P0327

2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0327,P0328: Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

DTC P0327 - Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

DTC P0328 - Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

DESCRIPTION

Flat type knock sensors (non-resonant type) have structures that can detect vibrations over a wide band of frequencies: between approximately 6 kHz and 15 kHz.
Knock sensor is 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.

HINT: When any of DTCs P0327 and P0328 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 ignition switch is turned off.

Reference: Inspection using an oscilloscope

The correct waveform is as shown.

MONITOR DESCRIPTION

If the output voltage transmitted by the knock sensor remains low or high for more than 1 second, the ECM interprets this as a malfunction in the sensor circuit, and sets a DTC.
The monitor for DTCs P0327 and P0328 begins to run when 5 seconds have elapsed since the engine was started.
If the malfunction is not repaired successfully, either DTC P0327 or P0328 is set 5 seconds after the engine is next started.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

Knock Sensor Range Check (Low voltage) P0327:

Knock Sensor Range Check (High voltage) P0328:

WIRING DIAGRAM

INSPECTION PROCEDURE
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 VALVE)
(a) Connect the Techstream to the DLC3.
(b) Start the engine and turn the tester on.
(c) Warm up the engine.
(d) Select the following menu items: Powertrain / Engine and ECT / Data List / Knock Feedback Value.
(e) Read the values displayed on the tester while driving the vehicle.
Standard:
The values change.

HINT

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 revving up the engine.

NG -- CHECK HARNESS AND CONNECTOR (ECM - KNOCK SENSOR)
OK -- CHECK FOR INTERMITTENT PROBLEMS
2. CHECK HARNESS AND CONNECTOR (ECM - KNOCK SENSOR)

(a) Disconnect the C24 ECM connector.
(b) Measure the resistance between the terminals.
Standard resistance:

(c) Reconnect the ECM connector.
NG -- INSPECT KNOCK SENSOR
OK -- Continue to next step.
3. INSPECT ECM (KNK1 VOLTAGE)

(a) Disconnect the C30 knock sensor connector.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage between the knock sensor terminals.
Standard voltage:

(d) Reconnect the knock sensor connector.
NOTICE: Fault may be intermittent. Check the wire harness and connectors carefully and retest.

NG -- REPLACE ECM
OK -- CHECK FOR INTERMITTENT PROBLEMS
4. INSPECT KNOCK SENSOR

(a) Remove the knock sensor.
(b) Measure the resistance between the terminals.
Standard resistance: