how does a knock sensor work? [Archive]

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00 scrub

06-04-2002, 10:23 PM

how does a knock sensor work? How does it detect pinging in the engine??

Griffin

06-05-2002, 07:28 AM

In the single wire type there is a crystal in it that generates a voltage when it is "shocked" by a knock event. The voltage increases in proportion to severity. It can only be viewed as a waveform on an oscilliscope.

In the new twin wire design there is still a crystal, but this one changes resistance as exposed to knock rather than generating a voltage. It is more sensitive and has a larger range.

The computer monitor the voltage / output from the sensors to determine teh presence of knock.

Griffin

GTS LAID

06-05-2002, 09:21 PM

the coolest sensor is the g22... i'll let you guys figure out which one that is but it works by using the changes in the magnetic field induced by a greater air gap while the "part" turns...

Griffin

06-07-2002, 07:50 AM

Originally posted by GTS LAID
the coolest sensor is the g22... i'll let you guys figure out which one that is but it works by using the changes in the magnetic field induced by a greater air gap while the "part" turns...

Actually its just the "G2" signal - the sensor is called the Camshaft position sensor or the VVTi sensor. The crankshaft position sensor works the same way.

Grins - hey I gave everyone else a day to answer :)

Griffin

GTS LAID

06-07-2002, 11:23 AM

yup yup yup/// same one... damn people need to start reading their manuals.

Chui

06-07-2002, 07:27 PM

Yes, a knock sensor is a piezoelectric accelerometer.

00 scrub

06-09-2002, 01:34 PM

ok this makes sense. Thsnks for the info.

Jesse IL

06-13-2002, 02:44 PM