Engine performance diagnostics chapter 10 pages 6 7.
Knock sensor resistance value.
Very high combustion temperatures.
Detonation is the result of fuel and air mixture exploding quickly instead of burning evenly.
Although you ll be able to tell if it s completely dead service manual calls for tapping on the side of the block with something metalic and making sure sensor outputs a knock reading.
The knock sensor within your vehicle is a component designed to listen for engine detonation or knocking.
Verify that the voltage at the sensor is within the range suggested in your user manual.
I suppose you can compare voltage output of your sensor to.
Malfunction indicator lamp mil illumination.
Other manufactures are doing the same thing making the circuit very easy to test.
Bad knock sensor symptoms.
The particular knock sensor i was testing measured at about 6 7nf temperature dependant sensor alone or 7 5nf with the wiring.
This procedure applies to any knock sensor that has a bias voltage sent to it and is not unique to nissan.
The test is very simple i have unplugged the sensor from the ecu plugged one probe form the multimeter set to capacitance range to the pin for the knock sensor on the ecu plug and another on chassis earth ground.
The knock sensor detects vibrations that come from a knock or an irregularity in combustion and send a signal to the engine control computer which then adjusts timing to correct the knock.
Consistent engine knock and associated sensor faults may cause the following symptoms.
Since knock sensor is practically a microphone testing proper operation of is rather hard.
Turn on the power source.
Lean air fuel ratio causing high temperature.
If so we ve eliminated source voltage as the problem.
In this video i will show you how to quickly test a knock sensor circuit.
If not the voltage source is at least a problem if not the.
Select the dcv value on the multimeter that is closest to yet bigger than the source voltage.
Carbon deposits pre igniting the air fuel mixture.
