SFI 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 No. DTC Detection Condition Trouble Area
P0327

Output voltage of knock sensor (bank 1 sensor 1) is 0.5 V or less

(1 trip detection logic)

  • Short in knock sensor (bank 1 sensor 1) circuit


  • Knock sensor (bank 1 sensor 1)


  • ECM
P0328

Output voltage of knock sensor (bank 1 sensor 1) is 4.5 V or more

(1 trip detection logic)

  • Open in knock sensor (bank 1 sensor 1) circuit


  • Knock sensor (bank 1 sensor 1)


  • ECM
P0332

Output voltage of knock sensor (bank 2 sensor 1) is 0.5 V or less

(1 trip detection logic)

  • Short in knock sensor (bank 2 sensor1) circuit


  • Knock sensor (bank 2 sensor 1)


  • ECM
P0333

Output voltage of knock sensor (bank 2 sensor 1) is 4.5 V or more

(1 trip detection logic)

  • Open in knock sensor (bank 2 sensor1) circuit


  • Knock sensor (bank 2 sensor 1)


  • ECM
P032C

Output voltage of knock sensor (bank 1 sensor 2) is 0.5 V or less

(1 trip detection logic)

  • Short in knock sensor (bank 1 sensor 2) circuit


  • Knock sensor (bank 1 sensor 2)


  • ECM
P032D

Output voltage of knock sensor (bank 1 sensor 2) is 4.5 V or more

(1 trip detection logic)

  • Open in knock sensor (bank 1 sensor 2) circuit


  • Knock sensor (bank 1 sensor 2)


  • ECM
P033C

Output voltage of knock sensor (bank 2 sensor 2) is 0.5 V or less

(1 trip detection logic)

  • Short in knock sensor (bank 2 sensor 2) circuit


  • Knock sensor (bank 2 sensor 2)


  • ECM
P032D

Output voltage of knock sensor (bank 2 sensor 2) is 4.5 V or more

(1 trip detection logic)

  • Open in knock sensor (bank 2 sensor 2) circuit


  • Knock sensor (bank 2 sensor2)


  • ECM

Tech Tips

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

Reference: Inspection using an oscilloscope

A01GL7EE01

The correct waveform is as shown.

Item Content
Terminal

KNK1 - EKNK

KNK2 - EKN2

KNK3 - EKN3

KNK4 - EKN4
Equipment Setting

0.01 to 10 V/DIV.

0.01 to 10 msec./DIV.
Condition Keep engine speed at 4000 rpm with warm 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 sets a DTC.

WIRING DIAGRAM

A01GNH9E09

INSPECTION PROCEDURE

Tech Tips


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

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

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

PROCEDURE


  1. INSPECT KNOCK SENSOR

    A01GI2EE02

    1. Disconnect the E3 ECM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      E3-26 (KNK1) - E3-33 (EKNK) 20°C (68°F) 120 to 280 kΩ
      E3-25 (KNK2) - E3-32 (EKN2) 20°C (68°F) 120 to 280 kΩ
      E3-24 (KNK3) - E3-31 (EKN3) 20°C (68°F) 120 to 280 kΩ
      E3-23 (KNK4) - E3-30 (EKN4) 20°C (68°F) 120 to 280 kΩ

    OK

    INSPECT ECM Click here

    NG

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

    A01GJ8CE01

    1. Disconnect the E3 ECM connector.

    2. Disconnect the H14, H10, H12 or H7 knock sensor connector.

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      E3-26 (KNK1) - H14-2 Always Below 1 Ω
      E3-33 (EKNK) - H14-1 Always Below 1 Ω
      E3-25 (KNK2) - H10-2 Always Below 1 Ω
      E3-32 (EKN2) - H10-1 Always Below 1 Ω
      E3-24 (KNK3) - H12-2 Always Below 1 Ω
      E3-31 (EKN3) - H12-1 Always Below 1 Ω
      E3-23 (KNK4) - H7-2 Always Below 1 Ω
      E3-30 (EKN4) - H7-1 Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      E3-26 (KNK1) or H14-2 - Body ground Always 10 kΩ or higher
      E3-33 (EKNK) or H14-1 - Body ground Always 10 kΩ or higher
      E3-25 (KNK2) or H10-2 - Body ground Always 10 kΩ or higher
      E3-32 (EKN2) or H10-1 - Body ground Always 10 kΩ or higher
      E3-24 (KNK3) or H12-2 - Body ground Always 10 kΩ or higher
      E3-31 (EKN3) or H12-1 - Body ground Always 10 kΩ or higher
      E3-23 (KNK4) or H7-2 - Body ground Always 10 kΩ or higher
      E3-30 (EKN4) or H7-1 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE KNOCK SENSOR Click here

  3. INSPECT ECM


    1. A01GKS8E03

      Turn the engine switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      E3-26 (KNK1) - E3-33 (EKNK) Engine switch on (IG) 4.5 to 5.5 V
      E3-25 (KNK2) - E3-32 (EKN2) Engine switch on (IG) 4.5 to 5.5 V
      E3-24 (KNK3) - E3-31 (EKN3) Engine switch on (IG) 4.5 to 5.5 V
      E3-23 (KNK4) - E3-30 (EKN4) Engine switch on (IG) 4.5 to 5.5 V

    NG

    REPLACE ECM Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here