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

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the Techstream on.
Put the engine in inspection mode (maintenance mode).
Click here
Start the engine and wait 5 minutes.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
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.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0327 or P0328

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.

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).

(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.

CHECK FOR INTERMITTENT PROBLEMS

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).

Standard Voltage:

Tester Connection	Condition	Specified Condition
a1-2 - a1-1	Power switch on (IG)	4.5 to 5.5 V

GO TO STEP 4

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

REPLACE ECM

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.

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

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

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