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Toyota Corolla Repair Manual: Circuit description

A flat type knock sensor (nonresonant type) has the structure that can detect the vibration in a wider band of frequency from about 6 khz to 15 khz and has the following features.

Knock sensors are fitted on the cylinder block to detect the engine knocking.

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

Hint:

Hint

: if the ecm detects the dtc p0325, it enters the failsafe mode in which the corrective retarded angle value is set to the maximum value.

Reference: inspection using the oscilloscope.

Reference: inspection using the oscilloscope.

  1.  After warming up run the engine at 4,000 rpm, check the waveform between terminal knk1 and eknk of the ecm connector.

Monitor description

The knock sensor, located on the cylinder block, detects spark knock. When spark knock occurs, the sensor picksup vibrates in a specific frequency range. When the ecm detects the 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, and if the knock sensor output voltage is out of normal range, the ecm interprets this as a fault in the knock sensor and sets a dtc.

Monitor strategy

Typical enabling conditions

Typical enabling conditions

Typical malfunction thresholds

Typical malfunction thresholds

Wiring diagram

Wiring diagram

Inspection procedure

Knock sensor 1 circuit
Dtc p0325 knock sensor 1 circuit (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 senso ...

Inspection procedure
Hint: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is usefu ...

Other materials:

Onvehicle inspection
1. Inspect wireless door lock control functions Hint: the switch described in this text is a switch for transmitting signals (lock switch, unlock switch and panic switch) which is built into the door control transmitter. All the functions listed below must be checked in the remote contro ...

Circuit description
Refer to dtcs p0100 Dtc no. Dtc detection condition Trouble area P0101 After engine is warmed up, conditions (a) to (d) continue for more than 10 seconds (2 trip detection logic):  engine speed less than 900 rpm  throttle valve fully closed &nbs ...

Inspection procedure
1 Check door lock When the door does not operate manually, proceed to a.  when the door does not operate via the key, proceed to b. 2 Inspect door lock control switch W/ power window: remove the power window regulator master switch assy.  Inspect the master ...

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