The Mass Air Flow (MAF) sensor uses a hot wire sensing element to measure the amount of air entering the engine. Air passing over the hot wire causes it to cool. This hot wire is maintained at 200°C (392°F) above ambient temperature as measured by a constant cold wire.
The current required to maintain the temperature of the hot wire is proportional to the air mass flow. The MAF sensor then outputs an analog voltage signal to the PCM proportional to the intake air mass. The PCM calculates the required fuel injector pulse width in order to provide the desired air/fuel ratio.
Removal & Installation
- Disconnect the negative battery cable.
- Remove the air intake assembly.
- Release the air cleaner clamp. Separate the inlet side from the outlet side of the air cleaner.
- Remove the MAF assembly.
- Disconnect the MAF sensor electrical connector.
- Remove the nuts and separate the MAF sensor from the MAF sensor plate.
Installation is the reverse order of removal. Tighten the nuts to 89 inch lbs. (10 Nm).
Inspect the air cleaner and inlet duct. Check all engine vacuum hoses for damage, leaks, cracks, kinks and proper routing. Check Electronic Control (EC) system wiring harness for proper connections, bent or broken pins, corrosion, loose wires and proper routing. Check the powertrain control module (PCM), sensors, and actuators for physical damage.
Basic circuit checks help to minimize pinpoint test steps by providing a procedure to diagnose harness faults associated with the Electronic Engine Control (EC) System: