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For 1990-2009 cars only
Makes 🢒 Buick 🢒 1999 🢒 Park Avenue 🢒 Engine 🢒 Engine Controls - 3.8L 🢒 DTC P0327 Knock Sensor (KS) Circuit

Object Number: 405557 Size: SF
Engine Controls Components
OBD II Symbol Description Notice
Cell 20: MAF, IAC and Knock Sensors
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM contains integrated Knock Sensor (KS) diagnostic circuitry. Input signals from the knock sensors are used to detect engine detonation, allowing the PCM to retard Ignition Control (IC) spark timing based on the amplitude and frequency of the KS signal being received. The knock sensors produce an AC signal under all engine operating conditions. During engine operation, the PCM calculates the average voltage of each knock sensor's signal. If the knock sensor system is operating normally, the PCM should monitor KS signal voltages varying over 0.5 volt above and below the calculated average voltage. If the PCM detects a Knock Sensor 1 signal voltage within the calculated average voltage range, DTC P0327 will set.

Conditions for Running the DTC
  1. No TP sensor, VSS, CKP, MAF, or ECT DTCs are set.
  2. VIN K - Engine speed is between 1000 and 4000 rpm.
  3. VIN 1 - Engine speed is between 1000 and 3000 rpm.
  4. VIN K - Throttle angle is greater than 3%.
  5. VIN 1 - Throttle angle is greater than 15%.
  6. VIN K - Engine load is greater than 20%.
  7. VIN 1 - Engine load is greater than 45%.
  8. Engine coolant temperature is greater than 75°C (167°F).
  9. Maximum spark retard is less than 15°.
  10. System voltage is greater than 9 volts.

Conditions for Setting the DTC

The PCM detects a Knock Sensor 1 signal voltage within the calculated average voltage range.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC
    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Check for the following conditions:

    • Poor connection at the PCM or Knock Sensor 1.
        Inspect knock sensor 1 and PCM connectors for backed out terminals, broken locks, and improperly formed or damaged terminals.
    • Misrouted harness.
        Inspect the knock sensor harness to ensure that it is not routed too close to high voltage wires such as spark plug leads.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. Ensures that the malfunction is present.

    2.

  2. If sent here from symptoms, proceed with the diagnostic table.

DTC P0327 - Knock Sensor Circuit

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If a mechanical engine knock can be heard, repair the engine mechanical problem before proceeding with this diagnostic. Refer to Engine Noise Diagnosis .

  1. Operate the engine within conditions specified in Conditions for Setting the DTC.
  2. Using a scan tool, monitor Specific DTC info for DTC P0327 until the DTC P0327 test runs.

Does scan tool indicate DTC P0327 failed this ignition?

--

Go to Step 4

Go to Step 3

3

  1. Turn ON the ignition switch, engine not running.
  2. Review and record scan tool Fail Records data for DTC P0327.
  3. Operate vehicle within Fail Records conditions.
  4. Using a scan tool, monitor Specific DTC info for DTC P0327 until the DTC P0327 test runs.

Does the scan tool indicate DTC P0327 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4
  1. Disconnect the PCM and the Knock Sensor.
  2. Check the KS circuit for opens and shorts to ground.
  3. If a problem is found, repair as necessary. Refer to Wiring Repairs .

Was problem found?

0V

Go to step 7

Go to Step 5

5
  1. Check the KS signal circuit for a poor terminal connection at the knock sensor.
  2. If a problem is found, repair as necessary. Refer to Testing for Continuity , Intermittents and Poor Connections Diagnosis , Repairing Connector Terminals , Connector Repairs .

Was problem found?

--

Go to Step 7

Go to Step 6

6

Replace the knock sensor. Refer to Knock Sensor Replacement

Is action complete?

--

Go to Step 7

--

7
  1. Review and record Fail Records data
  2. Clear DTCs.
  3. Operate the vehicle within Fail Records conditions.
  4. Using a scan tool, monitor Specific DTC info for DTC P0327 until the DTC P0327 test runs.

Does the scan tool indicate DTC P0327 failed this ignition?

--

Go to Step 2

System OK