Air Flow Meter/Sensor: Testing and Inspection
ON-VEHICLE INSPECTION1. CHECK MASS AIR FLOW METER
NOTE:
- Perform the MAF meter inspection by following the procedures.
- Only replace the MAF 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.
a. Perform confirmation driving pattern.
1. Connect the intelligent tester to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the tester on. (4) Clear the DTCs.
5. Start the engine and warm it up with all accessory switches off (until the engine coolant temperature is 75°C (167°F) or more).
6. Drive the vehicle at 31 mph (50 km/h) or more for 3 minutes or more (*1).
7. Allow the engine to idle (accelerator pedal pulley released) for 2 minutes or more (*2).
8. Perform steps (*1) and (*2) at least 3 times or more.
b. Read values using the intelligent tester (LONG FT#1).
1. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / LONG FT#1.
2. Read the values displayed on the tester.
Standard value: Within -15 to +15%
If the result is not within the specified range, perform the inspection.
c. Read values using the intelligent tester (MAF).
NOTE:
- Turn off the engine.
- Perform the inspection with the vehicle indoors and on a level surface.
- Perform the inspection of the MAF meter while it is installed to the air cleaner case (installed to the vehicle).
- During the test, do not use the exhaust air duct to perform suction on the exhaust pipe.
1. Turn off the engine (do not run the engine).
2. Turn the engine switch on (IG).
3. Turn the tester on.
4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF.
5. Wait 30 seconds, and read the values on the intelligent tester.
Standard condition: Less than 0.56 g/sec
- If the result is not as specified, replace the MAF meter.
- If the result is within the specified range, inspect the cause of the extremely rich or lean air fuel ratio.