For 1990-2009 cars

### Circuit Description

The engine control module (ECM) has the ability to check the functionality of its internal knock sensor (KS) signal evaluation circuitry. This circuitry is responsible for receiving, amplifying, filtering, and evaluating the AC voltage and frequency from knock sensor 1 bank 1 and knock sensor 2 bank 2. The ECM will perform 2 tests that will determine if the internal circuitry is functioning correctly. During the first test, the ECM will internally open each of the wires that connect each knock sensor to the ECM. It will then run 3 different test signals through the circuitry to verify that each test signal output response is within range. If any of the 3 output responses are not within range, an internal knock sensor hardware failure has occurred. During the second test, the ECM will again internally open each of the wires. It will then check for any output response when no test signals have been applied. If an output response is present, then one of the drivers used to open the circuits has failed. An output response could only be caused by a signal from one of the knock sensors. DTC P0324 sets when an internal knock sensor hardware failure has occurred.

### Conditions for Setting the DTC

DTC P0324 will set if the ECM has detected a fault in the internal knock sensor evaluation circuitry when:

• | The engine is running.

• | The engine coolant temperature (ECT) is greater than 40°C (104°F).

DTC P0324 diagnostic runs once every 255 ignition events once the above conditions have been met.

DTC P0324 is a type C DTC.

### Diagnostic Aids

Important: An external knock sensor circuit fault will NOT set this DTC. The ECM internally opens each of the wires that connect each knock sensor to the ECM during the DTC P0324 diagnostic.

Record all ECM DTCs and include with repair information.

Replace the ECM. Refer to DTC P0601 for the reprogramming and learning procedures.