Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la
If it fails: lemon-manuals.org.ua

Or, hide this message: temporarily or permanently

Knock Sensor: Description and Operation


LOCATION

Sensor mounted in engine block.

PURPOSE

Sensor informs Powertrain Control Module (PCM) detonation has occurred.

PCM retards timing until detonation is no longer detected.

Knock Sensor Operation:





OPERATION

Sensor generates a signal when spark knock, (pre-ignition, detonation, or pinging) occurs in combustion chamber, (due to vibration of the piezo electric crystal).