Lexus NX: Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor) (P0327,P0328)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (engine Control) / Sfi System / Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor) (P0327,P0328)

DESCRIPTION

A flat type knock control sensor (non-resonant type) has a structure that can detect vibration between approximately 5 kHz and 23 kHz.

The knock control sensors are fitted onto the engine block to detect engine knocking.

The knock control 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.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0327

Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

Output voltage of knock control sensor is less than 0.5 V for 1 second or more (1 trip detection logic).

  • Short in knock control sensor circuit
  • Knock control sensor
  • ECM

Comes on

DTC stored

P0328

Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

Output voltage of knock control sensor is higher than 4.5 V for 1 second or more (1 trip detection logic).

  • Open in knock control sensor circuit
  • Knock control sensor
  • ECM

Comes on

DTC stored

HINT:

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 power switch is turned off.

Reference: Inspection using an oscilloscope

HINT:

The correct waveform is as shown.

ECM Terminal Name

Between KNK1 and EKNK

Tester Range

1 V/DIV., 1 ms./DIV.

Condition

Engine speed maintained at 2500 rpm after warming up engine

MONITOR DESCRIPTION

If the output voltage transmitted by the knock control sensor remains low or high for 1 second or more, the ECM interprets this as a malfunction in the sensor circuit, and stores a DTC.

The monitor for DTCs P0327 and P0328 begins to run when 5 seconds have elapsed since the engine was started.

MONITOR STRATEGY

Related DTCs

P0327: Knock control sensor range check (low voltage)

P0328: Knock control sensor range check (high voltage)

Required Sensors/Components (Main)

Knock control sensor

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

1 second

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

All of the following conditions are met

-

Time after engine start

5 seconds or more

Auxiliary battery voltage

10.5 V or higher

Power switch

On (IG)

TYPICAL MALFUNCTION THRESHOLDS

P0327: Knock Control Sensor Range Check (Low Voltage)

Knock control sensor voltage

Less than 0.5 V

P0328: Knock Control Sensor Range Check (High Voltage)

Knock control sensor voltage

Higher than 4.5 V

COMPONENT OPERATING RANGE

Knock control sensor voltage

0.5 to 4.5 V

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG) and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the power switch off and wait for at least 30 seconds.
  5. Turn the power switch on (IG) and turn the Techstream on.
  6. Put the engine in inspection mode (maintenance mode).

    Click here

  7. Start the engine and wait 5 minutes.
  8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  9. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  11. Input the DTC: P0327 or P0328
  12. Check the DTC judgment result.

    Techstream Display

    Description

    NORMAL

    • DTC judgment completed
    • System normal

    ABNORMAL

    • DTC judgment completed
    • System abnormal

    INCOMPLETE

    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    N/A

    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, idle the engine for 5 minutes and check the DTC judgment result again.
  13. If no pending DTC is output, perform a universal trip and check for permanent DTCs.

    Click here

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 TECHSTREAM (KNOCK FEEDBACK VALUE)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Put the engine in inspection mode (maintenance mode).

Click here

Powertrain > Hybrid Control > Utility

Tester Display

Inspection Mode

(e) Start the engine.

(f) Warm up the engine.

(g) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Knock Feedback Value.

Powertrain > Engine and ECT > Data List

Tester Display

Knock Feedback Value

(h) Read the value while driving the vehicle.

OK:

The value changes.

Malfunction does not occur

Knock Feedback Value changes

Malfunctions occur

Knock Feedback Value does not change

HINT:

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.

OK

CHECK FOR INTERMITTENT PROBLEMS

NG

2.

CHECK TERMINAL VOLTAGE (POWER SOURCE OF KNOCK CONTROL SENSOR)

*a

Front view of wire harness connector

(to Knock Control Sensor)

(a) Disconnect the knock control sensor connector.

(b) Turn the power switch on (IG).

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

a1-2 - a1-1

Power switch on (IG)

4.5 to 5.5 V

NG

GO TO STEP 4

OK

3.

INSPECT KNOCK CONTROL SENSOR

(a) Inspect the knock control sensor.

Click here

HINT:

Perform "Inspection After Repair" after replacing the knock control sensor.

Click here

OK

REPLACE ECM

NG

REPLACE KNOCK CONTROL SENSOR

4.

CHECK HARNESS AND CONNECTOR (KNOCK CONTROL SENSOR - ECM)

(a) Disconnect the knock control sensor connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

a1-2 - C48-123 (KNK1)

Always

Below 1 Ω

a1-1 - C48-124 (EKNK)

Always

Below 1 Ω

a1-2 or C48-123 (KNK1) - Body ground

Always

10 kΩ or higher

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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