Circuit Description
The knock sensor (KS) diagnostic circuitry is contained within the powertrain control module (PCM). The KS produces an AC voltage at all engine speeds and at loads. The PCM adjusts spark timing that is based on the amplitude and on the frequency of the KS signal. The PCM uses the KS signal to calculate the average voltage. Then the PCM assigns a voltage value. The PCM inspects the KS and related wiring by comparing the actual knock signal to the assigned voltage range. A normal KS signal should stay outside the assigned voltage range. This DTC will set if the KS signal is within the assigned voltage range, or if the KS signal is not present . DTC P0327 refers to the bank 1 KS, and DTC P0332 refers to bank 2 KS.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0327 Knock Sensor (KS) Circuit Bank 1 |
| • | DTC P0332 Knock Sensor (KS) Circuit Bank 2 |
Conditions for Running the DTC
| • | DTC P0101, P0102, P0103, P0116, P0117, P0118, P0121, P0122, P0123, P0125 if applicable, P0335, P0336, P0340, P0341, P0385, P0386, P0502, or P0503 is not set. |
| • | The engine speed is between 1,000-2,500 RPM. |
| • | The engine has been running for a minimum of 30 seconds. |
| • | The throttle angle is more than 10 percent. |
| • | The engine load is more than 40 percent. |
| • | The engine coolant temperature (ECT) is more than 60°C (140°F). |
| • | The maximum spark retard is less than 15 degrees. |
| • | The system voltage is more than 9 volts. |
| • | The diagnostics run continuously when the above conditions are met. |
Conditions for Setting the DTC
The PCM detects a KS signal voltage within the predetermined average voltage range for at least 2 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 the 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 3 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 number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool display any other DTCs set? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 |
|
Important: If a mechanical engine knock can be heard, repair the engine mechanical condition before continuing with this diagnostic test.
Did the DTC set? | -- | Go to Step 4 | Go to Intermittent Conditions | |
4 |
Is the resistance of the KS near the specified range? | 100K ohms | Go to Step 5 | Go to Step 9 |
5 |
Important: DO NOT tap on plastic engine components. Is any signal indicated on the DMM while tapping on the engine block near the KS? | -- | Go to Step 6 | Go to Step 9 |
6 |
Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 |
7 |
Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 8 |
8 |
Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
9 | Replace the affected KS. Refer to Knock Sensor 1 Replacement or Knock Sensor 2 Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 12 |
12 | 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 in Vehicle DTC Information | System OK |
