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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Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

Engine Coolant Temperature Sensor Ohm Test:





1. Disconnect Engine Coolant Temperature Sensor harness connector.
2. Check resistance as shown in the figure.

Resistance Values:
2.1 - 2.9k Ohms at 20°C (68°F)
0.68 - 1.0k Ohms at 50°C (122°F)
0.30 - 0.33k Ohms at 80°C (176°F)

If Not Good, replace Engine Coolant Temperature Sensor.