Toyota Corolla (E120): Circuit description

A flat type knock sensor (non–resonant 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 fail–safe 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 picks–up 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

    Share this page:

    Other materials:

    Circuit description
    When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in high concentrations. If this hc concentration is high enough, there could be an increase in exhaust emissions levels. High concentrations of hc passing through the catalyst also cause to temperature of the catalyst to ...

    Calling the message sender
    Calls can be made to an e-mail/SMS/MMS message sender's phone number. 1 Display the “Message Inbox” screen. 2 Select the desired message. 3 Select . 4 Check that the “Call” screen is displayed. ■ Calling from a number within a message Calls can be made to a number identified ...

    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 ...