Diagnosis
The PCM calculates an average voltage the KS signal and takes instantaneous signal voltage readings. The PCM uses the instantaneous signal voltage reading to determine the state of the KS circuitry. If the KS system is operating normally, the PCM should monitor instantaneous KS signal voltage readings varying outside a voltage range above and below the calculated average voltage. The following Diagnostic Trouble Codes (DTCs) are used to diagnose the KS system:^ If the PCM malfunctions in a manner which will not allow proper diagnosis of the KS circuits, DTC P0325 will set.
^ DTC P0327 is designed to diagnose the KS, and related wiring, so problems encountered with the KS system should set a DTC. However, if no DTC was set but the KS system is suspect because detonation was the customer's complaint, use the tables for DTC P0327 to diagnose the Detonation/Spark Knock Symptom.