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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:

Inspection procedure
Hint: start the inspection from step 1 in case of using the handheld tester and start from step 2 in case of not using handheld tester. 1 Inspect brake actuator assy Select the datalist mode on the handheld tester.  check the operation sound of the abs pump motor when operating it ...

Listing the registered portable players
Select List Audio using .  The list of registered portable players will be displayed. ● Connecting the registered portable player to the audio system 1 Select the name of the portable player to be connected using . 2 Select Select using . ● Deleting the registered portabl ...

Circuit description
Refer to dtc p0130 Dtc no. Dtc detecting condition Trouble area P0134 After engine is warmed up, heated oxygen sensor (bank 1 sensor 1) output does not indicate rich (greater than 0.45 V) even once when conditions (a), (b), (c), (d) and (e) continue for ...

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