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

Flat-type knock sensors (non-resonant type) have structures that can detect vibrations between approximately 6 kHz and 15 kHz.

The knock sensor is 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. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.

DTC No. DTC Detection Condition Trouble Area
P0327 The output voltage of the knock sensor is below 0.5 V (1 trip detection logic).
  • Short in knock sensor circuit

  • Knock sensor

  • ECM

P0328 The output voltage of knock sensor is higher than 4.5 V (1 trip detection logic).
  • Open in knock sensor circuit

  • Knock sensor

  • ECM

Tech Tips

When DTC P0327 or P0328 is stored, 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

A00DPUVE02

The correct waveform is as shown.

Item Content
Terminal KNK1 - EKNK
Equipment Setting

1 V/DIV.

1 ms./DIV.

Condition Engine speed maintained at 4000 rpm after engine warmed-up

WIRING DIAGRAM

A00DTO1E01

INSPECTION PROCEDURE

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 / Knock Feedback Value.

    6. Read the values displayed on the tester while the vehicle is being driving.

      OK
      The values change.

      Tech Tips

      Malfunction does not occur Knock Feedback Values change
      Malfunction occurs Knock Feedback Values do 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.


    NG
    OK
  2. INSPECT ECM (KNK1 VOLTAGE)


    1. A00DU87E03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Knock Sensor)

      Disconnect the knock sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C1-2 (KNK1) - C1-1 (EKNK) Ignition switch ON 4.5 to 5.5 V
    3. Reconnect the knock sensor connector.


    NG
    OK
  3. INSPECT KNOCK SENSOR


    1. A00DTDPE03
      Text in Illustration
      *1

      Component without harness connected

      (Knock Sensor)

      *2 Ohmmeter

      Remove the knock sensor.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (KNK1) - 1 (EKNK) 20°C (68°F) 120 to 280 kΩ
    3. Reinstall the knock sensor.


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


    1. A00DR9TE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Knock Sensor)

      *2

      Front view of wire harness connector

      (to ECM)

      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
      C1-2 (KNK1) - B39-110 (KNK1) Always Below 1 Ω
      C1-1 (EKNK) - B39-111 (EKNK) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C1-2 (KNK1) or B39-110 (KNK1) - Body ground Always 10 kΩ or higher
      C1-1 (EKNK) or B39-111 (EKNK) - Body ground Always 10 kΩ or higher
    4. Reconnect the knock sensor connector.

    5. Reconnect the ECM connector.


    NG
    OK