See Figure 1
The Mass Air Flow (MAF) Sensor measures the amount of air entering the engine during a given time. The ECM uses the mass airflow information for fuel delivery calculations. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle.
See Figure 2
- Backprobe with a high impedance voltmeter between MAF sensor terminals C and B.
- With the ignition ON engine off, verify that battery voltage is present.
- If the voltage is not as specified, either the wiring to the MAF sensor, fuse or the ECM may be faulty. Correct any wiring or ECM faults before continuing test.
- Disconnect the voltmeter and backprobe with a frequency meter between MAF sensor terminals A and B.
- Start the engine and wait until it reaches normal idle speed and verify that the MAF sensor output is approximately 2000 Hz.
- Slowly raise engine speed up to maximum recommended rpm and verify that the MAF sensor output rises smoothly to approximately 8000 Hz.
- If MAF sensor output is not as specified the sensor may be faulty.
REMOVAL & INSTALLATION
See Figures 3, 4 and 5
- Disconnect the negative battery cable.
- Unplug the electrical connector.
- Remove the air intake duct and the sensor.
- Installation is the reverse of removal.