Actron CP9087 Service Manual

Contents

Actron CP9087 Service Manual Manual pdf 42 page image

2-34Testing SensorsSection 2FLOW- F + TypicalMAFSensor• Related trouble codes sent by computer.• Driveability problems such as hard starting,rough idle, stalling, hesitation, stumble, surging,knocking (pinging), poor fuel economy, blackexhaust smoke, backfiring, catalytic converteroverheating or no torque converter lock-up.When to TestLocation The sensor is mounted in the engine incoming airducts—typically just behind the air cleaner assem-bly or near the throttle body.How it isused?The computer needs to know incoming air flow toproperly adjust air/fuel mixture and ignition timingfor varying engine load and operating conditions.What is It? This sensor is an electronic module which sends asignal to the computer indicating the amount of airentering the engine. Depending upon sensor type,the signal may be a dc voltage or a frequency. Thesignal level increases (higher voltage or frequency)as the air flow increases.Within the sensor is a heated wire located in thepath of incoming air. The module determines airflow by measuring the temperature drop of theheated wire as air passes around it.Mass Air Flow (MAF) Sensors