Mass Air Flow (MAF) Sensor On-Vehicle Inspection
NOTE:
Use voltmeter with high-impedance (10 kohm/V minimum) or digital type voltmeter.
- Remove ECM (PCM) cover from bracket.
- With ignition switch OFF, disconnect MAF sensor connector (1).
- Connect voltmeter to "C32-3" terminal (2) of MAF sensor connector (1) disconnected and ground.
- Turn ignition switch ON and check that voltage is battery voltage. If not, check if wire harness is open or connection is poor.
- Turn ignition switch OFF and connect MAF sensor connector to MAF sensor.
- Turn ignition switch ON and check voltage between "C51-3-23" and "C51-3-20" terminal.
Voltage between "C51-3-23" and "C51-3-20" terminal
0.5-1.0V
- Start engine and check that voltage is lower than 5 V and it rises as engine speed increases.
(Reference data: 1.5-1.8 V at specified idle speed)
If check result is not as specified above, cause may lie in wire harness, coupler connection, MAF sensor or ECM (PCM).