Air Flow Meter/Sensor: Testing and Inspection

1NZ-FE ENGINE CONTROL SYSTEM: MASS AIR FLOW METER: ON-VEHICLE INSPECTION

ON-VEHICLE INSPECTION
NOTICE:
- Perform the mass air flow meter inspection according to the procedures below.
- Only replace the mass air flow meter when both the LONG FT#1 value and MAF value in the DATA LIST (with the engine stopped) are not within the normal operating range.

1. INSPECT MASS AIR FLOW METER
(a) Perform confirmation driving pattern.
(1) Connect the Techstream to the DLC3.
(2) Turn the ignition switch to ON.
(3) Turn the ignition switch to ON.
(4) Clear the DTCs DTC Check / Clear.
(5) Start the engine and warm it up with all the accessory switches OFF (until the engine coolant temperature is 75°C (167°F) or more).
(6) Drive the vehicle at 50 km/h (31 mph) or more for 3 to 5 minutes *1.
(7) Allow the engine to idle for 2 minutes *2.
(8) Perform steps *1 and *2 at least 3 times.





(b) Read the value using the Techstream (LONG FT#1).
(1) Select the following menu items: Powertrain / Engine and ECT / Data List / LONG FT #1.
(2) Read the values displayed on the tester.
Standard value:
Within -20 to 20 %
If the result is not within the specified range, perform the inspection below.
(c) Read the value using the intelligent tester (MAF).
NOTICE:
- Turn off the engine.
- Perform the inspection with the vehicle indoors and on a level surface.
- Perform the inspection of the mass air flow meter while it is installed into the air cleaner case (installed on the vehicle).
- During the test, do not use the exhaust air duct to perform suction on the exhaust pipe.
(1) Turn the ignition switch to ACC.
(2) Turn the ignition switch ON (do not run the engine).
(3) Turn the tester ON.
(4) Select the following menu items: Powertrain / Engine and ECT / Data List / MAF.
(5) Wait 30 seconds, and read the values on the intelligent tester.
Standard condition:
Less than 0.28g/sec

- If the result is not as specified, replace the mass air flow meter.

- If the result is within the specified range, investigate the cause of the extremely rich or lean air fuel ratio P0171.