprets this low signal as spark knock.

Conditions for running DTC are: no AIR, VSS, TP, CKP, MAF or ECT sensor DTCs set, engine speed is 1000-3000 RPM, throttle angle is greater than 15 percent, engine load is greater than 45 percent, coolant temperature is greater than 149°F (65°C), maximum spark retard is less than 15 degrees, system voltage greater than 9 volts, and engine run time is greater than 30 seconds.

DTC will set when PCM detects a malfunction in the integrated knock sensor diagnostic circuitry which will not allow proper diagnosis of knock sensor circuit.