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)

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Knock Sensor: Testing and Inspection

Knock Sensor Connector:





1. Disconnect Knock Sensor sub-harness connector.


Knock Sensor Test:





2. Check continuity between terminal (a) and ground. Continuity should exist.
If no continuity exists, inspect Knock Sensor sub-harness.
Code 34

If sub-harness is OK, replace Knock Sensor.