What is Knock sensor and his location


What is Knock sensor and his location

What is Knock sensor?

It is a sensor that consists of a coil. This sensor is very sensitive. That is, it can sense a slight vibration. The function of this sensor is to detect a certain type of vibration that occurs when the piston moves up and down when the engine is started. This sensor tells the ECM about this vibration.

If this sensor does not detect this vibration, it signals the ECM to keep the vibration on. If the ECM does this then its ok, otherwise the knock sensor code the ECM shows us on the ODOmeter in the form of a (check engine light).

In an EFI (Electronic Fuel Injection) car, the knock sensor is a component that detects engine knock or “pinging” sounds. Knocking occurs when the fuel mixture in the engine’s combustion chamber ignites spontaneously, creating a high-pressure shock-wave that can damage the engine over time.

The knock sensor is typically located on the engine block and is connected to the vehicle’s engine control module (ECM). When the sensor detects knocking, it sends a signal to the ECM, which adjusts the engine’s ignition timing and fuel mixture to prevent knocking.

By preventing engine knock, the knock sensor helps improve engine performance, fuel economy, and overall reliability.

Location of Knock sensor :

The knock sensor is mounted on the intake or exhaust side of the cylinder block or The knock sensor is located on the outside of the engine block. It is intended to record knocking noise in all engine operating states in order to prevent engine damage.

Knock sensor and his location

Causes of Knocking :

  1. Bad Spark-Plug
  2. Bad Fuel
  3. Bad Timing
  4. Double Spark
  5. Bad Sensor
  6. Carbon

Knock Sensor to ECM Wiring Diagram

Knock Sensor wiring Check :

If the knock sensor has 3 wires, one of them will be ground wire. Use a multi-meter to find the ground wire. Set the meter to continuity and then connect one probe of the meter to the battery ground and the Second probe attach to each wire of the sensor one by one. Which wire show Continuity this will be ground wire. And of the remaining two wires, one will be 5V+ and the other will be the signal wire.

Then set the meter to 20 volts DC to find the 5 volt + wire. Connect one probe of the meter to the ground of the battery and the second probe to the remaining two wires one by one. The wire in which 5v + is visible will be the 5v + wire and the last wire will be the signal wire.