Air Flow Meter/Sensor: Testing and Inspection
MASS AIR FLOW (MAF) SENSOR INSPECTIONNOTE: Perform the following test only when directed.
1. Visually inspect for damage, cracks, terminal bends and terminal rust on the MAF sensor.
- If any of the above are found, replace the MAF sensor.
- If the MAF sensor is okay, but PID value or PCM terminal 88 voltage are out of specification, carry out the "Circuit Open/Short Inspection".
Circuit Open/Short Inspection
1. Remove the PCM.
2. Connect the SST (104 Pin Breakout Box) to the PCM as shown.
3. Tighten the connector attaching screw.
Tightening torque
7.9 - 10.7 N.m {80 - 110 kgf.cm, 69.5 - 95.4 in.lbf}
4. Inspect for an open or short circuit in the following wiring harnesses by probing the applicable sensor and SST (104 Pin Breakout Box) terminals with ohmmeter leads.
- If there is an open or short circuit, repair or replace wiring harnesses.
- If there is no open or short circuit, replace the MAF sensor.
Open circuit
- MAF signal circuit (MAF sensor connector terminal B and PCM connector terminal 88)
- Power circuit (MAF sensor connector terminal C and main relay terminal D through common connector)
- GND circuit (MAF sensor connector terminal A and PCM connector terminal 103 through common connector)
Short circuit
- MAF signal circuit (MAF sensor connector terminal B and PCM connector terminal 88 to GND)
- Power circuit (MAF sensor connector terminal C and main relay terminal D through common connector to GND)
5. Reconnect the MAF sensor connector.
Specification:
NOTE: The scan tool shows the MAF rate and load value.