СИСТЕМА SFI, Diagnostic DTC:P0327/52, P0328/52

DTC Code	DTC Name
P0327/52	Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
P0328/52	Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

DESCRIPTION

The flat type knock sensor (non-resonant type) has a structure that can detect vibration in a wide band of frequency from about 6 to 15 kHz and has the following features:

The knock sensor is fitted on the cylinder block to detect engine knocking.

The sensor contains a piezoelectric element which generates voltage when it becomes deformed. This occurs when the cylinder block vibrates due to knocking. If engine knocking occurs, the ignition timing is retarded to suppress it.

DTC No.	DTC Detection Condition	Suspected Area
P0327/52	Output voltage of the knock sensor is 0.5 V or less	Short in knock sensor circuit Knock sensor ECM
P0328/52	Output voltage of the knock sensor is 4.5 V or more	Open in knock sensor circuit Knock sensor ECM

MONITOR DESCRIPTION

If the output signal remains low or high for more than 10 seconds, the ECM interprets this as a fault in the knock sensor and sets a DTC.

The monitor for DTC P0327/52 and P0328/52 runs after the engine is started and 5 seconds have passed.

WIRING DIAGRAM

INSPECTION PROCEDURE

Tech Tips

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.

PROCEDURE

CHECK WIRE HARNESS (ECM - KNOCK SENSOR)

Disconnect the E12 ECM connector.

Measure the resistance of the wire harness side connector.

Standard resistance

Tester Connection	Specified Condition
E12-29 (KNK1) - E12-30 (EKNK)	120 to 280 kΩ at 20°C (68°F)

INSPECT KNOCK SENSOR Click here

CHECK ECM (KNK1 VOLTAGE)

Turn the ignition switch ON.

Measure the voltage of the ECM connector.

Standard voltage

Tester Connection	Specified Condition
E12-29 (KNK1) - E12-30 (EKNK)	4.5 to 5.5 V

Tech Tips

Reference: Inspect using the oscilloscope.

Check the waveform of the ECM connector.

Standard

Tester Connection	Specified Condition
E12-29 (KNK1) - E12-30 (EKNK)	Correct waveform is as shown

Tool Setting	Condition
0.01 to 10 V/Div., 0.01 to 10 msec./Div.	After warming up engine, keep engine speed at 4,000 rpm

Note

Fault may be intermittent. Check the wire harness and connectors carefully.

REPLACE ECM

CHECK FOR INTERMITTENT PROBLEMS

INSPECT KNOCK SENSOR

Remove the sensor.

Measure the resistance of the sensor.

Standard resistance

Tester Connection	Condition	Specified Condition
1 - 2	20°C (68°F)	120 to 280 kΩ

REPLACE KNOCK SENSOR

REPAIR OR REPLACE HARNESS AND CONNECTOR