GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 LeSabre 🢒 DTC 🢒 DTC P0327 or P0332

Circuit Description

The knock sensors (KS) produce an AC signal under all engine operating conditions. The powertrain control module (PCM) calculates the average voltage range of each KS signal. If the KS system is operating normally, the PCM should monitor the KS voltage varying above and below a calculated average voltage. If the PCM detects a KS 1 signal voltage or a KS 2 voltage signal within the calculated average voltage range, a DTC will be set. A DTC P0327 refers to the bank 1 knock sensor. A DTC P0332 refers to the bank 2 knock sensor.

Conditions for Running the DTC
    • DTCs P0101, P0102, P0103, P0117, P0118, P0121, P0122, P0123, P0125, P0336, P0341, P0502, P0503, P1114, P1115, or P1121 are not set.
    • The engine speed is between 1000-2500 RPM.
    • 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 engine run time is more than 30 seconds.

Conditions for Setting the DTC

The PCM detects a knock sensor 1 or knock sensor 2 voltage within the calculated average voltage range.

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.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: If a mechanical engine knock can be heard, repair the engine mechanical condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical in Engine Mechanical.

  1. Observe the Freeze Frame and Failure Records data 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 as specified in the supporting text or as close to the Freeze Frame and Failure Records data that you observed.

Does the DTC fail this ignition?

--

Go to Step 3

Go to Intermittent Conditions

3
  1. Turn OFF the ignition.
  2. Disconnect the appropriate knock sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage of the appropriate signal circuit of the KS harness connector to a good ground.

Does the voltage measure near the specified value ?

0 V

Go to Step 5

Go to Step 4

4

Repair the short to voltage in the KS signal circuit .

Did you complete the repair?

--

Go to Step 9

--

5
  1. Turn OFF the ignition.
  2. Disconnect the PCM and the appropriate knock sensor.
  3. Check the KS circuit for an open or short to ground.
  4. If a condition is found , repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 6

6
  1. Check the appropriate KS signal circuit for a poor terminal connection at the knock sensor.
  2. If a condition is found , repair as necessary. Refer to the following procedures in Wiring Systems:

Did you find and correct the condition?

--

Go to Step 9

Go to Step 7

7
  1. Check the appropriate KS signal circuit for a poor terminal connection at the PCM.
  2. If a condition is found , repair as necessary. Refer to the following procedures in Wiring Systems:

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Replace the knock sensor. Refer to Knock Sensor 1 Replacement or Knock Sensor 2 Replacement .

Did you complete the replacement?

--

Go to Step 9

--

9
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 10

Go to Step 2

10

With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK