SFI SYSTEM(w/o Secondary Air Injection System), Diagnostic DTC:P0327, P0328, P032C, P032D, P0332, P0333, P033C, P033D

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)
P032C Knock Sensor 3 Circuit Low
P032D Knock Sensor 3 Circuit High
P0332 Knock Sensor 2 Circuit Low Input (Bank 2)
P0333 Knock Sensor 2 Circuit High Input (Bank 2)
P033C Knock Sensor 4 Circuit Low Input
P033D Knock Sensor 4 Circuit High Input

DESCRIPTION

A flat type knock sensor (non-resonant type) has a structure that can detect vibrations 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. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.

DTC Code DTC Detection Condition Trouble Area
P0327 The output voltage of the knock sensor (for Bank 1 Sensor 1) is 0.5 V or less (1 trip detection logic).

  • Short in knock sensor (for Bank 1 Sensor 1) circuit


  • Knock sensor (for Bank 1 Sensor 1)


  • ECM
P0328 The output voltage of the knock sensor (for Bank 1 Sensor 1) is 4.5 V or higher (1 trip detection logic).

  • Open in knock sensor (for Bank 1 Sensor 1) circuit


  • Knock sensor (for Bank 1 Sensor 1)


  • ECM
P0332 The output voltage of the knock sensor (for Bank 2 Sensor 1) is 0.5 V or less (1 trip detection logic).

  • Short in knock sensor (for Bank 2 Sensor1) circuit


  • Knock sensor (for Bank 2 Sensor 1)


  • ECM
P0333 The output voltage of the knock sensor (for Bank 2 Sensor 1) is 4.5 V or higher (1 trip detection logic).

  • Open in knock sensor (for Bank 2 Sensor1) circuit


  • Knock sensor (for Bank 2 Sensor 1)


  • ECM
P032C The output voltage of the knock sensor (for Bank 1 Sensor 2) is 0.5 V or less (1 trip detection logic).

  • Short in knock sensor (for Bank 1 Sensor 2) circuit


  • Knock sensor (for Bank 1 Sensor 2)


  • ECM
P032D The output voltage of the knock sensor (for Bank 1 Sensor 2) is 4.5 V or higher (1 trip detection logic).

  • Open in knock sensor (for Bank 1 Sensor 2) circuit


  • Knock sensor (for Bank 1 Sensor 2)


  • ECM
P033C The output voltage of the knock sensor (for Bank 2 Sensor 2) is 0.5 V or less (1 trip detection logic).

  • Short in knock sensor (for Bank 2 Sensor 2) circuit


  • Knock sensor (for Bank 2 Sensor 2)


  • ECM
P033D The output voltage of the knock sensor (for Bank 2 Sensor 2) is 4.5 V or higher (1 trip detection logic).

  • Open in knock sensor (for Bank 2 Sensor 2) circuit


  • Knock sensor (for Bank 2 Sensor 2)


  • ECM

Tech Tips

When any of DTCs P0327, P0328, P0332, P0333, P032C, P032D, P033C and P033D 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 engine switch is turned off.

Reference: Inspection using an oscilloscope.

B001WQOE26
*a KNK1 Signal Waveform
*b 1 V/DIV.
*c 1 msec./DIV.
Standard
Tester Connection Tool Setting Condition Specified Condition
C45-94 (KNK1) - C45-93 (EKNK)

0.01 to 10 V/DIV.

0.01 to 10 msec./DIV.

 Keep engine speed at 4000 rpm with warm engine The correct waveform is as shown
C45-117 (KNK2) - C45-116 (EKN2)

0.01 to 10 V/DIV.

0.01 to 10 msec./DIV.

 Keep engine speed at 4000 rpm with warm engine The correct waveform is as shown
C45-92 (KNK3) - C45-91 (EKN3)

0.01 to 10 V/DIV.

0.01 to 10 msec./DIV.

 Keep engine speed at 4000 rpm with warm engine The correct waveform is as shown
C45-115 (KNK4) - C45-114 (EKN4)

0.01 to 10 V/DIV.

0.01 to 10 msec./DIV.

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

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 DTC(s).

WIRING DIAGRAM

B001X39E16

CAUTION / NOTICE / HINT

Tech Tips


  • DTCs P0327 and P0328 are for the bank 1 sensor 1 knock sensor circuit.

  • DTCs P032C and P032D are for the bank 1 sensor 2 knock sensor circuit.

  • DTCs P0332 and P0333 are for the bank 2 sensor 1 knock sensor circuit.

  • DTCs P033C and P033D are for the bank 2 sensor 2 knock sensor circuit.

  • 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.

  • Bank 1 refers to the bank that includes the No. 1 cylinder*.

    *: The No. 1 cylinder is the cylinder which is farthest from the transmission.

  • Bank 2 refers to the bank that does not include the No. 1 cylinder.

PROCEDURE


  1. INSPECT KNOCK SENSOR

    B001ZSRE02
    *1 Front view of wire harness connector: (to ECM)

    1. Disconnect the C45 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C45-94 (KNK1) - C45-93 (EKNK) 20°C (68°F) 120 to 280 kΩ
      C45-117 (KNK2) - C45-116 (EKN2) 20°C (68°F) 120 to 280 kΩ
      C45-92 (KNK3) - C45-91 (EKN3) 20°C (68°F) 120 to 280 kΩ
      C45-115 (KNK4) - C45-114 (EKN4) 20°C (68°F) 120 to 280 kΩ
      Result
      Result Proceed to
      NG A
      OK B

    B

    INSPECT ECM Click here

    A

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


    1. Disconnect the C45 ECM connector.

    2. Disconnect the U3, U4, U5 or U6 knock sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U3-2 - C45-94 (KNK1) Always Below 1 Ω
      U3-1 - C45-93 (EKNK) Always Below 1 Ω
      U4-2 - C45-117 (KNK2) Always Below 1 Ω
      U4-1 - C45-116 (EKN2) Always Below 1 Ω
      U5-2 - C45-92 (KNK3) Always Below 1 Ω
      U5-1 - C45-91 (EKN3) Always Below 1 Ω
      U6-2 - C45-115 (KNK4) Always Below 1 Ω
      U6-1 - C45-114 (EKN4) Always Below 1 Ω
      U3-2 or C45-94 (KNK1) - Body ground Always 10 kΩ or higher
      U3-1 or C45-93 (EKNK) - Body ground Always 10 kΩ or higher
      U4-2 or C45-117 (KNK2) - Body ground Always 10 kΩ or higher
      U4-1 or C45-116 (EKN2) - Body ground Always 10 kΩ or higher
      U5-2 or C45-92 (KNK3) - Body ground Always 10 kΩ or higher
      U5-1 or C45-91 (EKN3) - Body ground Always 10 kΩ or higher
      U6-2 or C45-115 (KNK4) - Body ground Always 10 kΩ or higher
      U6-1 or C45-114 (EKN4) - Body ground Always 10 kΩ or higher

    OK

    REPLACE KNOCK SENSOR Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. INSPECT ECM


    1. B001ZV9E02
      *1 Front view of wire harness connector: (to Knock Sensor)

      Disconnect the U3, U4, U5 or U6 knock sensor connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      U3-1 - U3-2 Engine switch on (IG) 4.5 to 5.5 V
      U4-1 - U4-2 Engine switch on (IG) 4.5 to 5.5 V
      U5-1 - U5-2 Engine switch on (IG) 4.5 to 5.5 V
      U6-1 - U6-2 Engine switch on (IG) 4.5 to 5.5 V

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    REPLACE ECM Click here