SFI SYSTEM (w/o Secondary Air Injection 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 (non-resonant type) has a structure that can detect vibrations between approximately 5 kHz and 15 kHz.

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

Each 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 Output voltage of the knock sensor is 0.5 V or less (1 trip detection logic).

  • Short in knock sensor circuit


  • Knock sensor


  • ECM
P0328 Output voltage of the knock sensor is 4.5 V or higher (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. The ECM continues operating in fail-safe mode until the ignition switch is turned off.

Reference: Inspection using an oscilloscope

A003B5FE01
Tester Connection Tool Setting Condition Specified Condition
D97-110 (KNK1) - D97-111 (EKNK)

1 V/DIV.

1 msec./DIV.

 Engine speed at 4000 rpm with warm engine The correct waveform is as shown

MONITOR DESCRIPTION

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 output voltage is outside the normal range, the ECM interprets this as a fault in the knock sensor and stores a DTC.

WIRING DIAGRAM

A003AQ8E05

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. INSPECT KNOCK SENSOR


    1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D97-110 (KNK1) - D97-111 (EKNK) 20°C (68°F) 120 to 280 kΩ

    NG

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

    OK

  2. INSPECT ECM

    A003FSOE53
    Text in Illustration
    *1 Female
    *a

    Front view of wire harness connector

    (to ECM Wire)

    1. Disconnect the Dg1 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
      Dg1 female connector 1 - 2 Ignition switch ON 4.5 to 5.5 V

    NG

    REPLACE ECM Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

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


    1. Disconnect the ECM connector.

    2. Disconnect the knock sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      g1-2 - D97-110 (KNK1) Always Below 1 Ω
      g1-1 - D97-111 (EKNK) Always Below 1 Ω
      g1-2 or D97-110 (KNK1) - Body ground Always 10 kΩ or higher
      g1-1 or D97-111 (EKNK) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE KNOCK SENSOR Click here