P0325

CIRCUIT DESCRIPTION

The KS system monitors both knock sensors in order to determine if detonation is present. If the KS system determines that excessive knock (detonation) is present, the PCM retards the spark timing based on the signals from the KS system. When knock is present, the KS system voltage input signal to the PCM goes low. The PCM then retards timing until no knock is present. When the KS system is malfunctioning, the KS circuit voltage going to the PCM goes low. The PCM interprets this low signal as spark knock.


CONDITIONS FOR SETTING THE DTC

^ Engine speed is between 1500 RPM and 3500 RPM

^ Engine coolant temperature is greater than 70°C (158°F)

^ TP sensor is greater than 2%

^ Engine operating for longer than 20 seconds

^ A malfunction with the KS system or circuits within the PCM are faulty.


ACTION TAKEN WHEN THE DTC SETS

^ The PCM illuminates the Malfunction Indicator Lamp on the second consecutive drive trip that the diagnostic runs and fails.

^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM turns the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.

^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.

^ A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.

^ The PCM battery voltage is interrupted.

^ Use a scan tool in order to clear the MIL/DTC.


DIAGNOSTIC AIDS

^ If the diagnostic test does not run, review the Conditions for Setting the DTC criteria.

^ For an intermittent condition, refer to Symptoms. Testing and Inspection


TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

2. This DTC indicates an internal PCM problem.