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 or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Knock Sensor: Diagrams

U1 (Knock Control Sensor (Bank 1 Sensor 1)):



U2 (Knock Control Sensor (Bank 2 Sensor 1)):



U3 (Knock Control Sensor (Bank 1 Sensor 2)):



U4 (Knock Control Sensor (Bank 2 Sensor 2)):