Brand:

Toyota

Model Name:

Yaris NCP90 91 92 93

Manual:

Repair Manual

Section:

1Nz-Fe Engine Control System

Title:

Sfi System

  1. Description

  2. Wiring diagram

  3. Inspection procedure

  4. Read value using intelligent tester (knock feedback value)

  5. Check harness and connector (ecm - knock sensor)

  6. Inspect ecm (knk1 voltage)

  7. Inspect knock 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)


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DESCRIPTION

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

DTC No.
DTC Detection Conditions
Trouble Areas
P0327
Output voltage of knock sensor is 0.5 V or less
(1 trip detection logic)
  1. Short in knock sensor circuit
  2. Knock sensor
  3. ECM
P0328
Output voltage of knock sensor is 4.5 V or more
(1 trip detection logic)
  1. Open in knock sensor circuit
  2. Knock sensor
  3. ECM
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
Connect an intelligent tester to the DLC3. Yaris
The correct waveform is as shown.
Item
Content
Terminals
KNK1 - EKNK
Equipment Settings
1 V/Division,
1 msec./Division
Conditions
Keep engine speed at 4,000 rpm with warm engine

WIRING DIAGRAM


Connect an intelligent tester to the DLC3. Yaris


INSPECTION PROCEDURE

HINT:
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.
1.READ VALUE USING INTELLIGENT TESTER (KNOCK FEEDBACK VALUE)

  1. Connect an intelligent tester to the DLC3.

  1. Start the engine and turn the tester on.

  1. Warm up the engine.

  1. Select the following menu items: Powertrain / Engine and ECT / Data List / Knock Feedback Value.

  1. Read the values displayed on the tester while driving the vehicle.

    Standard:
    The values change.
    HINT:
    Malfunction does not occur
    		Knock Feedback Values change
    Malfunctions occur
    		Knock Feedback Values do not change
    The knock feedback value change can be confirmed by running the engine at high load, for example, by activating the air conditioning system and racing the engine.


OKnext
CHECK FOR INTERMITTENT PROBLEMS (Click here)
NG
next down

2.CHECK HARNESS AND CONNECTOR (ECM - KNOCK SENSOR)
Disconnect the C20 ECM connector. Yaris

  1. Disconnect the C20 ECM connector.

  1. Measure the resistance between the terminals.

    Standard resistance:
    Tester Connections
    		Specified Conditions
    KNK1 (C20-110) - EKNK (C20-111)
    		120 to 280 kΩ at 20°C (68°F)

  1. Reconnect the ECM connector.



NGnext
Go to step 4
OK
next down

3.INSPECT ECM (KNK1 VOLTAGE)
Disconnect the P1 knock sensor connector. Yaris

  1. Disconnect the P1 knock sensor connector.

  1. Turn the ignition switch to ON.

  1. Measure the voltage between the knock sensor terminals.

    Standard voltage:
    Tester Connections
    		Specified Conditions
    KNK1 (P1-2) - EKNK (P1-1)
    		4.5 to 5.5 V

  1. Reconnect the knock sensor connector.



NGnext
REPLACE ECM (Click here)
OK
next down
CHECK FOR INTERMITTENT PROBLEMS (Click here)

4.INSPECT KNOCK SENSOR
Remove the knock sensor (Click here). Yaris

  1. Remove the knock sensor (Click here).

  1. Measure the resistance between the terminals.

    Standard resistance:
    Tester Connections
    		Specified Conditions
    KNK1 (2) - EKNK (1)
    		120 to 280 kΩ at 20°C (68°F)

  1. Reinstall the knock sensor (Click here).



NGnext
REPLACE KNOCK SENSOR (Click here)
OK
next down
REPAIR OR REPLACE HARNESS OR CONNECTOR