P032C

1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0327, P0328, P032C, P032D, P0332, P0333, P033C, P033D: Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)


DESCRIPTION

A flat type knock sensor (non-resonant type) has a structure that can detect vibrations between approximately 6 kHz and 15 kHz.

Knock sensors are 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 DTC P0327, P0328, P0332, P0333, P032C, P032D, P033C or P033D is 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 engine switch is turned off.

Reference: Inspection using an oscilloscope





The correct waveform is as shown.





MONITOR DESCRIPTION

The knock sensor, located on the cylinder block, detects spark knock. When spark knock occurs, the piezoelectric element of the sensor vibrates. When the ECM detects a voltage in this frequency range, it retards the ignition timing to suppress the spark knock.

The ECM also senses background engine noise with the knock sensor and uses this noise to check for faults in the sensor. If the knock sensor signal level is too low for more than 10 seconds, or if the knock sensor output voltage is outside the normal range, the ECM interprets this as a fault in the knock sensor and sets a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

Knock Sensor Range Check (Low voltage): P0327, P0332, P032C and P033C:





Knock Sensor Range Check (High voltage): P0328, P0333, P032D and P033D:





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Start the engine and wait 10 seconds.

7. Enter the following menus: Powertrain / Engine / Trouble Codes.

8. Read the DTCs [B].

HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

10. Input the DTC: P0327, P0328, P032C, P032D, P0332, P0333, P033C or P033D.

11. Check the DTC judgment result.





HINT
If the judgment result shows INCOMPLETE or N/A, idle the engine for 5 minutes and check the DTC judgment result again [C].

12. If the test result INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

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

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
- DTCs P0327 and P0328 are for the bank 1 sensor 1 knock sensor circuit.
- DTCs P032C and P032D are for the bank 1 sensor 2 knock sensor circuit.
- DTCs P0332 and P0333 are for the bank 2 sensor 1 knock sensor circuit.
- DTCs P033C and P033D are for the bank 2 sensor 2 knock sensor circuit.
- Bank 1 refers to the bank that includes the No. 1 cylinder*.
*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
- Bank 2 refers to the bank that does not include the No. 1 cylinder.
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition 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

1. INSPECT KNOCK SENSOR





(a) Disconnect the E3 ECM connector.

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

Standard resistance:





OK -- INSPECT ECM
NG -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (KNOCK SENSOR - ECM)





(a) Disconnect the H14, H10, H12 or H7 knock sensor connector.

(b) Disconnect the E3 ECM connector.

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

Standard resistance (Check for open):





Standard resistance (Check for open):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE KNOCK SENSOR Removal

3. INSPECT ECM

(a) Turn the engine switch on (IG).





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

Standard voltage:





NG -- REPLACE ECM Removal

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems