SFI SYSTEM, Diagnostic DTC:P0327, P0328

DTC Code DTC Name
P0327 Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
P0328 Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

DESCRIPTION

A flat type knock sensor is used. Flat type knock sensors (non-resonant type) have a structure that can detect vibrations over a wide band of frequencies: between approximately 6 kHz and 15 kHz.

Knock sensors are fitted onto the engine block to detect engine knocking.

The knock sensor contains a piezoelectric element which generates a voltage when it becomes deformed.

The voltage is generated when the engine block vibrates due to knocking. The occurrence of engine knocking can be suppressed by delaying the ignition timing.

DTC No. DTC Detection Condition Trouble Area
P0327

Output voltage of knock sensor 0.5 V or less for 1 second or more

(1 trip detection logic)

  • Short in knock sensor circuit

  • Knock sensor

  • ECM
P0328

Output voltage of knock sensor 4.5 V or more for 1 second or more

(1 trip detection logic)

  • Open in knock sensor circuit

  • Knock sensor

  • ECM

Tech Tips

When either DTC P0327 or P0328 is set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is delayed to its maximum retardation. Fail-safe mode continues until the ignition switch is turned off.

Reference: Inspection using an oscilloscope

A005LLDE03
*a 1 V/DIV.
*b 1 ms./DIV.

The correct waveform is as shown.

ECM Terminal Name Between KNK1 and EKNK
Tester Range 1 V/DIV., 1 ms./DIV.
Condition Engine speed maintained at 4000 rpm after warming up engine

MONITOR DESCRIPTION

The knock sensor, located on the cylinder block, detects spark knock. When spark knock occurs, the piezoelectric element of the sensor vibrates. When the ECM detects a voltage in this frequency range, it retards the ignition timing to suppress the spark knock.

The ECM also senses background engine noise with the knock sensor and uses this noise to check for faults in the sensor. If the knock sensor signal level is too low for more than 10 seconds, or if the knock sensor output voltage is outside the normal range, the ECM interprets this as a fault in the knock sensor and stores a DTC.

CONFIRMATION DRIVING PATTERN


  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the intelligent tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

  4. Turn the ignition switch off and wait for at least 30 seconds.

  5. Turn the ignition switch to ON and turn the intelligent tester on.

  6. Start the engine and wait 5 minutes.

  7. Enter the following menus: Powertrain / Engine and ECT / DTC.

  8. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  10. Input the DTC: P0327 or P0328.

  11. Check the DTC judgment result.

    Intelligent tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    UNKNOWN

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or UNKNOWN, idle the engine for 5 minutes and check the DTC judgment result again.

WIRING DIAGRAM

A005HF9E17
*a KNOCK SENSOR
*b (Shielded)

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (KNOCK FEEDBACK VALUE)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the tester on.

    4. Warm up the engine.

    5. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Knock Feedback Value.

    6. Read the value while driving the vehicle.

      OK
      The value changes.

      Tech Tips

      Malfunction does not occur Knock Feedback Value changes
      Malfunction occurs Knock Feedback Value does not change

      The knock feedback value change can be confirmed by running the engine with a high load, for example, by activating the air conditioning system and racing the engine.


    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  2. INSPECT ECM (KNK1 VOLTAGE)


    1. A005IQHE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Knock Sensor)

      Disconnect the knock sensor connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      R1-2 - R1-1 Ignition switch ON 4.5 to 5.5 V

    4. Reconnect the knock sensor connector.


    NG

    CHECK HARNESS AND CONNECTOR (ECM - KNOCK SENSOR) Click here

    OK

  3. INSPECT KNOCK SENSOR


    1. A005HWME26
      Text in Illustration
      *1 Ohmmeter
      *a

      Component without harness connected

      (Knock Sensor)

      Remove the knock sensor.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 120 to 280 kΩ

    3. Reinstall the knock sensor.


    OK

    REPLACE ECM Click here

    NG

    REPLACE KNOCK SENSOR Click here

  4. CHECK HARNESS AND CONNECTOR (ECM - KNOCK SENSOR)


    1. Disconnect the knock sensor connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      R1-2 - B23-123 (KNK1) Always Below 1 Ω
      R1-1 - B31-124 (EKNK) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      R1-2 or B23-123 (KNK1) - Body ground Always 10 kΩ or higher

    4. Reconnect the knock sensor connector.

    5. Reconnect the ECM connector.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - KNOCK SENSOR)