A 5-volt power is applied to the Mass Air Flow (MAF) Sensor output terminal from the ECM/PCM. The sensor generates a pulse signal when the output terminal and ground are opened/closed (opened/short).
Removal & Installation
- Disconnect the negative battery cable.
Replacing the sensor requires disconnecting the electrical connector, then carefully removing the lid of the air filter housing.
NOTEHandle the sensor assembly carefully, protecting it from impact, extremes of temperature and/or exposure to shop chemicals.
- Installation is the reverse of the removal procedure.
- Connect a suitable scan tool to read data.
Start the engine and run at idle. Warm up the engine to normal operating temperature: 176° to 205°F.
- The standard value during idling should be 10 Hz or more.
- When the engine is revved, the frequency should increase according to the increase in engine speed.
- If the checks above do not meet the specification, disconnect the sensor connector and measure at the harness side.
- Turn the ignition switch to "ON" position, and measure the voltage between terminal 4 and ground. Voltage should be battery positive voltage.
- Turn the ignition switch to "LOCK" (OFF) position.
- If not within specifications, check and repair/replace the connector(s), harness wire between MFI relay and/or the MFI relay.
- If within specifications, disconnect the sensor connector and measure at the harness side.
- Turn the ignition switch to "ON" position and measure the voltage between terminal 3 and ground. Voltage should be between 4.8 and 5.2 volts.
- Turn the ignition switch to "LOCK" (OFF) position and check for the resistance between terminal 5 and ground. Resistance be less than 2 ohm.
- If all checks above meet the specifications, replace the sensor.
- If any check above does not meet the specifications, replace the ECM/PCM.