Knock sensor: what is the normal output voltage?

  • Thread starter Thread starter Rollon
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Rollon

Hello everybody,

Thanks to "Theta00" (a user of this newsgroup), i located my knock sensor on
my Hyundai Scoupe '93. It was a diagnostic code reporting a trouble relative
to this component.
In order to see if it is really the device that is faulty, rather than a
loose/bad connection somewhere in this circuit, i connected an oscilloscope
on this device, which should be a piezoelectric component, to see what can
be his output voltage, while the engine is running. I read only 0.4 Volt
peak to peak, which i supposed to be non-normal voltage on this sensor,
piezoelectric devices delivering normally a greatest amplitude voltage. This
voltage appeared pratically immerged in the environmental noise of the
motor.

My question is: Is it a normal voltage for such a device?
If no, i'll know i have to replace it.

Thank you very much!
 
Hello everybody,

Thanks to "Theta00" (a user of this newsgroup), i located my knock sensor on
my Hyundai Scoupe '93. It was a diagnostic code reporting a trouble relative
to this component.
In order to see if it is really the device that is faulty, rather than a
loose/bad connection somewhere in this circuit, i connected an oscilloscope
on this device, which should be a piezoelectric component, to see what can
be his output voltage, while the engine is running. I read only 0.4 Volt
peak to peak, which i supposed to be non-normal voltage on this sensor,
piezoelectric devices delivering normally a greatest amplitude voltage. This
voltage appeared pratically immerged in the environmental noise of the
motor.

My question is: Is it a normal voltage for such a device?
If no, i'll know i have to replace it.

Thank you very much!
Click to expand...

the info on the knock sensor is available on the hyundai usa web site.
the normal resistance for it is 5 mega ohms.
the voltage should be less than .605v
your's may be still OK. but that doesn't help.



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