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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Oil Temperature Sensor/Switch: Testing and Inspection

Oil pressure switch

1. Stop the engine to check continuity between the terminal and ground.
2. Start the engine to check continuity between terminal and ground.




3. Change the switch if it deviates from standard value.
4. Disconnect the connector warning switch and the ground terminal located at the wire harness side connector.




5. Turn the ignition switch on and check if the warning lamp lights on.
Test the bulb or check the wire harness when it fails to light on.