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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Mass Air Flow (MAF) & Intake Air Temperature (IAT) Sensor On-Vehicle Inspection

Mass Air Flow (MAF) & Intake Air Temperature (IAT) Sensor On-Vehicle Inspection

NOTE: Before performed this inspection, be sure to read the Precautions for ECM Circuit Inspection.

1. Disconnect MAF & IAT sensor connector.
2. Check that voltage of MAF & IAT sensor connector (harness side) between terminals "3" and "4" is battery voltage when ignition switch is in ON position.
If faulty condition is found, check power supply circuit, ground circuit and connections.







3. Check that MAF sensor signal and IAT sensor signal are output properly.
If faulty condition is found, check the following.
- Wire harness and connections.
- MAF & IAT sensor