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

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Coolant Temperature Sensor/Switch (For Computer): Description and Operation

Engine Coolant Temperature (ECT) Sensor Location:






PURPOSE
The Engine Coolant Temperature (ECT) Sensor measures coolant temperature to supply the Engine Control Module (ECM) with engine temperature data.

OPERATION
As coolant temperature increases, sensor resistance decreases. The ECM receives sensor information as resistance to ground. Coolant temperature information is used to determine proper fuel delivery.