GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Intrigue 🢒 DTC 🢒 DTC P0327 Knock Sensor Circuit Low Voltage

Object Number: 293677 Size: SF
CKP/CMP/KS (98 W OLDS 3.5L LX5)
Engine Controls Components
OBD II Symbol Description Notice
ESD Notice

Circuit Description

The PCM contains integrated Knock Sensor (KS) diagnostic circuitry. The input signal from the knock sensor is 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 sensor produces an AC signal under all engine operating conditions. During engine operation, the PCM calculates the average voltage range of the knock sensor signal. If the knock sensor system is operating normally, the PCM should monitor the KS signal voltage varying over 0.5 volt above and below the calculated average range. If the PCM detects that the Knock Sensor signal voltage remains within the calculated average voltage range, DTC P0327 will set.

Conditions for Running the DTC
  1. No AIR, VSS, TP, CKP, MAF, or ECT sensor DTCs set.
  2. Engine speed is between 1000 and 3000 rpm.
  3. Throttle angle is greater than 15%.
  4. Engine load is greater than 45%.
  5. Engine coolant temperature is greater than 65°C (149°F).
  6. Maximum spark retard is less than 15 degrees.
  7. System voltage is greater than 9 volts.
  8. Engine run time greater than 30 seconds.

Conditions for Setting the DTC

The PCM detects that the Knock Sensor signal voltage remains within the calculated average voltage range.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

The PCM will use a calculated spark retard value to minimize knock during conditions when knock is likely to occur. The calculated value will vary based on engine speed and load.

Conditions for Clearing the MIL/DTC
    • The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
    • A last test failed (current DTC) clears when the diagnostic runs and does not fail.
    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • Use a scan tool in order to clear the MIL/DTC.
    • Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description , Clearing Diagnostic Trouble Codes.

Diagnostic Aids

Notice: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:

   • The PCM harness connectors
   • The electrical center fuse/relay cavities
   • The component terminals
   • The component harness connector
Using this kit will prevent damage caused by the improper probing of connector terminals.

Reviewing the Failure 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.

If the problem is intermittent, refer to Intermittent Conditions .

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.

    3.

  3. If the problem persists after replacing the sensor, the PCM may be at fault, however, this is an unlikely failure.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn the key to Off, wait 15 seconds.
  2. Operate the engine within conditions specified in Conditions for Running the DTC.
  3. 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 the key to Off, wait 15 seconds, then turn the key to On.
  2. Review and record Failure Records data for DTC P0327.
  3. Operate the vehicle under the same conditions indicated in Fail Records (as closely as possible). The vehicle must also be operating within the conditions required for the diagnostic to run. Refer to Conditions for Running the DTC.
  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

Refer to Diagnostic Aids.

4
  1. Disconnect the PCM and the Knock Sensor.
  2. Check the KS circuit for the following conditions:
    3. • Open circuit
    • Short to ground
    • Short to power
  3. If a problem is found, repair as necessary.

Was a problem found and corrected?

--

Go to step 7

Go to Step 5

5

Check the the KS signal circuit for poor connections/terminal tension at the Knock Sensor and at the PCM. Refer to Intermittents and Poor Connections Diagnosis .

Was a problem found and corrected?

--

Go to Step 7

Go to Step 6

6

Replace the Knock Sensor. Refer to Knock Sensor Replacement .

Is the action complete?

--

Go to Step 7

--

7
  1. Clear DTCs with the scan tool.
  2. Turn the key to Off and wait 15 seconds
  3. Operate vehicle within the conditions that are required for this diagnostic to run. Refer to Conditions for Running the DTC.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 8

Go to Step 2

8

Review Captured Info using the scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to the applicable DTC table

System OK