GM Service Manual Online
For 1990-2009 cars only

Object Number: 210769  Size: SF
Engine Controls Components
Cell 20: Engine Controls - PCM EVAP and EGR Control
OBD II Symbol Description 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. The PCM calculates an average voltage of each knock sensor's signal and takes instantaneous signal voltage readings. The PCM uses the instantaneous signal voltage readings to determine the state of the knock sensor circuitry. If the knock sensor system is operating normally, the PCM should monitor instantaneous KS signal voltage readings varying outside a voltage range above and below the calculated average voltage. If PCM detects a Knock Sensor 2 signal voltage within the calculated average voltage range, DTC P0332 will set. Refer to Knock Sensor (KS) System Description for further information.

Conditions for Running the DTC

    • No TP sensor, VSS, CKP, MAF, or ECT DTCs are set.
    • VIN K - Engine speed is between 1000 and 4000 rpm.
    • VIN 1 - Engine speed is between 1000 and 3000 rpm.
    • VIN K - Throttle angle is greater than 3%.
    • VIN 1 - Throttle angle is greater than 15%.
    • VIN K - Engine load is greater than 20%.
    • VIN 1 - Engine load is greater than 45%.

Conditions for Setting the DTC

The PCM detects a Knock Sensor 2 signal voltage within the calculated average range.

Action Taken When the DTC Sets

    • The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.
    • 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

    • A history DTC P0332 will clear after 40 consecutive warm-up cycles have occurred without a fault.
    • DTC P0332 can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for the following conditions:

    • Poor connection at the PCM or Knock Sensor 2.
        Inspect knock sensor 2 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. If sent here from symptoms, proceed with the diagnostic table.

DTC P0332 - Knock Sensor 2 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 P0332 until the DTC P0332 test runs.

Does scan tool indicate DTC P0332 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 P0332.
  3. Operate vehicle within Fail Records conditions.
  4. Monitor Specific DTC info for DTC P0332 until the DTC P0332 test runs, using a scan tool.

Does the scan tool indicate DTC P0332 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4

  1. Disconnect the PCM and bank 2 knock sensor (KS).
  2. Check the bank 2 knock sensor circuit for opens and shorts to ground.
  3. If a problem is found, repair as necessary. Refer to Wiring Repairs .

Was problem found?

--

Go to step 7

Go to Step 5

5

  1. Check the bank 2 KS signal circuit for a poor terminal connection at the knock sensor.
  2. If a problem is found, repair as necessary. Refer to Wiring Repairs .

Was problem found?

--

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. Review and record Fail Records data
  2. Clear the DTCs.
  3. Operate the vehicle within Fail Records conditions.
  4. Monitor Specific DTC info for DTC P0332 until the DTC P0332 test runs, using a scan tool.

Does the scan tool indicate DTC P0332 failed this ign?

--

Go to Step 2

System OK