Toyota Prius: Mass Air Flow Meter

• On-vehicle Inspection
• Removal
• Installation

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

Pre-procedure1

(a) Read the value of Data List item "Mass Air Flow Sensor" using the GTS.

NOTICE:

Perform the inspection of the mass air flow meter sub-assembly while it is installed to the air cleaner cap sub-assembly (installed to the Toyota Prius vehicle).

(1) Check and ensure the following conditions:

(2) Put the engine in Inspection Mode (Maintenance Mode).

Powertrain > Hybrid Control > Utility

Tester Display
Inspection Mode

(3) Start the engine.

Procedure1

(b) According to the display on the GTS, read the Data List when the engine is running.

Powertrain > Engine > Data List

Tester Display
Mass Air Flow Sensor

Standard Condition:

GTS Display	Condition	Specified Condition	Result
Mass Air Flow Sensor	Idling with warmed up engine (inspection mode [maintenance mode], not charge control)	1.0 to 3.0 gm/sec	gm/sec
Mass Air Flow Sensor	Warmed up engine, 2500 rpm (inspection mode [maintenance mode])	4.5 to 8.5 gm/sec	gm/sec

If the result is not as specified, clean the mass air flow meter sub-assembly.

If the result is within the specified range, inspect the mass air flow meter sub-assembly.

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Post-procedure1

(c) None

2. CLEAN MASS AIR FLOW METER SUB-ASSEMBLY

NOTICE:

If the mass air flow meter sub-assembly is removed and installed 10 times or more, the thread of the hole of the mass air flow meter sub-assembly may be damaged. Therefore, do not loosen the screws of the mass air flow meter sub-assembly.

Pre-procedure1

(a) Remove the air cleaner cap sub-assembly.

Procedure1

*1	Mass Air Flow Meter Sub-assembly
*a	Air Blow Gun
*b	10 mm (0.394 in.)
*c	Airflow Hole

(b) Clean the mass air flow meter sub-assembly.

(1) Using an air blow gun, clean the hole of the mass air flow meter sub-assembly by applying approximately 10 intermittent bursts of air to the airflow hole at a pressure of approximately 392 to 981 kPa (4.0 to 10.0 kgf/cm2, 57 to 142 psi).

*a Air Blow Duration *b 3 to 6 Seconds *c 1 Second *d Air Blowing *e Air Stopped

Post-procedure1

(c) Install the air cleaner cap sub-assembly.

3. PERFORM INITIALIZATION

(a) Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

HINT:

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Removal

REMOVAL

CAUTION / NOTICE / HINT

The necessary procedures (adjustment, calibration, initialization or registration) that must be performed after parts are removed and installed, or replaced during mass air flow meter sub-assembly removal/installation are shown below.

Necessary Procedures After Parts Removed/Installed/Replaced

Replaced Part or Performed Procedure	Necessary Procedure	Effect/Inoperative Function when Necessary Procedure not Performed	Link
Replacement of mass air flow meter sub-assembly	Inspection after repair	Poor idle, etc. Engine start function, etc.

CAUTION / NOTICE / HINT

COMPONENTS (REMOVAL)

Procedure		Part Name Code
1	MASS AIR FLOW METER SUB-ASSEMBLY	22204		-	-

PROCEDURE

1. REMOVE MASS AIR FLOW METER SUB-ASSEMBLY

NOTICE: If the mass air flow meter sub-assembly has been struck or dropped, replace it.

Installation

INSTALLATION

CAUTION / NOTICE / HINT

COMPONENTS (INSTALLATION)

Procedure		Part Name Code
1	MASS AIR FLOW METER SUB-ASSEMBLY	22204		-	-
2	PERFORM INITIALIZATION	-	-	-

PROCEDURE

1. INSTALL MASS AIR FLOW METER SUB-ASSEMBLY

NOTICE: If the mass air flow meter sub-assembly has been struck or dropped, replace it. If reusing the mass air flow meter sub-assembly, be sure to inspect the gasket. Make sure that the gasket is not cracked or moved out of place when installing the mass air flow meter sub-assembly.

2. PERFORM INITIALIZATION

(a) Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

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