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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IAT

The scan tool range is -40°C to 120°C (-40°F to 250°F): The IAT sensor is a thermistor. The PCM monitors the voltage on the IAT sensor signal circuit. When the IAT sensor is cold (internal resistance high), the PCM sees a high signal voltage. The signal voltage and the internal resistance of the sensor decrease as the engine becomes warm. The scan tool displays default values of -40°C or -40°F when there is an open in the IAT sensor signal circuit.