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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Air Flow Meter/Sensor: Testing and Inspection

Air Flow Meter Schematic:






1. Check airflow meter body for cracks or other damage. Replace unit if problems are detected.
2. Verify that measuring core moves in and out smoothly. If not, correct problem or replace airflow meter.

Resistance Values:






3. Measure resistance across terminals as described on image chart. If not as specified, replace airflow meter.

Airflow meter input voltage can be checked at ECU terminal 2B. With ignition "ON" (engine not running), voltage should be approximately 4.0V. At idle, voltage should be 2.5 - 3.5V.