For 1990-2009 cars

### Circuit Description

The knock sensor (KS) system monitors the knock sensors in order to determine if detonation is present. If the KS system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal from the KS system. The knock sensor produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

The ECM tests the functionality of the internal knock sensor signal evaluation circuitry. The KS circuitry within the ECM is responsible for receiving, amplifying, filtering, and evaluating the AC voltage and frequency from the knock sensors. The ECM performs two tests that determine if the internal circuitry within the ECM is functioning correctly.

#### Test 1

The ECM internally turns OFF the knock sensor signal circuits. The ECM then applies different test signals to the internal KS circuitry to verify that each test signal output response is within range. If the ECM detects that any of the test signals are not within range, this DTC sets.

#### Test 2

The ECM internally turns OFF the knock sensor signal circuits. The ECM then tests for any output response when no test signals are applied. If the ECM detects an output response, this DTC sets.

#### Test 3

The ECM internally turns OFF the knock sensor signal circuits. The ECM generates an internal test pulse and monitors the return signal. If the return test pulse is less than a calibrated threshold, this DTC sets.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0324 Knock Sensor (KS) Module Performance

### Conditions for Running the DTC

#### Conditions 1

• | The knock sensors control system is active.

• | The change in engine speed per second is less than 2,300 RPM.

• | The change in MAP per second is less than 50-100 kPa.

• | Test pulse signal failure is not set.

• | DTC P0324 runs continuously every 510 engine revolutions, once the above conditions are met for a total 50 seconds.

#### Conditions 2

• | The knock sensors control system is active

• | The engine speed is between 1,000-4,200 RPM and steady.

• | The change in engine speed per second is less than 2,300 RPM.

• | The change in MAP per second is less than 50-100 kPa.

• | Test pulse signal failure is not set.

• | DTC P0324 runs continuously every 510 engine revolutions, once the above conditions are met for a total 50 seconds.

#### Conditions 3

• | Engine Coolant Temperature is greater than 60°C (140°F).

• | The change in engine speed per second is less than 2,300 RPM.

• | The change in engine load is less than 50-100 kPa per second.

• | Test signal failure is not set.

• | DTC P0324 runs continuously every 510 engine revolutions, once the above conditions are met for a total 50 seconds.

### Conditions for Setting the DTC

• | The ECM detects the output response of test signal is less than 500 mV or more than 930 mV, and it occurs 2 times consecutively.

| OR

• | The ECM detects that the output response of test signal changes less than 60-40 V per second, and it occurs 2 times consecutively.

| OR

• | The ECM detects that an internal test pulse signal is less than 3.7 V, and it occurs 2 times consecutively.

• | One of the conditions exists for more than 4 seconds

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of he failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.

• | A current DTC, last test failed, clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | Clear the MIL and the DTC with a scan tool.

### Test Description

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

1. This step determines if a condition exists.

2. A crankshaft sensor DTC could cause this DTC to set.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Important: If you can hear an engine knock, repair the engine mechanical condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical .

1. Observe the Freeze Frame/Failure Records for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure records.

Did the DTC fail this ignition?

Go to Step 3

Go to Intermittent Conditions

3 | Is DTC P0335, P0336, or P0338 also set? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | Go to Step 4
4 | Replace the engine control module (ECM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | --
5 |

1. Clear any DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 6

6 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK