Lexus IS250 · Service Manual ENGINE

P0327

Diagnostic trouble codes

DESCRIPTION

A flat type knock sensor (non-resonant type) has 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. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.
DTC No.
 DTC Detection Condition
 Trouble Area
P0327
P0332
 Output voltage of knock sensor 1 or 2 is 0.5 V or less
(1 trip detection logic)
  1. Short in knock sensor 1 or 2 circuit
  1. Knock sensor 1 or 2
  1. ECM
P0328
P0333
 Output voltage of knock sensor 1 or 2 is 4.5 V or more
(1 trip detection logic)
  1. Open in knock sensor 1 or 2 circuit
  1. Knock sensor 1 or 2
  1. ECM

HINT:
When any of DTCs P0327, P0328, P0332 and P0333 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 to OFF.

Reference: Inspection using an oscilloscope
A085286E28
The correct waveform is as shown.
Item
 Content
Terminals
 KNK1 - EKNK
or
KNK2 -EKN2
Equipment Settings
 0.01 to 10 V/DIV.,
0.01 to 10 ms./DIV.
Conditions
 Keep engine speed at 4,000 rpm with warm engine

WIRING DIAGRAM

A117881E01

INSPECTION PROCEDURE

HINT:
  1. DTCs P0327 and P0328 are for the bank 1 knock sensor circuit.
  1. DTCs P0332 and P0333 are for the bank 2 knock sensor circuit.
  1. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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 (Click here).


1. READ OUTPUT DTC (CHECK KNOCK SENSOR CIRCUIT)

  1. A073822E07
    Disconnect the EG1 connector.

  1. Using lead wires, connect the connectors as follows.

    Male Connector - Female Connector
    Terminal 4 - Terminal 1
    Terminal 5 - Terminal 2
    Terminal 1 - Terminal 4
    Terminal 2 - Terminal 5

  1. Warm up the engine.

  1. Run the engine at 3,000 rpm for 10 seconds or more.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester ON.

  1. Enter the following menus: Power train / Engine / DTC.

  1. Read DTCs.

    Result:
    Display
    		 Proceed to
    DTCs same as when vehicle brought in P0327, P0328 → P0327, P0328 or P0332, P0333 → P0332, P0333
    		 A
    DTCs different from when vehicle brought in P0327, P0328 → P0332, P0333 or P0332, P0333 → P0327, P0328
    		 B

  1. Reconnect the EG1 connector.



 B
Go to step 4
A


2. CHECK WIRE HARNESS AND CONNECTOR (CONNECTOR - ECM)

  1. A107695E05
    Disconnect the EG1 connector.

  1. Disconnect the E4 ECM connector.

  1. Measure the resistance.

    Standard resistance (Check for open):
    Tester Connection
    		 Specified Condition
    EG1 female connector 4 - KNK1 (E4-28)
    		 Below 1 Ω
    EG1 female connector 5 - EKNK (E4-30)
    		 Below 1 Ω
    EG1 female connector 1 - KNK2 (E4-29)
    		 Below 1 Ω
    EG1 female connector 2 - EKN2 (E4-31)
    		 Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		 Specified Condition
    EG1 female connector 4 or KNK1 (E4-28) - Body ground
    		 10 kΩ or higher
    EG1 female connector 5 or EKNK (E4-30) - Body ground
    		 10 kΩ or higher
    EG1 female connector 1 or KNK2 (E4-29) - Body ground
    		 10 kΩ or higher
    EG1 female connector 2 or EKN2 (E4-31) - Body ground
    		 10 kΩ or higher

  1. Reconnect the EG1 connector.

  1. Reconnect the ECM connector.



 NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3. INSPECT ECM

  1. A108338E04
    Disconnect the EG1 connector.

  1. Turn the engine switch on (IG).

  1. Measure the voltage between the EG1 terminals.

    Standard voltage:
    Tester Connection
    		 Specified Condition
    EG1 female connector 4 - 5
    		 4.5 to 5.5 V
    EG1 female connector 1 - 2
    		 4.5 to 5.5 V

  1. Reconnect the ECM connector.



 NG
REPLACE ECM
OK

CHECK FOR INTERMITTENT PROBLEMS

4. INSPECT KNOCK SENSOR

  1. A072922E11
    Disconnect the EG1 connector.

  1. Measure the resistance of the EG1 male connector.

    Standard resistance:
    Tester Connection
    		 Specified Condition
    EG1 male connector 4 - 5
    		 120 to 280 kΩ
    EG1 male connector 1 - 2
    		 120 to 280 kΩ

  1. Reconnect the EG1 connector.



 OK
CHECK FOR INTERMITTENT PROBLEMS
NG


5. CHECK HARNESS AND CONNECTOR (CONNECTOR - KNOCK SENSOR)

HINT:
  1. If DTC P0327 or P0328 has changed to P0332 or P0333, check the knock sensor circuit on the right bank side.
  2. If DTC P0332 or P0333 has changed to P0327 or P0328, check the knock sensor circuit on the left bank side.

  1. A107696E05
    Disconnect the EG1 connector.

  1. Disconnect the G1 and G2 knock sensor connectors.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance (Check for open):
    Tester Connection
    		 Specified Condition
    EG1 male connector 4 - G1-2
    		 Below 1 Ω
    EG1 male connector 5 - G1-1
    		Below 1 Ω
    EG1 male connector 1 - G2-2
    		 Below 1 Ω
    EG1 male connector 2 - G2-1
    		 Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		 Specified Condition
    EG1 male connector 4 or G1-2 - Body ground
    		 10 kΩ or higher
    EG1 male connector 5 or G1-1 - Body ground
    		 10 kΩ or higher
    EG1 male connector 1 or G2-2 - Body ground
    		 10 kΩ or higher
    EG1 male connector 2 or G2-1 - Body ground
    		 10 kΩ or higher

  1. Reconnect the EG1 connector.

  1. Reconnect the knock sensor connector.



 NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE KNOCK SENSOR


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