Toyota Sienna Service Manual: On-vehicle inspection

1. INSPECT MASS AIR FLOW METE

NOTICE:

•  Perform the mass air flow (MAF) meter inspection by following the procedures below.
•  Only replace the MAF meter when the MAF value in the DATA LIST (with the engine stopped) are not within the normal operating range or there is foreign matter on the MAF meter platinum hot wire (heater).

1.  Read the values using the intelligent tester (MAF).

NOTICE:

•  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 the ignition switch to the ON position (do not start the engine).
2.  Turn the tester on.
3.  Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / PRIMARY / MAF.
4.  Wait 30 seconds, and read the values on the intelligent tester.

• Standard condition: Less than 0.70 g/s 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.